2010:013 MASTER'S THESIS

2010:013

M A S T E R ' S T H E S I S

Camera Design forPico and Nano Satellite Applications

Kashif Gulzar

Luleå University of Technology

Master Thesis, Continuation Courses Space Science and Technology

Department of Space Science, Kiruna

2010:013 - ISSN: 1653-0187 - ISRN: LTU-PB-EX--10/013--SE

Computer Science VII: Robotics and Telematics

Camera Design for Pico and Nano Satellite

Applications

Thesis submitted in partial fulfillment of the requirement for the degree of

Master of Science in Space Technology

Kashif Gulzar

Würzburg, September 25, 2009

Project Supervisors:

© Kashif Gulzar September 2009

Prof. Dr.-Ing. Hakan Kayal

Spacecraft Control and System Design

Computer Science VII

University of Würzburg, Germany

Dr. Victoria Barabash

Senior Lecturer

Department of Space Science

Luleå University of Technology,Sweden

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Acknowledgements

This research project was completed at University of Würzburg in the department of

“Computer Science VII Robotics and Telematics”, during the last semester of studies for

Spacemasters program. Firstly, I would like to thank my thesis supervisor Prof. Dr.-Ing.

Hakan Kayal. He has provided me opportunity to work on this project related to my

interest. He provided me much useful explanation and full support during the execution

and all the way through design, development and testing of process. I would like to pay

special thanks Prof. Dr. Klaus Schilling from Würzburg, Germany and Dr. Victoria

Barabash from Kiruna, Sweden to provide wealth-full knowledge resources and support

during this entire Spacemasters program. Especially, I would like to acknowledge their

effort for their arrangement of guest lecturers, delivered by people from the space

industry. I also would like to thank for the technical support provided by Mr. Dieter

Ziegler in robotics lab during the hardware development of this camera. He has really

supported me and guided me for the quick acquisition of related component on time.

I would also like to acknowledge the support received from OmniVision Sensor

Company, for providing the sensor datasheet and for acknowledging my request to

provide the sensor which makes it possible for its assessment and PCB design on the

preplanned schedule.

Most importantly and finally, I would like to thanks my parents for their patience and

encouraging support during the time I spent abroad for my MS-thesis. I also would like to

pay special thanks to my brothers for their support during this last semester.

Kashif Gulzar

Sep 2009

iii

Master thesis Abstract

Degree Program: MSc in Space Technology

Title: Camera Design for Pico and Nano Satellite Applications

Author: Kashif Gulzar

Date: 30.September.2009 Number of Pages: 115

Department: Computer Science VII Word Count: 17,779

Faculity: Faculatiy of Robotic and Telemetics

Supervisors: Prof. Dr.-Ing. Hakan Kayal

Dr. Victoria Barabash

Small scale camera is now enviable as an attractive future candidate for the low cost Pico and Nano satellites. These small satellites provided platform for developing cost effective applications. Well designed camera hardware with certain capabilities can support multiple on-board applications. Small camera can be integrated as Star Sensor, Earth detector and can be used for Remote Sensing applications. It could be used to be specific for Earth and Moon observation missions. Space debris monitoring, inspection of nearby space objects especially, nearby satellites and observation of Translucent Lunar Phenomenon (TLP) are other important candidate applications for these low cost satellite missions exploiting the use of a small camera. These small low cost satellites with camera can also be used for astronomical purposes. The purpose of this thesis is to investigate these applications and design and construct a camera for small satellites with the range from Pico to Nano satellite, a camera that could support single as well as multiple applications depending on application scenario with very little or no modification in hardware design.

Project’s main task is to develop and construct the camera. This design involved the design of imager or sensor board along with processing board. A preliminary but related optics assessment associated to particular application has been carried out. Feasibility and scale of camera related to different mission driver’s tradeoffs e.g. optics, mass, power, spatial and temporal resolution, memory, processing or application requirements, etc. have been investigated. A suitable imaging sensor was selected and imaging system have been constructed & tested as the outcome of this thesis.

Keywords: Imager, Picosatellite, Nanosatellite, Earth observation, Space Debris Monitoring, Translucent Lunar Phenomenon, Resolution, Remote Sensing.

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Table of Contents

1. Introduction ............................................................................................................................... 1

1.1 Project timeline ................................................................................................................ 2

1.2 Achievements................................................................................................................... 2

1.3 Background ...................................................................................................................... 3

2. Requirements study ................................................................................................................... 5

2.1 Satellite classes definition ................................................................................................ 5

2.1.1 Nanosatellite ............................................................................................................ 5

2.1.2 Picosatellite .............................................................................................................. 5

2.1.3 CubeSat standard ..................................................................................................... 6

2.2 Minimum requirement in term of satellite class ............................................................. 6

2.3 Image sizes and data volumes analysis ............................................................................ 6

2.4 Requirement analysis for application ............................................................................ 10

2.4.1 Pixel size ................................................................................................................. 12

2.4.2 Feasibility analysis of Transient Lunar Phenomena ............................................... 13

2.4.3 Earth observation ................................................................................................... 17

2.4.4 Star sensor ............................................................................................................. 19

2.4.5 Space debris monitoring ........................................................................................ 20

2.4.6 Overall requirements ............................................................................................. 23

2.4.7 Telescope size ........................................................................................................ 23

3. Previous Work ......................................................................................................................... 25

3.1 Existing satellites with camera ....................................................................................... 25

3.1.1 CubeSat XI‐IV .......................................................................................................... 25

3.1.2 COMPASS‐1 ............................................................................................................ 26

3.1.3 AAU‐CUBESAT ........................................................................................................ 26

3.1.4 CanX‐1 .................................................................................................................... 26

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3.2 Existing hardware solutions ........................................................................................... 27

3.2.1 C628 enhanced JPEG module ................................................................................ 27

3.2.2 C328R Jpeg compression VGA camera module [C328R] ........................................ 29

3.2.3 C3188A sensor module .......................................................................................... 30

3.2.4 OV7648FB camera module .................................................................................... 31

3.2.5 CMUCAM 3 camera ................................................................................................ 32

3.3 Existing optics procurement and design solutions ........................................................ 33

3.3.1 LENS selection ........................................................................................................ 33

3.3.2 Optics design solutions for small size satellite ....................................................... 35

4. Architecture design .................................................................................................................. 38

4.1 System architecture ....................................................................................................... 38

4.2 Sensor ............................................................................................................................ 41

4.2.1 CCD Vs CMOS ......................................................................................................... 41

4.3 Available CMOS sensors survey and selection ............................................................... 43

4.4 Sensor features .............................................................................................................. 45

4.4.1 Block diagram of the sensor OV7720 ..................................................................... 47

4.4.2 Sensor parameters ................................................................................................. 47

4.4.3 Camera SCCB interface for configuration .............................................................. 49

4.4.4 Prototype optics for sensor ................................................................................... 49

4.5 Processor market survey ................................................................................................ 49

4.5.1 Selected processor features ................................................................................... 51

4.6 FIFO for image buffering ................................................................................................ 56

4.6.1 Al440B description ................................................................................................. 57

4.6.2 FIFO features [AVERLOGIC] .................................................................................... 58

4.7 System block diagram based on selected components ................................................. 59

5. Schematic design ..................................................................................................................... 61

5.1 Sensor interface with FIFO ............................................................................................. 61

5.2 Serial bus interface to FIFO ............................................................................................ 65

5.2.1 Interface connection of sensor board with processor. .......................................... 66

5.3 Sensor read operation ................................................................................................... 67

5.4 SCCB programming ........................................................................................................ 68

5.5 Memory .......................................................................................................................... 69

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5.6 CAN/RS232 Interface ..................................................................................................... 69

5.7 Debugging interface and processor clocking ................................................................. 70

5.8 Power supply .................................................................................................................. 71

5.9 Power budgets and alternatives .................................................................................... 71

5.10 Mass budgets ................................................................................................................. 72

5.11 USB interface. ................................................................................................................ 73

5.12 Dimension ...................................................................................................................... 73

5.13 Modular printed circuit boards ...................................................................................... 73

6. Software .................................................................................................................................. 75

6.1 Software for image acquisition ...................................................................................... 75

6.1.1 Software for sensor test application ...................................................................... 76

7. System testing ......................................................................................................................... 83

7.1 Images acquired for alignment problems ...................................................................... 83

7.2 Testing of SCCB bus interface ........................................................................................ 84

7.3 Night image of the sky ................................................................................................... 85

7.4 Near and far images ....................................................................................................... 86

7.5 Image of the Sun and sky at day time ............................................................................ 87

8. Conclusion & future recommendations ................................................................................... 88

9. References ............................................................................................................................... 91

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List of Tables

Table 1: Sensor volume calculation and its impact on memory sizing ............................................ 9

Table 2: Transmission time to send single image for different sensor format ............................... 10

Table 3: Imager specifications CanX-1[CanX-1] .......................................................................... 27

Table 4: C628 enhanced JPEG module specifications [C628] ...................................................... 27

Table 5: C3188A camera module specifications [C3188A] .......................................................... 31

Table 6: Key specifications OV7648FB camera module [OV7648FB] ........................................ 32

Table 7: Small optical lenses ......................................................................................................... 33

Table 8: Selected sensor comparison ............................................................................................. 44

Table 9: OV7720 sensor parameters [OV7720] ............................................................................ 48

Table 10: FIFO for image acquisition selection table .................................................................... 57

Table 11: FIFO write interface signals .......................................................................................... 62

Table 12: FIFO read interface signals ............................................................................................ 63

Table 13: Processor board connector signals description .............................................................. 64

Table 14: Power configuration with now optional component removed ....................................... 71

Table 15: For CubeSat with sensor board directly interface with OBC(Alternative-1) ................. 71

Table 16: For CubeSat allowing the use of power up to 1 W* ...................................................... 72

Table 17: Prototype mass ............................................................................................................... 73

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List of Figures

Figure 1: Project timeline ................................................................................................................. 2

Figure 2: Würzburg ground station visibility ................................................................................... 7

Figure 3: Focal length concept ....................................................................................................... 10

Figure 4: TLP observation scenario ............................................................................................... 14

Figure 5: Focal length vs. ground sampling distance for Moon .................................................... 15

Figure 6: Focal length vs. aperture ................................................................................................ 16

Figure 7: Camera use as Earth observation scenario ..................................................................... 17

Figure 8: Focal length vs. Ground Sampling Distance for Earth observation ............................... 18

Figure 9: Focal length vs. aperture for Earth observation .............................................................. 19

Figure 10: Earth objects in orbit [NASA-OD] ............................................................................... 21

Figure 11: Focal length vs. space debris size ................................................................................. 22

Figure 12: CubeSat images taken University of Tokyo by CubeSat [PRISM XI-IV] ................... 25

Figure 13: Functional diagram C628 module ................................................................................ 28

Figure 14: C328R Jpeg compression VGA camera module [C328R] ........................................... 29

Figure 15: Block diagram C328R camera module [C328R] .......................................................... 30

Figure 16: C3188A camera module [C3188A] .............................................................................. 30

Figure 17: OV7648FB camera module [OV7648FB] .................................................................... 31

Figure 18: CMUcam3 block diagram [CMUCAM3] .................................................................... 33

Figure 19: Infinite conjugate micro lenses [EDMUND]................................................................ 35

Figure 20: C mount adapter [EDMUND] ...................................................................................... 35

Figure 21: (a) Conventional lens. (b) Annular folded optics concept [TREMBLAY07] .............. 36

Figure 22: PRISM satellite deployable optics [PRISM] ................................................................ 37

Figure 23: Camera architecture-1 [BEYONDLOGIC] .................................................................. 38

Figure 24: Proposed system architecture-2 .................................................................................... 40

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Figure 25: Sensor OV7720 ............................................................................................................ 46

Figure 26: Internal block diagram sensor ...................................................................................... 47

Figure 27 Typical dynamic instruction usage [FURBER] ............................................................. 50

Figure 28: Processor architecture [LPC2468] ................................................................................ 52

Figure 29: AL440B internal block diagram [AVERLOGIC] ........................................................ 58

Figure 30: System block diagram .................................................................................................. 59

Figure 31: Interfacing between sensor and FIFO ........................................................................... 61

Figure 32: Connector for FIFO interfacing with processor board ................................................. 64

Figure 33: AL440B Serial bus write timing ................................................................................... 66

Figure 34: AL440B Serial Bus read timing ................................................................................... 66

Figure 35: Sensor board connector pin out .................................................................................... 66

Figure 36: Interrupt latency for VSYNC or frame pulse ............................................................... 68

Figure 37: Sensor register programming logic through SCCB using I2C[SCCB] ........................ 69

Figure 38: Debugging interface logic ............................................................................................ 70

Figure 39: Sensor PCB................................................................................................................... 73

Figure 40: Sensor PCB size compared to coin ............................................................................... 74

Figure 41: Processor PCB .............................................................................................................. 74

Figure 42: Camera system, Euro coin and standard size card side by side .................................... 74

Figure 43: State flow diagram for microcontroller software ......................................................... 75

Figure 44: Sensor testing program user Interface for Acquisition ................................................. 77

Figure 45: Use case diagram for sensor test application ................................................................ 78

Figure 46: Serial control configuration panel ................................................................................ 79

Figure 47: Gain control configuration panel .................................................................................. 79

Figure 48: Advanced sensor control configuration panel .............................................................. 79

Figure 49: Testing software class diagram .................................................................................... 80

Figure 50: Bayer to RGB conversion algorithm ............................................................................ 82

Figure 51: Misaligned color image with test pattern ..................................................................... 83

Figure 52: Misaligned color image without test pattern ................................................................ 83

Figure 53: Perfectly aligned color RGB image bar test pattern sky at the background ................. 84

Figure 54: Perfectly aligned color RGB image of the blue sky without test pattern ..................... 84

Figure 55: Color RGB image with full red gain settings ............................................................... 85

Figure 56: Color RGB image with full blue gain settings ............................................................. 85

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Figure 57: Color RGB image with full green gain settings ........................................................... 85

Figure 58: Image with no AGC settings ........................................................................................ 85

Figure 59: Across the sky and across the night .............................................................................. 86

Figure 60: Image of far object ....................................................................................................... 86

Figure 61: Image of object relatively close to camera ................................................................... 86

Figure 62: Image acquired for clear sky with clouds .................................................................... 87

Figure 63: Image acquired for sun over Universität Würzburg Mensa building ........................... 87

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List of Acronyms

SSA: Space Situational Awareness COTS: Commercial, off-the-shelf ESA: European Space Agency CIF: Common Intermediate Format QVGA: Quarter Video Graphics Array VGA: Video Graphics Array CANX: Canadian Advanced Nanospace eXperiment TLP: Transient Lunar Phenomenon TSD: Target Sampling Distance GSD: Ground Sampling Distance CMOS: Complementary Metal Oxide Semiconductor FOV: Field of View CPLD: Complex Programmable Logic Device FPGA: Field Programmable Gate Array FIFO: First In First Out DMA: Direct Memory Access DSP: Digital Signal Processing ARM: Advanced RISC Machines Ltd RISC: Reduced Instruction Set Computer SNAP1: Surrey Nanosatellite Applications Platform JPEG: Joint Photographic Experts Group DSC: Digital Still Camera BGA: Ball Grid Array NTSC: National Television System(s) Committee PAL: Phase Alternating Line MMC: MultiMediaCard FAT: File Allocation Table DR: Dynamic Range SNR: Signal-to-Noise Ratio S/N: Signal-to Noise Ratio CCD: Charge-Coupled Device SXGA: Super eXtended Graphics Array CLCC: Ceramic Leadless Chip Carrier Packages AEC: Automatic Exposure Control AGC: Automatic Gain Control AWB: Automatic White Balance ABF: Automatic Band Filter

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ABLC: Automatic Black Level Calibration SCCB: Serial Camera Control Bus EFL: Effective Focal Length UART: Universal Asynchronous Receiver Transmitter CAN: Control Area Network SPI: Serial Peripheral Interface OBC: On Board Computer IC: Integrated Circuit I2C: Inter-Integrated Circuit PCB: Printed Circuit Board JTAG: Joint Test Action Group RTC: Real-Time Clock

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Kashif Gulzar, MSc Dissertation

Chapter 1

Introduction

Small satellite in the range of Picosat and Nanosatellites are the cost effective solution to

investigate certain applications. These satellites offer the platform to develop and test

COTS based solution. Imaging systems integration on these small satellites would be

helpful to realize certain applications for future launch of these small satellites. Some

small satellite especially CubeSats have already used small camera for acquiring images.

Imaging capability on these small satellites opens the horizon for many new possibilities

for future small satellite mission. Some of these capabilities have already been explored

by university satellites producers. Numerous applications and support task for Pico and

Nano satellite like, spacecraft Attitude determination from Star Sensor, Earth & Moon

Observation, Space Debris Monitoring, inspection and monitoring of nearby objects and

other applications of ESA’s Space Situational Awareness (SSA) Program require the use

of small camera for low cost satellite missions.

Therefore, a miniaturized camera to support these basic and advanced applications needs

to be developed. Requirements of these applications are very demanding and interrelated

with Pico and Nano satellite missions. Different aspect of Pico and Nano size satellite

missions imposes the constraints on the design of this camera. Particularly an imaging

system capable of supporting these applications could provide a platform for developing

further application.

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1.1 Project timeline

The project was started on time on 01.04.2009 April. Following is the timeline for the

required level of activities carried out during the commencement of the project.

Figure 1: Project timeline

1.2 Achievements

Camera PCB and hardware has been designed and tested.

Images have been acquired, for functional verification.

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1.3 Background

Many universities have launched CubeSats, some of these CubeSat are launched as triple

configuration CubeSat. University of Wuerzburg has also launched its second satellite on

23rd September from the PSLV rocket in Sriharikota space center in India. Satellite

missions have different requirements and different objectives. However, having the

possibility of camera on small satellite particularly CubeSats open new horizons for many

applications. Mostly, the camera design on satellite is dictated by optics design and is

actually very much demanding for certain applications. There are many other mission

applications related to small scale satellites in the range of Pico and Nano class where the

use of small camera will be valuable asset.

Since small scale satellites have very demanding and limited mass, power, and

transmission budget specifications therefore, mostly the design constraints prevent the

use of small scale camera. Many university missions are based on CubeSat which

provides opportunity to use miniaturized technology. Small camera have been used in

small satellite specially CubeSat in the past for imaging purpose. On-board camera can be

used for multiple or single application.

Conventional satellites are very costly in term of launch and manufacturing budgets.

Their Risk assessment and analysis offer only the use of space proven or space mature

technology that provide little risk to missions failure. In such satellites adding multiple

applications to the same on board imager would cause additional risk to the camera

failure therefore, in general it’s avoided. But for smaller platform especially the CubeSat

the risk assessment and risk management does allow the use of multiple applications on

board supplementary to the same imager. They provide the platform for the applications

to be tested until they get mature to a level where it can be safely used for conventional

satellites. Since there are different optical demands for different objectives, some time it

is desirable to use definite optics for one solution and design cannot be compromised

with respect to application. In such case, camera in other mission with the modification of

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optics can be utilized for other purposes like close inspection of nearby objects (which

may include other satellites, Space Debris). Same camera can be used to for space debris

monitoring and for maintaining space objects catalog. Earth observation for Earth based

imaging and Moon observation to observe certain TLP to take images at low cost. Images

obtained with CubeSat can be proved to be useful resource in remote sensing business to

some extent.

Multipurpose camera can add another flexibility to the mission as same camera could be

used to take images and also perform other vector calculation like for Star Sensor.

However, these application benefits are yet to be explored. The possibility of using a

camera on a CubeSat for multiple purposes can also provide usability benefits.

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Chapter 2

Requirements study

Preliminary Requirement study has been performed for different application requirement.

These requirements are mostly influenced by the optics design. Requirement study is

mostly influenced by satellite class and sub-satellite class like CubeSat’s size, mass

power and transmission budgets constraints.

2.1 Satellite classes definition

2.1.1 Nanosatellite

The term "Nanosatellite" or "Nanosat" is usually applied to the name of an artificial

satellite with a wet mass between 1 and 10 kg (2.2–22 lb). Again designs and proposed

designs of these types usually have multiple Nanosatellites working together or

information (sometimes the term "swarm" is applied). Some designs require a larger

"mother" satellite for communication with ground controllers or for launching and

docking with Nanosatellite [WIKI-SATCLASS]

2.1.2 Picosatellite

Picosatellite or "Picosat" is usually applied to the name of an artificial satellite with a wet

mass between 0.1 and 1 kg (0.22–2.2 lb). Again designs and proposed designs of these

types usually have multiple Picosatellites working together or information (sometimes the

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term "swarm" is applied). Some designs require a larger "mother" satellite for

communication with ground controllers or for launching and docking with Picosatellites.

The CubeSat design, with 1 kg maximum mass, is an example of a large Picosatellite (or

minimum Nanosatellite) [WIKI-SATCLASS].

2.1.3 CubeSat standard

CubeSat standard falls within the class of Picosatellite. It has well defined standardization

and requirements. The CubeSat can be defined as a one unit scalable 1 kg 100 mm x 100

mm x 100 mm cuboids satellite. The standard must conform to the specification as

outline in the documents defined by Calipoly institute. These two requirements mass and

size have impact on the overall system design.

2.2 Minimum requirement in term of satellite class

From the above definition of the standard classes of Picosatellite and Nanosatellite main

design requirement can be inferred. It is assumed that camera must be able to support at

minimum level of its utilization to support CubeSat standard, therefore, a modular

approach has been followed. CubeSat set the target for minimum configuration of the

camera. Two or three structure of three CubeSat structure sized based satellite can be

combined to accommodate for the advanced capabilities of camera to support a larger

optics size and power budgets and better transmission rate.

2.3 Image sizes and data volumes analysis

Wuerzburg ground station contact period for 10 days has been simulated in STK to

provide the ground station visibility and contact period estimates. Altitude of the satellite

is taken as 700km with the ascending node at 10.00 am in sun synchronous orbit. For all

the calculation in the entire report these parameters are used to provide estimated

calculation. Suitable scenario and orbital design for a particular mission needs can only

be define a concrete orbit selected by mission design.

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Simulation is done for minimum elevation of 5[deg]. Maximum access period of the

ground station calculated is around 11[min]. Amount of data generated by image sensor

is in general very large and depends on the resolution or dimensions of the images. Data

volume generated by image sensor is the major problem for their processing,

transmission and storage for on board satellite imaging system with small structure.

Ground station contact periods dictate the imaging parameter.

Figure 2: Würzburg ground station visibility

The amount of data generated though can be reduced by employing compression

techniques. Compression option or solution was not proposed as a hardware solution. For

the design adding compression unit as a separate chip could provide benefit of reducing

data and faster or real time capability to system but add more complexity to the system

hereafter, also require more power budgets. Compression can be used for on-board

system where the transmission of data will be a problem by using offline software

algorithms for compression. But then it will be a slow on-board process.

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One more reason to avoid compression in acquisition chain is to provide processor the

capability to process this data directly. Taking uncompressed data and then

decompressing it for processing will delay the system response time. Offline compression

is proposed for this imager which can makes it suitable for transmission. As an example

Star Sensor TLP detection application requires the non-compressed images in initial

stages for processing.

Normally, it’s up to the application designer to exploit the camera to the maximum

capability, Application designer or operation team of the satellite must find out the

timeline when the processor is idle and thereafter, image compression loop can be started.

Time tags command or mission planning schedules would be useful during space mission

operations for compression. However, it all depends on the application designer to take

maximum output from the mission scenario applicable to particular purpose. Data volume

in bits for the single Image can be calculated by using the following relation.

· · · (2.a)

H = The Image Horizontal Resolution

W = The image Vertical Resolution

B = Number of bits per pixels

N= Number of bands or color channels

Following table outlined some of the Image resolution parameters, keeping in view of the

single channel or only raw Bayer format of 8bit.

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Table 1: Sensor volume calculation and its impact on memory sizing

CIF or QVGA resolution is too low for certain applications and doesn’t provide

reasonable coverage for the aimed application, but these formats are typically useful for

low data rate CubeSats. CubeSats with low transmission like 1200bps can use this

transmission channel but downloading of single image even with QVGA or CIF

resolution will take around 10 to 12 minutes its assumed without error correction over

heads. At best scenario 2 pass of 10 minute would be required to be downloaded at

1200bps. From (Table 2) below it can be noted that data transmission time for 1 image

CIF and QVGA still requires 10 to 11 minute for a single uncompressed image. This still

would not be a solution to transmit at this small bit rate. Offline compression algorithm

on the imaging processor can be exploited for transmission requirement for any mission.

With a ratio of 7:1 for compression the download time will also reduced by the factor of

7 resulting in image download time of 3-4 minutes for CubeSat. However if S-band

transmitter is available or designed for CubeSats at the rate of 512Kbps then it will

provide good support for the image relay to the ground station. It can take few second to

transfer low resolution images as seen from the graph. S-band transmitter for CubeSat at

present has only been designed for some satellite. For e.g. CAN-X 4 & 5 mission triple

CubeSat configuration. Its S-band link provides data rates between 32 and 256 Kbit/s

[CANX 4/5]. Such type of S-band transmitter can be used on triple configuration

CubeSat. Commercial s-band transmitter from other vendor can support larger

transmission rate up to 20Mbits/sec but normally are very expensive.

Sensor Format Data Volume[MB]Data Volume [MB]

10 images

No of Images for

16MB Memory

No of Images for

32MB Memory

No of Images for

64MB Memory

No of Images for

128MB Memory

CIF(352 x 288) 0.097 0.967 165 331 662 1324

QVGA( 320 × 240) 0.073 0.732 218 437 874 1748

VGA 0.293 2.930 55 109 218 437

1M pixel Sensor 1.000 10.000 16 32 64 128

3.2M pixel Sensor 3.200 32.000 5 10 20 40

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pointing, agility and stability requirements.

With regard to optics design following conventional optics design diagram shown in

(Figure 3) have been considered. From the figure focal length and pixel detector size are

related by following relation.

(2.b)

· (2.c)

Where

P = Pixel size or detector Size.

TSD = Sampling distance of the target it specifies the size of the target object that

can be accommodated into the system. With respect to Earth observation

this simply specify the Ground Sampling Distance or GSD

H = Distance of the object from the sensor with regard to Earth observation it’s

the height of the satellite

f = Focal length of the system.

In optics, the f-number (sometimes called focal ratio, f-ratio, or relative aperture) of an

optical system expresses the diameter of the entrance pupil in terms of the focal length of

the lens. In simpler terms, the f-number is the focal length divided by the "effective"

aperture diameter [WIKI-FSTOP].

P a g e | 12


/#

(2.d)

Where

f = focal length of the system

D = diameter of the lens

2.4.1 Pixel size

For the different scenarios related to different applications assessment has been

performed for 6µm x 6µm CMOS sensor with dimension of the imager array size equal

to 640 x 480 pixels. A sensor with smaller pixel size can be selected for some of the

application but there are certain advantages of using a larger pixel size. Pixel area affects

the dynamic range of the system. Larger pixel area allows larger charge capacity and

therefore, provides wider dynamic range. It allows the brighter objects to be clearly more

visible on a darker background. Normally, a wide dynamic range is required for star

sensors. Increasing pixel size increases the S/N ratio and the performance tradeoffs are

generally not acceptable when pixel size drops below 6µm [KODAK]. When the size of

a CMOS imaging sensor array is fixed, the only way to increase sampling density and

spatial resolution is to reduce pixel size. But reducing pixel size reduces the light

sensitivity. Hence, under these constraints, there is a tradeoff between spatial resolution

and light sensitivity. Uncorrelated image noise is visible in sensor images generated by

sensor with small pixel size [FARRELL06]. For the small sensor if the sensor technology

allow to use a smaller pixel size with high dynamic range and higher SNR. Smaller pixel

size, however, requires reduced optical focal length of optics size budgets. We can use

smaller optics for a smaller pixel format sensor.

Following applications analysis has been performed for optics and electronics design.

P a g e | 13


Debris monitoring

Star Sensor for small scale satellite.

Earth observation for small satellites.

Transient lunar phenomenon (TLP) study

Detection of nearby space objects.

2.4.2 Feasibility analysis of Transient Lunar Phenomena

Transient lunar phenomena (TLP) are described as short-lived changes in the brightness

of patches on the face of the Moon. They last anywhere from a few seconds to a few

hours and can grow from less than a few to a hundred kilometers in size. Most instances

of TLP are described as increases in the overall luminosity of a spot on the Moon.

However, sometimes observers report a decrease in a region's brightness or even a change

in its color to red or violet. Reports of TLP have described them as "mists", "clouds",

"volcanoes", among other provocative terms. Even today, they are poorly understood

[TLP]. These TLP require continuous observation of Moon. TLP phenomenon if reported

by astronomers can be verified by satellite based observation or vice versa. Such

detection of change require that the Moon must be imaged continuously, For this thesis

camera has been designed keeping in view of the total duty cycle operation since it is not

possible to observe the Moon continuously using a single satellite a constellation can be

designed to support such observation, or the mission must be planned in a way to support

the maximum utilization and detection. (Figure 4) shows the approximate TLP

observation scenario for Moon observation.

P a g e | 14


Figure 4: TLP observation scenario

2.4.2.1 Impact on electronics

TLP’s require constant observation of the Moon. Since it is not feasible to image the

Moon continuously and transmit all images to the ground so a limit on system is to store

and transmit only the data when these short lived changes are detected. It requires

excessive burden on some image processing on board to detect, the temporal changes in

image also require powerful digital image processing hardware and high end processor

available for image processing. It requires a huge amount of processing on board for

comparison of images continuously like a target tracking mechanism. However,

compromises can be made initially using low end processors. Since the satellite will

always be in motion therefore, it requires some form of image registration before

comparison and time elapsed change between successive images must be detected with

the camera processor.

For observing such phenomenon, the operation duty cycle of the system must be almost

100%. Which provide stressed constraint on power requirements as the system needs to

be operated continuously. However, storage and transmission requirement with this

scheme is not complex as only few amount of image are required for detection so storage

will not be a big concern for this kind of application.

P a g e | 15


A project is in operation at ROBOTIC LUNAR IMAGE Monitor in Cerro Tololo

Interamerican Observatory in Chile and is coordinated by Arlin Crotts, Paul Hickson,

Cameron Hummels & Thomas Pfrommer[TLP]. They have used ground based tracking

system consisting of two camera one low-resolution and high frame-rate with

specification(10km/pixel, 5Hz) and the other high-resolution camera and low frame-rate

with specification (1.2km/pixel, 0.1Hz). This system is constantly taking images of the

Moon, and use image processing algorithm for detecting TLP more sensitively than the

human eye but this system is used for ground based observations. From this we can infer

the extent of image frequency required for processing.

2.4.2.2 Optical feasibility analysis for TLP

Optics parameter for Moon has been elaborated at from 500m/pixel to 10000km per

pixels is shown in the following graph.

Figure 5: Focal length vs. ground sampling distance for Moon

To have a complete circumference of the Moon on a 640 x 480 pixel array of 6µm pixel

size with in the field of view of sensor, we have the focal length ~398.64 mm and field of

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 100000

500

1000

1500

2000

2500

3000

3500

4000

4500

Ground Sampling Distance of Moon[m]

Foc

al L

engt

h[m

m]

Focal Length vs Ground Sampling Distance for Moon TLP

P a g e | 16


view (FOV) of 0.5519 degrees, designing a telescope for this focal length would be a bit

complicated and will be too heavy on structure design, also it doesn’t fit in a CubeSat

with pinhole type camera design. This type of telescope can be accommodated in triple

CubeSat configuration with proper advance design.

For F#=2 focal length vs. aperture has been show for the above calculation with respect

to the sampling distance. The same telescope if used for Earth observation will give the

GSD of 10.558 meters. These numbers are just to give the extent of the design. Same

telescope can be used for acquiring both Earth and Moon images but optics requirements

for such design are quite stringent and challenging and it is difficult to accommodate in

small configuration CubeSat structure. To reduce the optical constraints one preposition

is to use a smaller pixel size. Second proposition is to get a smaller Moon size on the

sensor image plane.

Figure 6: Focal length vs. aperture

0 500 1000 1500 2000 25000

500

1000

1500

2000

2500

3000

3500

4000

4500

Aperture[mm]

Foc

al L

engt

h[m

m]

Focal Lenght vs. Aperture

P a g e | 17


2.4.2.3 Requirement defined for TLP

REQ_TLP_001. Frequency of image for algorithm application can be either 5 to 6 images

per minute. Requirement is inferred from the Ref [TLP]. However this requirement is

difficult to be met without DMA based DSP processor.

REQ_TLP_002. Storage for at least storage of 10 images on reasonable change detection.

REQ_TLP_003. System will not register more than specified amount of images after a

change is detected or system and frequency of image take can be made reconfigurable or

adaptive. (Based on the detection logic and Phenomenon detection scheme)

REQ_TLP_004. Continuous operation must be ensured during the duration of mission in

order not to miss such phenomenon depending on the view of Moon insight in orbit.

REQ_TLP_005. Combination of satellites must be used to monitor different areas of

Moon. Orbits must be defined depending on particular mission requirements.

REQ_TLP_006. Continuous availability and processing of Images for change detection.

REQ_TLP_007. In time processing and storage is required. Image can be transmitted

whenever system will be in contact with ground station.

2.4.3 Earth observation

Small satellite camera on a Pico and Nano satellite provides a valuable resource for Earth

observation.

Figure 7: Camera use as Earth observation scenario

P a g e | 18


Depending on the mission scenario it could be used as a main application of the camera

or the secondary application. Mostly, with other application it can be satisfactorily use as

secondary application. For Earth observation we have the same problem with regard to

telescope design. Following calculation shows the effect of GSD on optical focal length.

The f/# is kept to be f/2 to provide the appropriate focal length to diameter ratio. This

ratio can be used for smaller focal length but for larger focal length, greater f/# must be

chosen to allow for appropriate telescope size. Following calculation has been performed

to show some of the impact on system sizing due to larger focal length.

Figure 8: Focal length vs. Ground Sampling Distance for Earth observation

To have a complete disk of Earth in view of camera of a 640x480 array image plane with

6µm pixel we require FOV of 167.47 degree which is not feasible as wide field of view

make the image inappropriate. A lower FOV must be selected for Earth observation. For

particular mission, the reasonable coverage on Earth must be defined and particular

optics must be selected with support to the other application on-board, With regard to

multiple on-board application of the same device Earth observation can be made

secondary application for the cube sat missions.

100

101

102

103

104

105

0

100

200

300

400

500

600

700

800

900

Ground Sampling Distance(GSD) for Earth observation[m]

Foc

al L

engt

h[m

m]

Focal Length vs Ground Sampling Distance(GSD) for Earth Observation

P a g e | 19


Figure 9: Focal length vs. aperture for Earth observation

2.4.3.1 Requirements with regard to Earth observation

If camera has to support the multiple observations then the Earth observation parameter

can be greatly influence by the added application to the system making the requirement

for the Earth observation a secondary objective. Means that first the system is

parameterized for primary application and then the Earth observation parameter must be

evaluated get the idea of resolution inferred for supporting Earth observation.

2.4.4 Star sensor

Star sensor is used for attitude determination. They provide accurate attitude

determination vectors for satellite. For Star Sensor, the field of view and sensitivity of the

sensor play an important role for the design. Following requirements are inferred.

REQ_STR_001. It must have the capability to store star catalog in flash almost 200KB

minimum is required for the parallel for star sensor algorithm carried out in university of

Würzburg. A larger support for star catalog can be made possible as this requirement

doesn’t conflict with the storage requirement for the system.

0 50 100 150 200 250 300 350 400 4500

100

200

300

400

500

600

700

800

900

Aperture[mm]

Foc

al L

engt

h[m

m]

Focal Lenght vs Aperture for F#=2

P a g e | 20


REQ_STR_002. DSP support will be an advantage for running computation intensive

algorithm.

REQ_STR_003. The dynamic range of the Star Sensor must be limited to stars with a

visual magnitude range MV 2.5 to 6.5 [STEYN]

REQ_STR_004. Star Sensor must have memory to store at least 5 images or greater per

second for image processing.

REQ_STR_005. FOV should be in the range of 7 degrees to 30 degrees. [STEYN]

provide a good ref for selection of reasonable FOV for Sensor. .

SWATH tanFOV deg · π2 · 180

· 2 · H figure 3

(2.e)

Field of view 10 degrees

F# of 1.4

Pixel detector Size = 6µm x 6µm

Using Equation (2.d) For a 10 degree field of view we would require a focal length of

22mm which is affordable for CubeSat based satellite if the mass budget of the complete

satellite permits to allow use of such optics. Moreover, for Star Sensor it is generally

required reasonable size baffle to protect it from stray light. For the secondary application

of earth observation with start sensor system we can get the swath width of 128.48 km

with a ground sampling distance of 191 meters for Earth observation.

2.4.5 Space debris monitoring

Space debris monitoring is another important and challenging candidate for camera on-

board for small satellite. After the launch of first satellite sputnik, many satellites have

been launched into the various orbit of Earth. Most of these satellite and launched

material kept on circulation around the Earth without any control. Many systems,

P a g e | 21


previously launched in space, have been discarded due to non functionality orbital debris

generally refers to material that is on orbit as the result of space missions, but is no longer

serving any function. The launch vehicles or anything which are left in space contribute

to the space debris. They have typically involved the release of items such as separation

bolts, lens caps, momentum flywheels, nuclear reactor cores, clamp bands, auxiliary

motors, launch vehicle fairings, and adapter shrouds. Approximately 70,000 objects

estimated to be 2 cm in size have been observed in the 850-1,000 km altitude band. At

altitudes of 2,000 km and lower, it is generally accepted that the debris population

dominates the natural meteoroid population for object sizes 1 mm and larger [AERO].

Following graph shows the increasing trend in space object.

Figure 10: Earth objects in orbit [NASA-OD]

P a g e | 22


Space debris must be sunlit and the background must be dark in order for the optics to

detect particular kind of debris [UN99]. Optics design does imply to specify the

minimum size to detect debris. 1cm to 10 cm debris size has been used for the assessment

of optics design with respect to the distance of debris from optics or satellite detecting

debris. Distance up to 6km from the satellite orbit has been used for calculating optical

parameter like focal length with respect to space debris distance

Following graph shows the orbital debris focal length for the size of 6µm x 6µm pixel

camera and f/2 f-stop value. The graph compared the distance of object from the satellite

up to 6km using the orbital debris size from 1 to 10cm, acquired by single pixel for a 640

x 480 resolution image plane.

Figure 11: Focal length vs. space debris size

P a g e | 23


2.4.6 Overall requirements

REQ_PRJ_001. The system must support the capability to adapt to particular application

need.

REQ_PRJ_002. Reasonable on board memory should be provided to support more than

one application.

REQ_PRJ_003. Since the various application have different optical need therefore, if the

optical design permit then suitable focal length must be chosen to support multiple

application.

REQ_PRJ_004. The camera should have the ability to support 100% duty cycle.

REQ_PRJ_005. Camera must support power down mode.

REQ_PRJ_006. It must provide interface to support S-Band transmitter data rates.

REQ_PRJ_007. It must be able to receive onboard command using RS232 or CAN base

interface.

REQ_PRJ_008. It must provide acquisition space for minimum of 10 images.

REQ_PRJ_009. It must be as small as possible and weight and power should be saved to

the minimum.

2.4.7 Telescope size

Telescope with larger focal length can be designed compactly. Ideally the telescope sizes

are dictated by focal length. With a single lens design system the length of telescope

would be the same as the focal length however, with multiple bending of light telescope

size can be reduced. Size can be considerably reduced by using the reflective telescope.

Designing or purchasing telescope for size reduction is very costly. Some of work related

to telescope design has been demonstrated by Nano-JASMINE satellite. It has a Ritchey-

Chretien type telescope with a 5-cm effective aperture, a 167-cm focal length and a field

P a g e | 24


of view of 0.5x0.5 degree. The telescope only occupies a volume about 15x12x12 cm,

and weighs two kilograms or less [JASMINE]. This implies the reduction in telescope

length to the factor of 11.13 as compared to focal length.

P a g e | 25


Chapter 3

Previous Work

3.1 Existing satellites with camera

Following explanation summarizes some of the existing CubeSats with camera. The

discussion is with respect to only Picosatellite especially the CubeSats as they specify the

minimum requirements.

3.1.1 CubeSat XI-IV

CubeSat XI-IV was a Pico satellite built by Nakasuka laboratory and is launched in 2003

by Russian rocket “Rockot”, it purpose was to verify commercial off- the shelf

component it has on board camera (Figure 12) below shows the images of earth taken by

CubeSat [PRISM XI-IV].

Figure 12: CubeSat images taken University of Tokyo by CubeSat [PRISM XI-IV]

P a g e | 26


3.1.2 COMPASS-1

COMPASS-1 was a CubeSat developed Aachen University of Applied Science, Germany

and launched on April 28th 2008 [COMPASS-1]. Its purpose is to let take pictures of the

Earth from the unique point of view of a satellite in orbit. It incorporated CMOS Sensor

OV7648FB camera module.

3.1.3 AAU-CubeSat

This satellite launched in 2003 was developed by Danish students of Aalborg University

was launched in 2003. The imaging payload of this satellite consists of a camera which

was developed using the Motorola CMOS sensor MCM20027. This sensor has a

resolution of 1280 x 768. This satellite has used DMA interface [AAU].

3.1.4 CanX-1

CanX-1 is developed by students of the University of Toronto. The objective of CanX-1

is to verify the functionality of several technologies in orbital space. Color and

monochrome CMOS imagers for testing for imaging star fields, the moon, and the Earth.

The objective was to verify the ability to perform star/moon/horizon tracking as part of a

complete attitude determination system [CanX-1].

CanX-1 carries two independent high-resolution CMOS imagers, together with associated

optics and electronics. The purpose of these imagers is to

Validate the use of spaceborne CMOS imagers for science and engineering.

Provide starfield images for the purpose of attitude determination via star- and

Moon tracking, as well as Earth-horizon tracking.

Provide educational images of the Moon and the Earth.

Following two Imagers were used on the system and compression is implemented in

software.

P a g e | 27


Table 3: Imager specifications CanX-1[CanX-1]

Color Monochrome

Model HDCS-2020 ADCS-2120 Quantum Eff. 33% 38% Fill Factor 42% 42% Lens Focal Length 2.1 mm 25 mm Lens Aperture f/2 f/2.5 Diag. FOV 112º 14º Res. @ Nadir 1.5 km/pixel 200 m/pixel Power 200 mW 200 mW

3.2 Existing hardware solutions

3.2.1 C628 enhanced JPEG module

This is a small, lightweight and low power consumption device including most of the

features of a Digital Still Camera (DSC) such as snapshot, video capture, date-time

stamp, file management and others. By using external micro-controller, together with a

well-developed, user-friendly command, people can build a custom made camera for

specific application. Although this can be used for Nanosatellite based application or

triple configuration CubeSat but for Picosatellite range it’s not suitable because of size

and mass budgets. Camera is based on Zoran imaging processor. There are two version of

this processor Zoran coach-6E and 6P imaging processor. This processor can be used for

camera design and is one of the good solution with regard to system design, however,

since in-house camera should be developed to support maximum re-configurability,

therefore, use of BGA packages have been avoided but for camera integrator on satellite

system this processor is one of the best off the shelf solution.

Table 4: C628 enhanced JPEG module specifications [C628]

Image Sensor MegaPixels CMOS sensor Image Processor ZORAN COACH-6E On Board Memory 64Mb Storage Resident 16MB NAND Flash

P a g e | 28


Video Capture 640 × 480 (30 fps) 320 × 240 (30 fps) Unlimited Motion JPEG capturing time depends on available memory space

Photo Resolution

1280 × 960, 640x480 JPEG format

White Balance Normal / Daylight / Tungsten / Floures / Cloudy

UART Baud Rate 115200, 57600 TV out NTSC / PAL USB Interface USB 1.1

Mass storage mode Supported OS: Win2000 / XP / ME

Power DC 5V

Figure 13: Functional diagram C628 module

Compression engine is separate from the acquisition path as shown in (Figure 13) and

therefore, this sensor system seems to more probable candidate in term of available

hardware in the market.

P a g e | 29


3.2.2 C328R Jpeg compression VGA camera module [C328R]

C328R is neat camera which can be purchased with different lenses. These cameras are

controlled by commands send over serial interface, so there are just four cables (Tx, Rx,

+3.3V, Gnd). Communication logic is TTL so additional circuit is required when

connecting to RS-232 port. The best feature on this camera is ability to produce

directly Jpeg images or 'raw' format images in different color depth and sizes. Camera

resolution is VGA so pictures from 80 x 60 to 640 x 480 can be taken.

3.2.2.1 Features

Small in size, 20mm x 28mm

VGA resolution, down sample to QVGA or CIF

3.3V operation

Low power consumption 60mA

User friendly commands to control the module

UART interface of up to 115.2Kbps

Auto detect baud rate and make connection to the host

Power saving mode

Various lens options

Figure 14: C328R Jpeg compression VGA camera module [C328R]

P a g e | 30


This camera would be appropriate for some application like taking images of Earth and

Moon in CubeSat it requires very less power and provide compression support and can be

added to any CubeSat where time critical imaging and faster processing of images is not

required. Following block diagram will give an overview of this camera.

Figure 15: Block diagram C328R camera module [C328R]

3.2.3 C3188A sensor module

The C3188A is a 1/3" color camera module with digital output that uses the

OmniVision OV7620 highly integrated CMOS digital color video camera chip. Digital

video port supplies a continuous 8/16 bit-wide image data stream. All camera functions,

such as exposure, gamma, gain, white balance, color matrix, windowing, are

programmable through I2C interface [C3188A]. This camera module was used on

university of Tokyo CubeSat XI-IV.

Figure 16: C3188A camera module [C3188A]

P a g e | 31


Table 5: C3188A camera module specifications [C3188A]

Imager OV7620, CMOS image sensor Array Size 664 x 492 pixels Pixel size 7.6µm x 7.6 µm Scanning Progressive / interlace Effective image area 4.86mm x 3.64mm Electronic Exposure 500:1 Gamma Correction 128 curve settings S/N Ratio >48dB

Min Illumination 2.5lux @F1.4 Operation Voltage 5 VDC Operation Current 120mW Active 10 µW Standby Lens f6mm, F1.6

3.2.4 OV7648FB camera module

This camera module has OV7648 Camera Chip image sensor with flexible cable

employed in Aachen University of Applied Sciences CubeSat Compass-1 launch on

28.April.2008.

Figure 17: OV7648FB camera module [OV7648FB]

3.2.4.1 Features

Following table outline the features of OV7648FB Camera Module.

P a g e | 32


Table 6: Key specifications OV7648FB camera module [OV7648FB]

Array Size VGA 640 x 480 QVGA 320 x 240

Power Supply Core 2.4V to 2.6V DC I/O 2.25V to 3.6V DC

Power Requirements Active 40 mW Standby 25 μW

Output Formats (8-bit) • YUV/YCbCr 4:2:2 ITU-656 •Raw RGB Data

Lens Size 1/4" Maximum Image Transfer Rate

VGA 30 fps QVGA 60 fps

Min. Illumination (3000K) f1.2 < 1 lux f2.8 < 5 lux

S/N Ratio 46 dB (AGC off, Gamma=1) Dynamic Range > 48 dB (due to 8-bit ADC limitation)

62 db for internal signal Scan Mode Progressive Exposure Time 523 to 1 line period (at selected frame

rate) Gamma Correction 0.45/1.0 Pixel Size 5.6 μm x 5.6 μm Dark Current 30 mV/s Fixed Pattern Noise < 0.03% of VPEAK-TO-PEAK Image Area 3.6 mm x 2.7 mm Package Dimensions 10mm x 9mm x 7.34mm

3.2.5 CMUCAM 3 camera

Another small camera is that can be used for image acquisition and tracking applications

is CMUcam3 hardware platform can be used for acquiring Images it is connected to

LPC2106 ARM7TDMI processor. It is a FIFO based camera which has following

features

CIF resolution (352x288) RGB color sensor

Open source development environment for Windows and Linux

MMC Flash Slot with FAT16 driver support

Four-port Servo Controller

Load Images into Memory at 26 Frames per Second

P a g e | 33


FIFO image buffer for multiple pass hi-res image processing

Figure 18: CMUcam3 block diagram [CMUCAM3]

3.3 Existing optics procurement and design solutions

3.3.1 LENS selection

For the prototype the recommended optics supporting particular sensor format will be

used. However, for particular application needs, optics has to be designed according to

application perspective. Survey on small optics has been done and one manufacturer

Edmond optics has been found supplying micro lenses and optics for camera. Mostly for

different scenario custom optics design and development would be appreciated to satisfy

application needs.

Table 7: Small optical lenses

Focal

Lengt

h

(mm)

Max.

Sensor

Forma

t

f /

#

Angula

r

FOV*

Min.

Workin

g

Distanc

e

Distortio

n @ Full

Field

Max. Res.***

(lp/mm)

A

(mm

)

B

(mm

)

C

(mm

)

D

(mm

)

Mountin

g

Thread On

Axis

0.7

Fiel

d

Full

Fiel

d

1.68 1/4" 2.

5

132.9° 400mm -83.90% 169 80 — 15.0 13.2 3.3 2.8 M12 x

0.5

P a g e | 34


1.7 1/4" 2.

8

109° 400mm -60% 124 87 30 21.0 19.6 4.0 3.2 M12 x

0.5

1.9 1/4" 2.

0

118° 400mm — — — — 17.0 14.5 4.2 4 M12 x

0.5

2.2 1/3" 2.

5

130° 400mm -48.5% 100*

*

63*

*

40*

*

17.0 18.3 4.8 3.7 M12 x

0.5

2.5 1/3" 2.

5

112° 400mm -60% 63 48 30 17.0 20.1 4.6 3.8 M12 x

0.5

2.9 1/3" 2.

0

96° 400mm -36.0% 63 63 40 15.0 18.0 5.2 6.4 M12 x

0.5

3.0 1/3" 2.

0

98.7° 400mm -52.10% 97 62 35 14.0 15.1 5.3 3.9 M12 x

0.5

3.6 1/3" 2.

0

72° 400mm — — — — 14.0 16.1 4.4 4.0 M12 x

0.5

3.9 1/3" 2.

0

74° 400mm -29% 88 54 46 14.0 16.0 5.9 4.0 M12 x

0.5

4.3 1/3" 1.

8

60° 300mm -24.2% 70 50 30 15.0 13.8 3.3 3.3 M12 x

0.5

6.0 1/3" 1.

7

44° 400mm -10% 72 55 46 15.0 15.3 8.0 6.0 M12 x

0.5

6.4 1/3" 2.

4

42.2° 400mm -2.40% 80 63 25 14.8 13.1 5.3 3.3 M12 x

0.5

8.0 1/3" 2.

5

30.9° 800mm <-3.0% 80 63 63 15.0 13.5 5.8 3.0 M12 x

0.5

10.06† 1/2" 2.

8

36° 400mm -0.57% 81 54 64 15.0 13.4 6.1 3.2 M12 x

0.5

10.4† 1/2" 2.

8

35° 400mm -2.00% 93 90 88 14.0 12.0 6.4 4 M12 x

0.5

12.0 1/3" 2.

0

22.3° 800mm -0.15% 63 60 60 14.0 12.0 6.4 4.0 M12 x

0.5

16.0 1/3" 2.

0

17° 400mm -2.50% 75 65 60 14.0 14.4 8 4.5 M12 x

0.5

25.0 1/3" 2.

5

10.7° 200mm -0.46% 83 58 58 25.0 23.5 8.0 6.7 M12 x

0.5

35.0 2/3" 2.

0

17° 200mm -1.10% 160 100 80 25.0 23.4 15.8 16.4 M12 x

0.5

50.0 1/2" 2.

5

6.8° 400mm -1.20% 160 100 80 27.0 48.8 8.0 41.8 M12 x

0.5

Maximum focal length available for this sensor is 50mm. with the largest lens dimension

of 4.8 mm which can be incorporated for the mission. However, these lenses provide

P a g e | 35


standard mount type and a coupling structure need to be developed within the satellite

structure to use these lenses with standard C-mount type adaptor. A larger optics can be

use for Nanosatellite range satellites.

Figure 19: Infinite conjugate micro lenses [EDMUND]

Figure 20: C mount adapter [EDMUND]

3.3.2 Optics design solutions for small size satellite

Optics design is deeply constrained for small satellite and for CubeSat using a larger

optics is infeasible. However, state of the art technology can be developed in this regard.

Performing the survey from the web following two design solutions for optic found quite

appealing. Since the telescope is not designed for the work carried out in this thesis but

the two approaches given below can be used for the system if design budget permit to use

these state of the art technologies.

P a g e | 36


3.3.2.1 Ultra thin telephoto lens

These Ultra thin lenses were developed by researchers at University of California San

Diego (UCSD). They created the ultra thin camera using origami to fold up the telephoto

lens. Imager is around seven times more powerful than a standard lens of the same depth

meaning cameras can now be much thinner and more powerful at the same time

[ALTOFT07].

Ultrathin high-quality image is based on an extension of conventional astronomical

telescopes such as the Cassegrain telescope, with additional folding shown in Figure

below. Light enters the element through an outer annular aperture and is focused by a

series of concentric zone reflectors to the image plane in the central area of the optics.

Figure 21 shows this concept [TREMBLAY07].

.

Figure 21: (a) Conventional lens. (b) Annular folded optics concept [TREMBLAY07]

3.3.2.2 Deployable optics

One of other techniques to reduce the length of the telescope or to be incorporated within

the structure of the Nanosatellite is to use deployable optical concept. This concept was

successfully used in PRISM, which is a remote sensing Nanosatellite. Similar kind of

deployable telescope design can be used on CubeSat Structure. Following image of

PRISM satellite from [PRISM] shows this deployable telescope concept.

P a g e | 37


Figure 22: PRISM satellite deployable optics [PRISM]

P a g e | 38


Chapter 4

Architecture design

4.1 System architecture

There are invariably many designs option on which camera architecture can be based.

One approach is to use shared memory and transfer this data to memory and read this

data by processor, after the images have been stored in the memory following diagram

accessed from [BEYONDLOGIC] summarize this approach. This approach is useful and

can be used in the system however, this approach requires to CPLD or FPGA in the

acquisition chain.

Figure 23: Camera architecture-1 [BEYONDLOGIC]

P a g e | 39


Second approach is to use a FIFO based design as given for [CMUCAM3]. There are

many DSP processors in the market which has these Asynchronous FIFO built into the

chip and can be used for the system. However, due to the ease of using ARM processor,

and to avoid costly solution, DSP approach is avoided for this design. TI and Analog

devices DSP offer the performance solution in term of processing power and can be used

for Nanosatellite. DSP based imaging processors are expensive in term overall

development cost and require more development time than conventional processor.

One more important design aspect is to use FPGA, and built the whole design in single

chip, a single chip design approach is the best approach. However, due to the same

reasons as outlined for DSP above this design approach has been avoided. For

architecture following is proposed based on the above discussion. The selected

architecture reasonably provide the good margin for faster image acquisition and suitable

for many applications.

This camera prototype is designed to support Picosatellite and Nanosatellite applications.

Function of the imaging system is to support the different application, provide storage

capability for the system and provide interface for the OBC and transceiver. Mostly for

Nanosatellite launch cost is much greater then Picosatellite or CubeSat standard so

reliability is the most important factor for such class of satellite. Failure of payload or any

component on such class of satellite is unavoidable. However, CubeSat standard satellites

normally rely on non-space rated Commercial-Off-The-Shelf (COTS) components.

Reliability is an issue but small size doesn’t permit the use of redundant hardware mostly

due to power requirements which is indirectly related to mass budget. Triple

configuration CubeSat provides the use of a bit larger components if desired.

P a g e | 40


Figure 24: Proposed system architecture-2

Application like Star Sensor and Debris monitoring and TLP are mostly driving the

system design for the processing part and other application like Remote Earth

Observation and others require long time memory storage. For this camera, design is

P a g e | 41


based my on architecture similar to one of the Star Sensor design proposed in the paper

[STEYN] and [CMUCAM3] but with innovative DMA based solution. This design has

more flexibility many component can be re configured for particular application needs

also it provide more flexibility for larger design. Mostly, cameras for commercial use and

mobile phones also follow similar kind of design approaches, and are based on high end

DSP and imaging processors.

Many cameras which require a single shot can only manage one intermediate buffer

memory as a FIFO similar to equal to the size of image to store. A single image buffering

allows transfer of this image to the ground station at later stages. Camera design approach

is kept as modular, meaning that the sensor and FIFO will be designed on single PCB and

processing board with storage element will be constructed on other board. For CubeSats

if it’s only desired to take snapshots then the camera sensor board with FIFO can be

directly interfaced to OBC I/O’s. This offer saving in term of power budgets and

formulate it use feasible on satellite like CubeSat. The architecture is normally easy to

implement and can be used for application like snapshot of Earth. CubeSats transmission

rate are normally not feasible to download in a single pass or without compression.

Compression unit as a separate solution is not proposed, however, offline processing can

be done onboard to transfer images to ground station. This discussed approach is feasible

when simultaneous multiple images are not required in performing any calculation on

board on images. Following section discuss the components selection criteria for the

system on which the component have been selected and henceforth, provides the detail

feature and discussion for selected component.

4.2 Sensor

4.2.1 CCD Vs CMOS

System Dynamic Range: Dynamic Range (DR) is the ratio of the maximum output signal,

or saturation level, of an image sensor to the dark noise level or minimum level of the

P a g e | 42


imager [KODAK SENSOR]. CCD sensors are better in term of dynamic range

[LITWILLER].

DR 20. logVV

(4.a)

Responsivity: The imager output voltage per incident optical energy density is called the

imager responsivity, and it is expressed in volts per micro-joule per centimeter squared,

or V/ (J/cm2) [KODAK SENSOR]. Both technologies are more or less similar in term of

responsivity. CMOS imagers are marginally superior to CCD as gain elements can be

placed and integrated on the chip [LITWILLER].

Reliability: Both technologies are more or less comparable in term of reliability.

Power: CMOS sensors consume less power than similar CCD sensors. Also for CMOS

sensor a single supply at the chip interface provide additive advantage over CCD.

Size: CMOS has the advantage to provide higher system integration. Many components

are integrated on the sensor chip. This means there are some DSP processing block and

A/D converters as well as programming interface for windowing operation available in

chip.

Speed: CMOS arguably has the advantage over CCDs because all camera functions can

be placed on the image sensor. With one die, signal and power trace distances can be

shorter, with less inductance, capacitance and propagation delays. To date, though,

CMOS imagers have established only modest advantages in this regard, largely because

of early focus on consumer applications that do not demand notably high speeds

compared with the CCD’s industrial, scientific and medical applications [LITWILLER].

Blooming: Overflow of photo-generated charge is termed blooming. The result of

blooming is a corrupted image near the blooming site. The extent of the image

degradation is dependent on the level of excess charge and on the architecture of the

P a g e | 43


imager being used [KODAK SENSOR]. CMOS has natural antiblooming immunity to

counter blooming. CCD require some specific engineering to achieve such structure,

however this can be built-in on chip, but consumer grade CCD have mostly lacks anti-

blooming structures [LITWILLER].

Windowing: One unique capability of CMOS sensor is the windowing. The portion or

window of image can be read which provide additional advantage of reduced size images

or preview before being download or region of interest kind of operation. CCD sensor

has minimal support for windowing [LITWILLER].

Biasing and clocking: CCD requires some extra hardware for clock generation and some

external clock drivers for impedance matching. This requires clock generation hardware

for several CCD phase clock in term of PLDs or CPLDs. With CMOS no such clocking

hardware is required and mostly the clocking and synchronizing components are built in

to the system, therefore, CMOS provide a better solution in term of complexity of system

design [LITWILLER].

With the above discussion use of CCD sensor has been ruled out, and it has been decided

to use CMOS sensor for application. Star Sensors have already been built for space using

CMOS sensor which is one of the applications proposed for the project. In any case

system in which absolute calibration is must and uniformity of sensor pixels plays

important role care must be taken and calibration and correction techniques should be

performed. For the Star Sensor dynamic range and S/N ratio is of most important

concern.

4.3 Available CMOS sensors survey and selection

Market survey of available sensor has been performed. There are many sensors available

in market. A complete and thorough survey of uncountable sensor is infeasible. Sensors

used in some of the CubeSats mission provide some direction toward the selection. One

of the problems in finding some of the sensor is that no complete data sheets (only

P a g e | 44


preliminary information) are available for evaluation purposes also there are other legal

issue involved. These all factor greatly influence the project completion time. Following

table outline some of the sensors in term of availability. Most appropriated moderate

candidate has been selected from the table keeping in view of also the availability, power,

and pixel size and windowing operation and availability. Since a larger pixel size was

desirable OV7720 6µm x 6µm for the sensor to be useful for Star Sensor or debris

monitoring application was selected from the table below. However, big pixel size sensor

consumes a little more power. It adds up to 40 mW to 50 mW to the whole system. This

increased figure is practically feasible.

Table 8: Selected sensor comparison

Sensor Provide

r

Resol

ution

Lower

Resolut

ion

support

Powe

r

[mW

]

Built

-in

ADC

ADC

Width

Output

Format

Temp

[ºC]

Dynamic

Range

[dB]

Pi

x

Si

ze

Packag

e

LUPA-1300 Cypres

s

1280 x

1024

Yes 900 No N

A

Analog 0 to 60 --- 14 μm

x 14

μm

--

CYIWOSC

1300AA

Cypres

s

1297H x

1041V)

Yes TBA Ye

s

10 Bayer-

pattern

0 to

+60°C

TB

A

2.8um

x

2.8um

--

MCM20027 Motoro

la

1280 x

1024

Yes 250 Ye

s

10 Bayer-

pattern

0-40 50

dB

6µm x

6µm

--

OV9655-

V28A

OmniV

ision

1280 x

1024

SXGA

Yes 90 Raw

RGB,

RGB

(GRB

RGB56),(

YUV

YCbCr)

0°C to

50°C

-- 3.18

μm x

3.18u

m

CSP

-28

OV7610(No

t Produced)

OmniV

ision

640 x 480 Yes 200 Ye

s

8/

16

bit

Raw RGB

Data,

RGB,

YUV

wi

de

8.4μm

x

8.4μm

P a g e | 45


OV9665-

V26A

OmniV

ision

1280 x

1024

SXGA

Yes 80 Ye

s

10 Raw RGB

Data,

RGB,

YUV

-30 to +70 wi

de

2μm

x2μm

26-

pin

CSP

2

OV7720-

V28A

OmniV

ision

and below,

CIF,

QVGA,

VGA

Yes 120 Ye

s

10 Raw RGB

Data,

RGB,

YUV

–20 to +70 60

dB

6.0µm

x

6.0µm

CSP

-28

OV7710-

C48A

OmniV

ision

and below,

CIF,

QVGA,

VGA

Yes 140 Ye

s

10 Raw RGB

Data,

RGB,

YUV

-40 to

+105

wi

de

6.0µm

x

6.0µm

CL

CC-

48

OV7725-

V28A

OmniV

ision

and below,

CIF,

QVGA,

VGA

Yes 120 Ye

s

10 Raw RGB

Data,

RGB,

YUV

–20 to +70 60

dB

6.0µm

x

6.0µm

CSP

-28

OV7211-

F48V ™

OmniV

ision

VGA -- 140 Ye

s

10 RGB,

YUV

–20 to +70 wi

de

6.0µm

x

6.0µm

28-

pin

CSP

OV07710-

C00A

OmniV

ision

VGA -- 140m

W

Ye

s

10 10bit raw

8bit RGB,

YUV

-40 to

+105.

53

dB

6.0µm

x

6.0µm

CL

CC-

48

4.4 Sensor features

OV7720 from OmniVision sensor selected as a final candidate from (Table 8) because of

following additional features.

1. 6µm x 6µm pixel size.

2. 8 bit raw data format is available.

3. CLCC package was available which is easy for prototyping at low cost.

4. Provide SCCB interface to program and control many of the important sensor

features.

5. Automatic image control functions including:

Automatic Exposure Control (AEC)

P a g e | 46


Automatic Gain Control (AGC)

Automatic White Balance (AWB)

Automatic Band Filter (ABF)

Automatic Black-Level Calibration (ABLC) This sensor is also chosen as

minimum amount of support component are needed.

6. It provides the full functionality of a single chip camera. A/D converters are built

into the chip and sensor provides the digital interface for easy integration in to

digital systems.

7. Availability and purchase issues.

8. Provide configuration supports for image sizes. VGA, QVGA, and any other size

scaling down from CIF to 40 x 30.

9. High sensitivity for low-light operation

10. Provide reasonably good dynamic range and SNR

Figure 25: Sensor OV7720

P a g e | 47


4.4.1 Block diagram of the sensor OV7720

Figure 26: Internal block diagram sensor

Here sensor provides the 10 bit output on digital interface. Sensor is a ten bit sensor but

only upper 8 bits are used for the design. Data from the image array unit is sampled by

A/D converter and is passed through processing stages and finally available at output

D[9:0]. SCCB block here provide the programming interface to control the sensor

parameters. Video timing generator block provide the timing and synchronization signal

for the acquisition unit and is very useful for software synchronization through interrupts.

4.4.2 Sensor parameters

Following are the important parameters for this sensor.

P a g e | 48


Table 9: OV7720 sensor parameters [OV7720]

Array Size 640 x 480

Power(Active) 120 mW typical maximum( Depends on the

image acquisition rate)

Output Format support for:

– Raw RGB(10/8 bit)

– RGB (GRB 4:2:2, RGB565/555/

444)

– YCbCr (4:2:2) formats

Maximum Image Transfer Rate 60 fps

Sensitivity 3V/(lux.sec)

SNR 50 dB

Dynamic Range 60 dB

Pixel Size 6µm x 6µm

Scan Mode Progressive

Dark Current 40mV/s

Image area 3984µm x 2592µm

Package dimension 1.143 cm X 1.143 cm

automatic image control functions

including:

– Automatic Exposure Control (AEC)

– Automatic Gain Control (AGC)

– Automatic White Balance (AWB)

– Automatic Band Filter (ABF)

– Automatic Black-Level

Calibration (ABLC)

image quality controls including

Image Window Sizes supports image sizes: VGA, QVGA,

and any size scaling down from CIF

to 40 x 30

Operating Temperature Range -20°C to +70°C

Digital Signal Processor Block Color saturation, hue, gamma,

P a g e | 49


sharpness (edge enhancement),

and anti blooming

Elimination of Color Cross talk

Dynamic Range Consult [OV7720]

SNR Consult [OV7720]

4.4.3 Camera SCCB interface for configuration

4.4.4 Prototype optics for sensor

With respect to current testing in the system a compatible lens with following

specification with following parameter was used. Refer to Annex-4 for detail mechanical

specifications.

Part# 741R

Effective Focal Length (EFL) = 5.3 mm

F#= 1.9 mm Infinity

Angle of View = 55.6 deg Diagonal

45.7 deg Horizontal

35.1 deg Vertical

4.5 Processor market survey

If we want improve processing speed, we must first understand what it spends its time

doing. It is a common misconception that computers spend their time computing, that is,

carrying out arithmetic operations on user data. In practice they spend very little time

'computing' in this sense. Although they do a fair amount of arithmetic, most of this is

with addresses in order to locate the relevant data items and program routines. Then,

having found the user's data, most of the work is in moving it around rather than

processing it in any transformational sense [FURBER]

O

pr

pr

pr

in

u

A

d

ex

One of the pr

rocessing al

rocessing o

rocessors tak

nstructions. B

sed for imag

A market sur

etails of the

xternal mem

1. It mus

2. It mus

3. It mus

4. Intern

extern

Figure 27

rocessor sel

lgorithm are

of images. F

kes 43% of

Both data m

ge processing

rvey of the

e candidate

mory interfac

st have exter

st provide U

st have DMA

nal video FI

nal video FIF

Instr

Data Move

Compariso

Kashif G

7 Typical dy

ection criter

e data inten

From (Figu

the time. Se

movement ins

g algorithms

processor h

processors

ce has been s

rnal memory

UART/CAN b

A architectur

IFO can be

FO.

15%

13%

uction T

ement

on

Gulzar, MSc D

ynamic instru

ria is to use

nsive, a lot

ure 27) clea

econd time c

struction and

s.

has been per

parameters.

selected due

y interface.

based interfa

re to support

an advanta

23%

%

5% 1%

Type vs D

Control flow

Logical operat

Dissertation

uction usage

a DMA bas

of data mo

arly the dat

consuming in

d control flo

rformed. Ta

LPC2468

to following

ace for OBC

t memory in

age however

43%

Dynamic

Arth

ions Othe

e [FURBER]

sed processo

ovement is

ta movemen

nstruction is

w instructio

able in Anne

DMA based

g reasons.

C.

ntensive proc

r design pe

c Usage

hmetic operatio

er

P a g e

]

or. Mostly im

required fo

nt instructio

s the control

on are extens

ex-A provid

d processor

cesses.

rmits the u

ons

e | 50

mage

or the

on in

flow

sively

de the

with

se of

P a g e | 51


5. USB interface and debugging hardware like JTAG or ISP may provide additive

advantage for application development processor.

6. On board RTC can provide time based synchronization and time tagging of image

however these function can also be controlled by OBC.

4.5.1 Selected processor features

A detail analysis of imaging processor was carried out to in term of function supported.

ARM based architecture was chosen for the application and a survey is performed on the

available ARM based processor attached in Annex-1. This table outlines the various

candidates selected for the hardware. Many of the COTS based components used in

mobile industry are very small where these IC packages are based on BGA packages

requiring excessive amount of work in term of hardware development and testing. For

these type of processor component soldering requires special equipment also inspection

for defect require X-raying techniques. One possible solution for development is to

design the system and outsource the development process but it require excessive amount

of budget.

Suitable COTS based component in term of processing have been outlined in the

following section. Power Specification of LPC2468 has not been mention specifically in

the data sheet but it can go up to maximum of 1.5 Watt based on heat dissipation values

which seems to be very large for single CubeSats, however, for multiple configured

CubeSat this power is within the power budgets. Moreover, power mentioned is based on

absolute maximum rating. Since the hardware has feature to turn off power to most of the

unused peripherals, power can be greatly reduced further buy turning off the processor

unused peripherals. Although BGA package of the device is available that can reduce the

PCB size to very minimum but for the sake of simplicity and development on the pre-

specified schedule this package use was avoided. The architecture of the processor is

shown below.

P a g e | 52


Figure 28: Processor architecture [LPC2468]

The following processor features are considered for this camera design [LPC2468]

512 KB on-chip flash program memory with In-System Programming (ISP) and

In-Application Programming (IAP) capabilities. Flash program memory is on the

ARM local bus for high performance CPU access.

64 KB of SRAM on the ARM local bus for high performance CPU access.

P a g e | 53


Dual Advanced High-performance Bus (AHB) system allows simultaneous

Ethernet DMA, USB DMA, and program execution from on-chip Flash with no

contention.

EMC or external memory controller provides support for asynchronous static

memory devices such as RAM, ROM and Flash, as well as dynamic memories

such as Single Data Rate SDRAM also the camera is interfaced to this EMC

block.

General Purpose AHB DMA controller (GPDMA) that can be used with the SSP,

I2S, and SD/MM interface as well as for memory-to-memory transfers.

CAN controller with two channels.

SPI controller.

Three I2C-bus interfaces (one with open-drain and two with standard port pins).

SD/MMC memory card interface.

Real-Time Clock (RTC) with separate power domain, clock source can be the

RTC oscillator or the APB clock.

Watchdog Timer (WDT). The WDT can be clocked from the internal RC

oscillator, the RTC oscillator, or the APB clock.

Boundary scans for simplified board testing.

Four reduced power modes: idle, sleep, power-down, and deep power-down.

Four external interrupt inputs configurable as edge/level sensitive. All pins on

PORT0 and PORT2 can be used as edge sensitive interrupt sources.

From the table in Annex-1, there are some of the hardware available which provide front

end video ports for direct interface to the sensor since they were only available in BGA

package therefore there use is avoided. OMAP3515 from TI has been used for developing

mobile phone based system which is best for power and other specification and can be

used as a digital signal processing hardware with support for faster algorithm execution.

If overall budget permits then this can be used efficiently for many of the task on board

P a g e | 54


with support for DSP operation for CubeSat mission. But DSP based processor is a costly

solution compared to ARM processor both in term of development and project schedule.

Following discussion outline gives the description of different features of the processors

considered for this Hardware Design. These featured functions are referred from ref.

[LPC2468].

4.5.1.1 External memory controller

The LPC2468 EMC is an ARM PrimeCell MultiPort Memory Controller peripheral is

supported for asynchronous static memory devices like RAM, ROM, and Flash. In

addition, it can be used as an interface with off-chip memory-mapped devices and

peripherals. Sensor is also interfaced to this EMC bus to exploit DMA function. The

EMC is based on an Advanced Microcontroller Bus Architecture (AMBA) compliant

peripheral.

4.5.1.2 General purpose DMA controller

The GPDMA is based on AMBA AHB compliant peripheral which allow different

peripherals to have DMA support. The GPDMA allows peripheral-to-memory, memory-

to-peripheral, peripheral-to-peripheral, and memory-to-memory transactions. DMA

provides unidirectional serial DMA transfers for a single source and destination. The

source and destination areas can be accessed through the AHB master interface.

4.5.1.3 USB interface

The Universal Serial Bus (USB), a 4-wire bus which supports communication between a

host and one or more (up to 127) peripherals. The host controller allocates the USB

bandwidth to attached devices through a token-based protocol. The bus supports hot

plugging and dynamic configuration of the devices. All transactions are initiated by the

host controller. LPC2468 provides fully support compliant USB 2.0 specification (@full

speed).

P a g e | 55


4.5.1.4 CAN controller

The Controller Area Network (CAN) is a serial communications protocol which

efficiently supports distributed real-time control with a very high level of security. This

communication protocol is available on many satellites and provides a very robust

interface. The CAN block is intended to carry multiple CAN buses at the same time,

allowing the device to be used as a gateway, switch, or router between two of CAN buses

in industrial or automotive and space applications.

4.5.1.5 UARTs

The LPC2468 contains four UARTs. The UARTs include a fractional baud rate

generator. Standard baud rates such as 115200 can be achieved and is used for the test

application command, control and accusation interface.

4.5.1.6 SPI Interface

The LPC2468 contains one SPI controller. SPI is a full duplex serial interface designed to

handle multiple masters and slaves connected to a given bus. Only a single master and a

single slave can communicate on the interface during a given data transfer. During data

transfer the master always sends 8 bits to 16 bits of data to the slave, and the slave always

sends 8 bits to 16 bits of data to the master

The peripheral clock that is normally used for peripherals can be derived from CPU clock

and it can run with the same max speed as ARM7 AHB at 60MHz (max). From the data

sheet it can be inferred that we can divide this with a factor of 8 or greater and SPI rate

can be calculated as 1/8 of input peripheral clock.

Maximum SPI ratPCLKSPCCR

minimum 8 (6.a)

This implies

P a g e | 56


PCLK = 60MHz.

608

7.5

200 (1.a)

Since data can be transferred to S-Band transceiver around this rate therefore, is

supported by capability of S-Band Transmitter and hence can be safely used for this

purpose. It depends only on the implementation of S-Band Transceiver implementation.

4.6 FIFO for image buffering

After the processor and sensor has been selected for the proposed architecture, remaining

important hardware component is FIFO. There are two types of FIFO available one is

asynchronous FIFO which has multiple clock domains means support separate clock for

read and write operation. Second type of FIFO is synchronous FIFO which has only

single clock domain for read and write operation.

Asynchronous FIFO is only investigated due to due to the consideration for multiple

clock domains. Sensor can write the data onto the port of FIFO at its pixel clock rate and

processor can read the FIFO at its memory or port access rate. CMOS sensor can be

easily interfaced to asynchronous FIFO.

Following FIFOs were available from Averlogic and Cypress semiconductor for present

512 KB FIFO from the Averlogic AL440 was selected as it can store easily 640 x 480

size image. Sensor board with single FIFO can be used with direct interface to on board

processor.

P a g e | 57


Table 10: FIFO for image acquisition selection table

Product

Descriptio

n

Configuratio

n

Application Part No. Power

Specifications

Speed Package

Full HD

FIFO

memory

8M X 16 bits Multimedia

System,

Video

Capture

System, and

various video

data buffering

AL460A 3.3

2.5V

150/75

MHz

LQFP12

8

Frame

FIFO

512K X8 bits Serial I/O

Buffer,

HDTV,

Multimedia

System

AL440B 3.3V

52 mA

171.6 mW

40/80

MHz

44-

TSOP(II)

Frame

FIFO

384K X8 bits Serial I/O

Buffer, NTSC

Video,

Multimedia

System

AL422B 3.3V

5V

45mA@30MHz,3.3

V

148.5 mW

50

MHz

28-SOP

FIFO

Cypress

512K X9bits Asynchronou

s first-in first-

out (FIFO)

buffer

CY7C421

-15AC

5V

55 mA@40 Mhz

275 mW@40 Mhz

40Mh

z

32

TPQFP

4.6.1 Al440B description

The AL440B 4Mbits (512k x 8-bit) FIFO memory provides completely independent 8bit

input and output ports it can operate at a maximum speed of 80 MHz as seen from table.

The built-in address and pointer control circuits provide a very easy-to-use memory

P a g e | 58


interface that greatly reduces design time and effort [AVERLOGIC]. Following block

diagram explains the internal working of FIFO.

Figure 29: AL440B internal block diagram [AVERLOGIC]

4.6.2 FIFO features [AVERLOGIC]

4Mbits (512k x 8 bits) organization FIFO

Independent 8bit read/write port operations (different read/write data rates

acceptable)

Maximum Read/write cycle time: 80 MHz and 40 MHz (2 speed grades)

Input Enable (write mask) / Output Enable (data skipping) control

Window read/write with Mirroring capable

Selectable control signal polarity

Input Ready / Output Ready flags

Direct cascade connection

Self refresh

3.3V 10% power supply

P a g e | 59


Following system design has been proposed. Selected components have been shown to

elaborate this system block diagram.

4.7 System block diagram based on selected components

In the system block diagram in (Figure 30) shown below a part from processor, sensor

and FIFO, many other options are set as optional and if particular application or group of

application demand storage and processing capability these option can be use.

Figure 30: System block diagram

P a g e | 60


There is one optional interface to SDRAM left kept as a template in PCB design and

could be added for particular mission if the power budget permits. SDRAM chip requires

constant power and cannot be used as a permanent storage for long time and must be

turned on and off during the whole cycle of the missions. It should be used only for

processing temporary images. For permanent storage a flash based solution is the best

and can be used after the onboard processing has been done to store images which does

not require processing and only need to be later transmission to ground station.

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Chapter 5

Schematic design

Schematic for the processor board has been designed by consulting the development

board Schematic from Olimex LPC2468 development Board [LPC-E2468] and IAR Kit

development board [IAR] schematics have been attached in Annex-2 for processor board

Annex-3 for sensor board. The camera consists of two PCB modules. One module

contain sensor, FIFO buffer, and other module consists of processor with supporting

memories debug and output interfaces.

5.1 Sensor interface with FIFO

Figure show the interface between the processor and sensor.

Figure 31: Interfacing between sensor and FIFO

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Following signal were present at the FIFO write Interface

Table 11: FIFO write interface signals

Pin Name Pin

Number

I/O Type Description

DI[7:0] 9,8,7,6,4,3,2

,

1

I The DI pins input 8bits of data. Data input

is Synchronized with the WCK clock.

Data is acquired at the rising edge of

WCK clock.

WE 10 I WE is an input signal that controls the 8bit

input data write and write pointer

operation.

IE 11 I IE is an input signal that controls the

enabling/ Disabling of the 8bit data input

pins. The internal write address pointer is

always incremented at rising edge of

WCK by enabling WE regardless of the IE

level.

WCK 13 I WCK is the write clock input pin. The

write data input is synchronized with this

clock.

WRST 14 I The WRST is a reset input signal that

resets the write address pointer to 0.

IRDY 15 O IRDY is a status output flag that reports

the FIFO space availability.

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FIFO read interface contains the following signals.

Table 12: FIFO read interface signals

Pin name Pin

Number

I/O

Type

Description

DO[7:0] 36,37,38,39,

41,42,43,44

O The DO pins output 8bit of data. Data

output is synchronized with the RCK

clock. Data is output at the rising edge of

the RCK clock.

RE 35 I RE is an input signal that controls the 8bit

output data read and read pointer

operation.

OE 34 I OE is an input signal that controls the

enabling/ disabling of the 8bit data output

pins. The internal read address pointer is

always incremented at rising edge of RCK

by enabling RE regardless of the OE level.

RCK 32 I RCK is the read clock input pin. The read

data output is synchronized with this

clock.

RRST 31 I The RRST is a reset input signal that

resets the read address pointer to 0.

ORDY 30 O ORDY is a status output flag that reports

the FIFO data availability.

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Following signals were present in the connector for interfacing with the processor board.

The FIFO block design has been given as a reference in FIFO data sheet [AVERLOGIC]

for interfacing.

Figure 32: Connector for FIFO interfacing with processor board

Table 13: Processor board connector signals description

Pin name Pin Function I/O Signal Description

FD0…. FD7 The DO pins

output 8bit of

data.

WRST Resets the Write Address Pointer

3.3V Supply 3.3V

10%.

WE_ENA

Gnd Ground FRAME Frame Synchronization from sensor

Rrst PWDN Sensor Power Down Mode Select

IRDY ORDY

RESET_SEN automatically

Initialize

SDA_FIFO SDA carries the serial bus read/write data

bits.

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sensor and

FIFO chip

logic.

CS_SEN Chip select

Signal from

Processor

OE_RCK Output Rd Signal from Processor

SCL_FIFO SCL supplies

the serial bus

clock signal

to FIFO.

SDA,SDL Provide Serial Interface for Sensor

operation.

Note both serial interfaces can be made common through jumper configurations TPC1

and TPC2 shown in schematics.

5.2 Serial bus interface to FIFO

The Serial bus interface consists of the SCL (serial clock), SDA (serial data) and

/SDAEN (serial Interface enable) signals. There are pulling up circuit internally for both

SCL and SDA pins. When/SDAEN is high, the serial bus interface is disabled and both

SCL and SDA pins are pulled high. When /SDAEN is low, the serial bus interface is

enabled and data can be written into or read from theAL440B register set. For both read

and write, each byte is transferred MSB first and LSB last, and the SDA data bit is valid

when the SCL is pulled high [AVERLOGIC]. Timing relation is shown in the following

(Figure 33-34). Serial interface contain many command and will be discussed in the

software section for the project.

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Figure 33: AL440B Serial bus write timing

Figure 34: AL440B Serial Bus read timing

5.2.1 Interface connection of sensor board with processor.

Figure 35: Sensor board connector pin out

Signal Description Signal Description

D0…. D7 Connect to Data Bus WRST Connect to P2.4 IO

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3.3V Supply 3.3V to sensor

board

WE_ENA Connect to Onboard

IO Pin P2.0

Gnd Ground FRAME Frame

Synchronization from

sensor connect with

processor P2.13 and

act as an interrupt

signal

RRST P2.2 System Reset

Signal

PWDN Sensor Power Down

Mode Select connect

to P2.1

IRDY Read Reset connect to

P2.3

ORDY Reports FIFO

availability

P2.13.

RESET_SEN automatically

Initialize sensor and

FIFO chip logic.

SDA_FIFO SDA carries the serial

bus read/write data

bits.

CS_SEN Chip select Signal

from Processor

connected to CS0

OE_RCK Output Rd Signal from

Processor

SCL_FIFO SCL supplies the

serial bus clock signal

to FIFO. Connected to

processor I2C Bus

SDA,SDL Provide Serial

Interface for Sensor

operation.

. Connected to

processor I2C Bus

5.3 Sensor read operation

For the software programming and acquisition scheme the start of the VSYNC frame

generate interrupt and next start of frame generate interrupt these interrupt must be

counted between frame and sensor must be read before the next available frame is

available. We can start reading the image as soon as we get frame interrupt and empty the

P a g e | 68


buffer of specified. With the DMA we can then store this data to available 16MB

SDRAM. As soon as all the images for particular application are stored in the SDRAM

processing algorithm can be started. If no processing is required the sensor can be stored

on the flash for later transmission to ground station.

The problem with utilizing storage on SDRAM is that it consumes much power and must

be turned off when there is no onboard processing however, for continuous duty cycle

application it cannot be turned off. But nevertheless storage on flash provide a better

solution in term of power saving. For CubeSat solution use of SDRAM is not

recommended. For the test application SDRAM is not used.

Figure 36: Interrupt latency for VSYNC or frame pulse

5.4 SCCB programming

Sensor has provided an SCCB interface for programming, which can directly be

interfaced to I2C. The programming protocol for two wires SCCB is quite similar to I2C.

However, there are certain difference i.e. the sensor Acknowledgement bit is don’t care

and it’s only based on three kind of transactions

3-phase write transaction cycle

2-phase write transaction cycle

2-phase read transaction cycle

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Phase is composed of 9 bits 8th data bits followed by 1 don’t care bit which is usually an

acknowledgement bit in I2C interface. Following figure illustrated different phases of

programming sensor registers.

Figure 37: Sensor register programming logic through SCCB using I2C[SCCB]

Phase 1: ID_Address

Phase 2: Sub_Address

Phase 3: Write Data

5.5 Memory

Up to 16MB SDRAM and 128MB Flash memory interface has been provided and

interfaced with the system this option is left configurable different memory sizes can be

used. However, if for low level mission where only picture acquisition is of important

concern and not and not the processing SDRAM use can then be avoided to save large

amount of power. Memory interface are typical design followed for the SDRAM or

FLASH and can be referred in schematics given in Appendix 2.

5.6 CAN/RS232 Interface

TJA1050 is used as the CAN transceiver. Which can provide interface for OBC operation

on can based network. Can termination resistor are provided for this system. RS232

Interface is also provided to support programming operation, testing of command and

control operation and image transmission through USB based serial cable.

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5.7 Debugging interface and processor clocking

12 MHz crystal is used as a main clock source. This clock source with the help of on

board PLL can be multiplied and then divided to obtain the processor operation clock.

Crystal Y2 provides the on board RTC clock. On board debugging and programming can

be performed using the JTAG interface. This connector of JTAG has been routed to P2

connector. Olimex OCD USB JTAG Debugger is used for programming and debugging.

Following figure outlines the corresponding JTAG interfacing. JTAG interface has been

provided for adding debugging capabilities to the system. This debugging interface can

be removed for flight hardware to save on board mass and space.

Figure 38: Debugging interface logic

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5.8 Power supply

The system is operated from 5V supply which was further regulated down to 3.3 volts for

sensor and processor and for other components on PCB. For prototype schematic system

regulation support 1.6 Watts. However, direct system voltage of 3.3V from the regulated

power bus in the satellite can support more power in that case regulator can be bypassed.

5.9 Power budgets and alternatives

Following table indicate the major component drawing system power.

Table 14: Power configuration with now optional component removed

(Typically proposed for Nanosatellite Class)

Component Power[mW]

OV7720 120

FIFO 171.6

Processor 1500 max

SDRAM

IS42S16800D

1000

FLASH

K9F2808Q0C 128MX8

OR

HY27UF081G2M 16MX8

33

UART Chip 0.99

Total 2825.59

Table 15: For CubeSat with sensor board directly interface with OBC(Alternative-1)

Component Power[mW]

OV7720 120

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FIFO 171.6

Total 291.6

Table 16: For CubeSat allowing the use of power up to 1 W*

Component Power[mW]

OV7720 120

FIFO 171.6

Processor (Processor can operate on power less then 500m

with many peripheral turned off)*

1500 max

FLASH

K9F2808Q0C

128MX8

HY27UF081G2M

16MX8

33

UART Chip 0.99

Total 1825.59

Above (Tables 14-16) highlight the power budget calculations. Since many of the feature

can be made configurable for particular mission. If the power budget doesn’t permit to

use full configuration of the system power can be compromised on lower functionality.

Alternatives one and two can be used depending on the power budgets for CubeSat.

Typically CubeSats have 2-10 Watts of power budgets for complete satellite.

5.10 Mass budgets

For the prototype following sensor board and processor board masses were.

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Table 17: Prototype mass

5.11 USB interface.

USB interface support has been provided to support high speed transfer of images to PC.

Acquisition through this interface is used and software can be developed to support

higher data rate for testing. Development of the hardware driver for the test at high speed

takes time and is beyond the scope of this thesis work.

5.12 Dimension

Sensor board = 30mm x 31mm

Processor board = 57.46mm x 57.46 mm

5.13 Modular printed circuit boards

Sensor PCB has been designed following figures shows the designed hardware for on

board camera. Design is modular and two PCBs are developed. Following figure shows

the PCB for sensor board.

Figure 39: Sensor PCB

Board Mass[grams] Sensor board with optics 11 Processor board 23

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Figure 40: Sensor PCB size compared to coin

Following figures shows the processor PCB and complete system designed for the

different applications.

Figure 41: Processor PCB

Complete System given with comparison for the developed camera.

Figure 42: Camera system, Euro coin and standard size card side by side

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Chapter 6

Software

6.1 Software for image acquisition

Embedded software in microcontroller performs various system initializations. It

initializes the processor clock, UART, I2C, Memory interfaces, IO ports functions and

DMA. It also configures sensor interrupts for frame transfer. Software state diagram

explain different microcontroller states chosen for testing purposes.

Figure 43: State flow diagram for microcontroller software

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Normally, after initialization microcontroller maintain it state in command acquisition by

enabling serial port interrupts, as soon as microcontroller get a valid command from the

host pc or testing application software, it respond with appropriated action. For e.g. when

microcontroller receives command for image acquisition, it acquires the image from the

FIFO and transfer it through serial port to PC and at the end of the transfer sends the valid

acknowledgment.

6.1.1 Software for sensor test application

Sensor test Application has been developed in Microsoft Visual C# 2008 Express

Edition. The software will provide the user an interface for what normally been acquired

from the image sensor. It also provides implementation for conversion algorithm.

Application has been developed to keep most of the things simple. The software sends

command through serial port and after the proper execution of the command, controller

send the acknowledgment only if the command is successful on the controller. If no

acknowledgment is received then after some time out software resumes its state.

6.1.1.1 Design considerations

Command and control and acquisition program developed to test the functionality of the

sensor and acquire Image. The user performs the different configuration of the software.

First of all select the appropriate parameter from the user interface to configure serial port

and then program the sensor through sensor initialization command via serial interface

port. These commands are received by microcontroller to program the registers specific

to the sensor. The core functionality includes the user interaction command to load the

data acquired to a text file through any terminal software for testing purpose. To acquire

image from the sensor user simply click the acquire image button after that the image will

be received by pc and displayed on the screen. The following diagram shows the main

layout of the application.

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Figure 44: Sensor testing program user Interface for Acquisition

Following use cases for the system was designed to fulfill different tasks. (Figure 45)

shows the case diagram developed for this system.

A. Perform Configuration

Users testing the sensor will have the flexibility to configure sensor parameter some

are specified as slider and selection values for the user. User must specify the correct

serial port for proper operation of the sensor.

A.1 Configure Image Sensor

A.1.1 Initialize defaults: Initialized the sensor with defaults for proper operation.

A.1.2 Adjust Gain (RGBA): Adjust the gain of the all channels and Individual

RGB channels

A.1.3 Flip Image (HV): for flip the image horizontally and vertically.

A.1.4 Bit & Bar Shift: Bar pattern Configuration for sensor to check the

alignment and color of sensor.

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A.1.5 General Register Update: Provide users the flexibility to manually input the

command and value for the required operation as stated in the data sheet.

A.2 Configure Serial Port: Use to configure serial port parameter for testing

operation 115200 baud rate must be selected by the user.

B. Load Sample File

This use case provide the user flexibility to load the sensor data saved as text file

where the sensor pixel data is save as decimal values using hyper terminal. It

provide the user additional flexibility for test purpose

C. Acquire Image

This actually sends the command to microcontroller to start sending data. The

command is use by user to trigger acquisition

D. Save Image

D.1 Save Image Bayer: This saves the image in Raw Bayer format without

RGB conversion

D.2 Save Image RGB: This will provide user to save the converted image

into RGB format and save it as bitmap file.

Figure 45: Use case diagram for sensor test application

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6.1.1.2 Panels to perform configuration

Following panels have been designed to support various use cases as discussed before.

Serial port configuration panel in is shown in the (Figure 46), (Figure 47) shows some of

the Control Configuration panel to configure sensor RGB gain values and also support

function to flip vertically and horizontally image in sensor hardware. (Figure 48) outlines

the advance control panel to configure sensor configuration manually it provide basic

support for sensor alignment using test pattern supported by sensor.

6.1.1.3 Software architecture

Each new control can be added by making new user control and extending it from

BaseConfiguration Class which just add a new panel in configuration tab. The class

diagram shows different classes and there relation used for the testing software.

Figure 46: Serial control

configuration panel

Figure 47: Gain control

configuration panel

Figure 48: Advanced sensor

control configuration panel

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Figure 49: Testing software class diagram

6.1.1.4 Acquire image implementation

User is responsible for selecting different command on the interface panel. The system

goes through various states depending on the command executed on the interface panel.

Following is the state diagram through which the system goes during various operation

executed by user.

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6.1.1.5 Bayer to RGB conversion algorithm

The sensor output used is in Bayer pattern for test purposes. Therefore, when the image is

receive on ground and need to be convert to color images a conversion algorithm has to

be employed to convert the image in to RGB. For the conversions we need to interpolate

the two other colors value at each pixel location. The propose algorithm has been taken

from the ref [BAYER] and conversion algorithm has been developed using the proposed

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correlated linear interpolation. Following flow diagram explains the conversion

algorithm.

Figure 50: Bayer to RGB conversion algorithm

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Chapter 7

System testing

During the development some images have been acquired, the sensor was configured for

8 bit RAW Bayer pattern. First two images with sensor were out of alignment therefore,

after certain modifications in the software image were perfectly synchronized. Normally,

sensor ICs in the market have some test mode to facilitated the development of software.

7.1 Images acquired for alignment problems

Figure 51: Misaligned color image with test pattern

Figure 52: Misaligned color image without test pattern

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However, first few image received above was unfortunately misaligned as shown in

(Figure 49). Following images are obtained after alignments is been done perfectly in

software.

Figure 53: Perfectly aligned color RGB image bar test pattern sky at the

background

Figure 54: Perfectly aligned color RGB image of the blue sky without test pattern

7.2 Testing of SCCB bus interface

After the successful image acquisition parameter SCCB interface of the sensor were

tested. The software gain slider send commands from the test application and program

gain configuration Registers. Gains were adjusted to full scale to so that the Bayer to

RGB conversion will be verified. Following RGB full gain images were obtained with

functionally testing for SCCB bus Interface.

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Figure 55: Color RGB image with full red gain settings

Figure 56: Color RGB image with full blue gain settings

Figure 57: Color RGB image with full green gain settings

Figure 58: Image with no AGC settings

7.3 Night image of the sky

Image of the sky has been taken at night since there is too much city light pollution

sensor image is quite noise and also image was acquired using automatic gain and

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exposure control setting. For correct images of stars sensor must be calibrated and

experiments must be done on clear sky night.

Figure 59: Across the sky and across the night

7.4 Near and far images

Distant and far images are being taken with same focus to study the image quality.

Figure 60: Image of far object

Figure 61: Image of object relatively close to camera

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7.5 Image of the Sun and sky at day time

Figure 62: Image acquired for clear sky with clouds

Figure 63: Image acquired for sun over Universität Würzburg Mensa building

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Chapter 8

Conclusion & future recommendations

Many satellites are currently planning mission to use camera in space on CubeSat.

CubeSats are the low cost platform for developing such system and maturing the

technology. These CubeSats provide the platform for developing the state of art

technology. Developing small things with lots of constraints on system always help in

developing these state of the art technologies.

For this thesis, work is carried out with regard to both Picosatellite and Nanosatellite.

Picosatellites especially for CubeSats requirements are very demanding for some of the

applications therefore, at present only the snapshot applications are possible. But a larger

platform Nano satellite has no such big constraints and can support and easily incorporate

small camera for the applications need as discussed. Small camera on Pico and Nano

satellite will be useful for many applications that have not been realized yet for any

mission. There is a growing demand to use this camera for such application.

Already developed camera from the market can be purchased and used but, designing a

system provides more flexibility in term of selection of components for particular design

objective and to support multiple applications. Also it provides flexibility for selecting or

designing particular optics for such mission. If a particular design is available, then PCB

can be modified to support the optical assembly. Previous satellite especially the

CubeSats launched with camera has been studied and system is proposed with different

alternative and related issues were discussed and prove to be feasible up to certain extent

P a g e | 89


dictated by optics design and availability. Off the self solution for optics are cheap and

recommended for normal application. But for demanding application custom optics

design is desirable.

Based on the application requirement different alternatives were proposed, since the

power and mass budget of current CubeSats missions are very demanding to meet, only

camera sensor module developed can be used for a single CubeSat at this point however,

the complete prototype with full functionality can be used on Nano satellite or triple

configuration CubeSats. For prototype only, optics compatible with camera with

reasonable field of view has been used. But this optics needs to be replaced with the

proposed state of the art solutions. Custom development of optic is a must demand to

achieve particular application or multiple application objectives.

Future work

Selected processer provides the middle level processing and acquisition capability and

can be used to develop system with efficient utilization of hardware recourses. Currently

designed system provides the platform for testing it on future mission. But in future

development, processor board design replaced by a DSP processor with DMA support is

recommended. DSP processor or FPGA based design can only meet the stringent

processing demand for many application e.g. to be used as an efficient star sensor and

Debris monitoring and TLP monitoring.

Power alternative for DSP based system are similar to the design system and would not

be a big issue for Nanosatellite system or triple configuration CubeSats. System needs to

be matured and for each task particular application software needs to be developed.

Certain mission planning and procedures needs to be developed for multiple task and

feasibility of such application with respect to orbit design need to be carried out for

particular mission. Moreover, optics design must be done to allow a flexible option for

optics modification to achieve particular mission objectives.

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Although preliminary level of testing is done for testing electronics and hardware

interfaces, but absolute calibration of system further required to be done on ground for

the matching scenario and received flux from the objects in space. Especially for different

scenario regarding application, flux values have to be worked out for different orbital

height and different object distance for absolute calibration of the equipment and optics

design and this requires lot of effort time and work. Also optical and absolute sensor

analysis is required to be investigated for such single or multiple applications. These

calculations require a lot of understanding with regard to optics design must be done as a

separate study.

P a g e | 91


References

[WIKI-SATCLASS] Miniaturized satellite. (2009, August 2). Retrieved August 2, 2009, from Wikipedia,The Free Encyclopedia: http://en.wikipedia.org /w/index.php?title=Miniaturized_satellite&oldid%20=305582543

[CanX4/5] CanX-4&5 (Canadian Advanced Nanospace eXperiment-4&5)

Retrieved August 3, 2009 from http://directory.eoportal.org /presentations/1001/10001040.html

[WIKI-FSTOP] F-number (2009, September 22). In Wikipedia, Free Encyclopedia.

Retrieved 13:45, August 22, 2009, from http://en. wikipedia.org/w/index.php?title=F- number&oldid=315505570.

[KODAK] Detector: Charged-COUPLED DEVICES Retrieve August 22,

2009 from http://www.kodak.com/US/en/digital/pdf/largePixels .pdf

[FARRELL06] Farrell, J., Xiao, F. and Kavusi, S., "Resolution and light

sensitivity tradeoff with pixel size," Proc. SPIE Vol. 6069, (2006). http://www. imageval.com/ public/Papers/ResolutionSensitivity Tradeoff_SPIE06

[TLP] AEOLUS, Transient Lunar Phenomena Studies. Retrieved August

22, 2009 from http://www.astro.columbia.edu/~arlin/TLP/ [STEYN] W.H. Steyn, M.J. Jacobs and P.J. Oosthuizen A High Performance

Star Sensor System for Full Attitude Determination on a Microsatellite Retrieve August 22, 2009 from http://staff.ee.sun.ac.za/whsteyn/Papers/AAS97_Star.pdf

[AERO] Space Debris Basics. Retrieved August 23, 2009 from

http://www.aero.org/capabilities/cords/ debris-basics.html

P a g e | 92


[NASA-OD] Orbital Debris Quarterly news Volume 13 issue 2. Retrieved August 23, 2009 from http://orbitaldebris.jsc.nasa.gov/newsletter/ pdfs/ODQNv13i2.pdf

[UN99] UNITED NATIONS New York, 1999. Technical Report on Space

Debris. Retrieved August 23, 2009 http://www.unoosa.org /pdf/reports/ac105/AC105_720E.pdf

[JASMINE] M. Suganuma, Y.Kobayashi, N. Gouda, T.Yano, Y.Yamada, N.

Takato, and M.Yamauchi. Development of a very small telescope for space astrometry surveyer http://sait.oat.ts.astro.it /MSAIt770406/PDF/2006MmSAI..77.1187S.pdf

[PRISM XI-IV] Akito Enokuchi, Masaki Nagai, Ryu Funase, Yuya Nakamura and

Shinichi Nakasuka. REMOTE SENSING BY UNIVERSITY OF TOKYO’S PICO-SATELLITE PROJECT “PRISM”. Retrieved on September 22 from http://www.dlr.de/iaa.symp/Portaldata/49 /Resources/dokumente/archiv5/0605_Enockuchi.pdf

[COMPASS-1] COMPASS-1 Phase-B Documentation http://www.raumfahrt.fh-

aachen.de/ downloads/Phase_B.pdf [AAU OBC] AAU CUBESAT OBC report Retrieved August 22, 2009 from

http://www.cubesat.auc.dk/dokumenter/OBC_design.pdf [AAU] AAU CubeSat Website. Retrieved August 27, 2009 from

http://www.cubesat .auc.dk/ [CAN-X1] Canada’s Smallest Satellite: The Canadian Advanced Nanospace

eXperiment (CanX-1) G. James Wells, Luke Stras, Tiger Jeans Space Flight Laboratory, University of Toronto Institute For Aerospace Studies. Retrieved August 28 from http://www.utias-sfl.net/docs/canx1-ssc-2002.pdf

[C628] The C628 Enhanced JPEG Module. Retrieved August 27, 2009

from http://www.electronics123.net/amazon/datasheet/C628.pdf [C328R] C328R User Manual. Retrieved August 27, 2009 from

http://ssdl.stanford.edu/ssdl/images/stories/AA236/0708A/Lab/Rover /Parts/cam_c328.pdf

P a g e | 93


[C3188A] C3188A 1/3” Color Camera Module With Digital Output Retrieved August 28, 2009 from http://www.quasarelectronics .com/kit-files/camera-module/d-c3188a.pdf

[OV7648FB] OV7648FB Color CMOS VGA (640 x 480) Camera Module

Preliminary datasheet Retrieved August 28, 2009 from http:// www.ime.co.kr/Data/Omni/Web-sources/OV7648FB_DS%20(1.0) .pdf

[CMUCAM3] CMUcam3 Datasheet September 22, 2007 Retrieve August 21,

2009 from http://www.superrobotica.com/download/cmucam3 /CMUcam3_datasheet.pdf

[EDMUND] Infinite Conjugate µ-Video™ Imaging Lenses CMOS Digital

Image Sensors. Retrieve August 22, 2009. http://www. edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=2196

[ALTOFT07] Ultra thin telephoto lens to revolutionise camera phones. Feb 2007.

Retrieved September 9, 2009 from http://www.mad4mobilephones .com/ultra-thin-telephoto-lens-to-revolutionise-camera-phones /410/

[TREMBLAY07] Eric J. Tremblay, Ronald A. Stack, Rick L. Morrison, and Joseph

E. Ford (Ultrathin cameras using annular folded optics) 2007 Published in Optical Society of America Retrieved September 25 from http://psilab.ucsd.edu/research/origami_optics /files/(journal_2007)_tremblay_(AO_Folded_imager1).pdf

[PRISM] PRISM project official website Retrieved September 22, 2009

from http://www.space.t.u-tokyo.ac.jp/prism/img/PRISM_Outlook .jpg

[BEYONDLOGIC] CMOS Digital Image Sensors. Retrieve August 22, 2009 from

http://www.beyondlogic.org/imaging/camera.htm [KODAK SENSOR] SOLID STATE IMAGE SENSORS TERMINOLOGY. Retrieved

August 30, 2009 from http://www.kodak.com/global/plugins /acrobat/en/business/ISS/supportdocs/terminology.pdf

[LITWILLER] CCD vs. CMOS, Facts and Fiction. Retrieved August 28, 2009

from http://www.dalsa.com/shared/content/Photonics_Spectra_ CCDvsCMOS_Litwiller.pdf

P a g e | 94


[OV7720] OV7720 VGA Product Brief. Retrieved August 28, 2009 from

http://www.ovt.com/uploads/parts/OV7720_PB%20(1.11)_web .pdf

[FURBER00] Furber, S. (2000). Arm System on Chip Archetecture. Addison

Wesley Longman Limited. [LPC2468] LPC2468 Product data sheet Rev.4. 17 Oct 2008. Retrieved August

29, 2009 from http://www.nxp.com/acrobat_download/datasheets/ LPC2468_4.pdf

[UMLPC2000] LPC24XX User manual Rev. 03 — 15 January 2009 [AVERLOGIC] Video Frame and Line FIFOs, Application Specialty Memory

Retrieved August 28, 2009 from http://www.averlogic .com/product_fifos.htm

[LPC-E2468] LPC-E2468 development board User Manual Rev.B, Febuarary,

2009 Retrieved August 28, 2009 from http://www.olimex.com/dev/pdf/ARM/LPC/LPC-E2468.pdf

[IAR] IAR KickStart Kit for LPC2468 Retrieved August 28 from

http://iar.com/website1/1.0.1.0/658/1/?item=prod_prod-/250 &group=prod_prod_grp-s1/34

[SCCB] Serial Camera Control Bus Specification 2002,Document Version

2. Appication note OmniVision [BAYER] RGB "Bayer" Color and MicroLenses Retrieved September 15,

2009. From http://www.siliconimaging.com/RGB%20Bayer.htm

Annex‐1 Processor selection table P a g e | 95


Maximum

Frequency[

MHz]

Manufacture

r

Processor Bus-Width Memory

Interfaces

Power

Consumpti

on

Direct

Camera

Interfac

e

DM

A

Output

Interfaces

Progra

m

Memor

y

Package Temperat

ure

Storage

Dimensio

n

40 Atmel AT91SAM7A1 32 bit Risk Direct

External Ram

TBD No Yes CAN

UART

SPI

No On

Chip

144-lead

LQFP

-40°C ~

85°C

20mmX

20 mm

40 Atmel AT91M40800 32-bit

RISC

Fully-

programmable

External Bus

Interface

TBD No Yes CAN

UART

SPI

I2C

No On

Chip

100-lead

TQFP

(-40°C to

85°C)

16mmX

16 mm

60 NXP LPC2292 16/32-bit

ARM

C 1.5 Watts

based on

Heat

Dissipation

No Yes CAN

UART

SPI

I2C

256 KB LQFP144

TFBGA144

(-40°C to

85°C)

22.15mm

X22.15

72 NXP LPC2378 16/32-bit

ARM

yes 1.5 Watts

maximum

Based on

Heat

Dissipation

No Yes Ethernet 100Mbps

USB

SSP

SPI

I2C

SD/MMC

512 KB

Flash

LQFP144 -40 ---85 22.15mmx

22.15mm

72 NXP LPC2468 16/32-bit

ARM

yes 1.5Watt

Maximum

No Yes Ethernet 100Mbps

USB

SSP

SPI

I2C

SD/MMC

512 KB

Flash

(LQFP208 -40 ---86 28mmX

28mm

700 TI TMS320DM643

7 Digital Media

Processor

VelociTI.2

™

Extensions

to VelociTI

Dynamic

Depends on

the

peripheral

turned on

Yes Yes I2C

McBsp

I2S and TDM

SPI

McASP

High End CAN

No On

Chip

S-PBGA-

N376

–40°C to

125°C

16X16

mm



Maximum

Frequency[

MHz]

Manufacture

r


Interfaces

Power

Consumpti

on

Direct

Camera

Interfac

e

DM

A

Output

Interfaces

Progra

m

Memor

y

Package Temperat

ure

Storage

Dimensio

n

Ethernet

PCI

200 TI tms320vc5509a Based on

ARM16/32

yes Dynamic

Depends on

the

peripheral

turned on

Yes yes USB Full-Speed

(12 Mbps)

McBSP port

64K

Rom

144-

Terminal

Low-Profile

Quad

Flatpack

-40 to 85 12,10mm

x

12,10mm

600 TI OMAP3515 ARM

Cortex-A8

16/32

yes 0,92871 Yes yes Video Port

(Configurable)

Graphics

Accelerator

MMC/SD

McBSP

Pin/Package

POP Interface

I2C

McSPI

HDQ/1-Wire

UART

USB

32 KB

(ARM

515-pin

PBGA

0 to 90,-

40 to 105

12,10mm

x

12,10mm

600 Analog

Devices

ADSP-BF561 32 bits yes ~ 2W

Dynamic

No yes Dual 12-channel

DMA controllers

SPI-compatible

port

UART with

support for IrDA

Dual watchdog

328K 297-ball

PBGA

–40°C to

+85°C

27mmX24

mm



Maximum

Frequency[

MHz]

Manufacture

r


Interfaces

Power

Consumpti

on

Direct

Camera

Interfac

e

DM

A

Output

Interfaces

Progra

m

Memor

y

Package Temperat

ure

Storage

Dimensio

n

timers

Dual 32-bit core

timers

2 parallel

input/output

peripheral

interface units

supporting

ITU-R 656 video

and glueless

interface to

analog front end

ADCs

Annex‐2 Processor board schematics P a g e | 98


Schematic Page 1 JTAG

1 23 45 67 89 1011 1213 1415 1617 1819 20

P2

MEC8-10-01-L-D-EM2

10K

R5

10K

R9

TDOTDITMSTRSTTCKRTCK

TRSTTDITMSTCKRTCKTDO

RST

RST

10K

R3

10K

R2

10K

R4

100K

R6

10K

R10

10K

R11

10K

R8

GND GND GND GNDGND

3.3V

10K

R73.3V

12

Y112MHZ

22pfC1

22pfC2

22pfC3

22pfC4

NA

R12

12

Y23278MHZ

GND

12

P1

AVCC

10K

R1

3.3V

GND

47K

R13 D11N4148

100nfC5

3.3V

GND

GND

ALARM37USB_D-2

52

DBGEN 9

TDO 2

TDI4

TMS6

TRST8

TCK 10

RTCK206

RSTOUT29

RESET35

XTAL1 44

XTAL246

RTCX134

RTCX2 36

NC30

NC117

NC141

LPC2468 - JTAG EXT OSCIC1F

LPC2468

S1

SW-PB

USB_D-2



Schematic Page 2 Power

GND

100uf 10V

C6

10uF

C810uf 6.3V

GNDGNDGND

3.3V

GND

560

R14

GND

100nFC10

100nFC11

100nFC12100nF

C13

100nFC14100nF

C15

100nFC16100nF

C17

100nFC18100nF

C19

GND

3.3V

GND

GND

100nFC20

100nFC21

100nFC22

0KR15 Chip 08053.3V

VSSIO33

VSSIO 63

VSSIO77

VSSIO93

VSSIO114

VSSIO133

VSSIO148

VSSIO169

VSSIO 189

VSSIO200

VSSCORE32

VSSCORE84

VSSCORE172

VSSA22

VDD(3V3)15

VDD(3V3)60

VDD(3V3)71

VDD(3V3)89

VDD(3V3)112

VDD(3V3)125

VDD(3V3)146

VDD(3V3)165

VDD(3V3)181

VDD(3V3)198

VDD(DCDC)(3V3)26

VDD(DCDC)(3V3)86

VDD(DCDC)(3V3)174

VDDA20

VREF24

VBAT38

LPC2468 - SupplyIC1G

LPC2468

GND

10uF

C230805 6.5 V

GND

100nFC24

470nHL1

3.3V

1 2TPC1

E

1 2TPC2

E

3.3V1 2

TPC3

E3.3V1 2

TPC4

E

VREFVBAT

VREF

VBAT

PROC VDD

D2

Vin Vout

GND

VR1

MICREL - MIC5209-3.3YS - IC REG LDO 500MA, 1%, 3.3V

.1uf

C7

GND

12

P3

Header 2

.1uf

C9

3.3V5V



Schematic Page 3 Memory and Sensor Interface

P2[

0]/P

WM

1[1]

/ T

XD

1/ T

RA

CE

CL

K15

4

P2[

1]/P

WM

1[2]

/ R

XD

1/ P

IPE

ST

AT

015

2

P2[

2]/P

WM

1[3]

/ C

TS

1/ P

IPE

ST

AT

115

0

P2[

3]/P

WM

1[4]

/ D

CD

1/ P

IPE

ST

AT

214

4

P2[

4]/P

WM

1[5]

/ D

SR

1/ T

RA

CE

SY

NC

142

P2[

5]/P

WM

1[6]

/ D

TR

1/ T

RA

CE

PK

T0

140

P2[

6]/P

CA

P1[

0]/

RI1

/TR

AC

EP

KT

113

8

P2[

7]/R

D2/

RT

S1/

TR

AC

EP

KT

213

6

P2[

8]/T

D2/

TX

D2/

TR

AC

EP

KT

313

4

P2[

9]/

U1C

ON

NE

CT

/ R

XD

2/ E

XT

IN0

132

P2[

10]/

EIN

T0

110

P2[

11]/

EIN

T1/

MC

IDA

T1/

I2S

TX

_CL

K10

8

P2[

12]/

EIN

T2/

MC

IDA

T2/

I2S

TX

_WS

106

P2[

13]/

EIN

T3/

MC

IDA

T3/

I2S

TX

_SD

A10

2

P2[

14]/

CS

2/ C

AP

2[0]

/SD

A1

91

P2[

15]/

CS

3/ C

AP

2[1]

/SC

L1

99

P2[

16]/

CA

S87

P2[

17]/

RA

S95

P2[

18]/

CL

KO

UT

059

P2[

19]/

CL

KO

UT

167

P2[

20]/

DY

CS

073

P2[

21]/

DY

CS

181

P2[

22]/

DY

CS

2/ C

AP

3[0]

/SC

K0

85

P2[

23]/

DY

CS

3/ C

AP

3[1]

/SS

EL

064

P2[

24]/

CK

EO

UT

053

P2[

25]/

CK

EO

UT

154

P2[

26]/

CK

EO

UT

2/ M

AT

3[0]

/MIS

O0

57

P2[

27]/

CK

EO

UT

3/ M

AT

3[1]

/MO

SI0

47

P2[

28]/

DQ

MO

UT

049

P2[

29]/

DQ

MO

UT

143

P2[

30]/

DQ

MO

UT

2/ M

AT

3[2]

/SD

A2

31

P2[

31]/

DQ

MO

UT

3/ M

AT

3[3]

/SC

L2

39

LP

C24

68 -

P2

IC1CLPC2468

P3[0]/D0 197

P3[1]/D1 201

P3[2]/D2 207

P3[3]/D3 3

P3[4]/D4 13

P3[5]/D5 17

P3[6]/D6 23

P3[7]/D7 27

P3[8]/D8191

P3[9]/D9 199

P3[10]/D10 205

P3[11]/D11 208

P3[12]/D12 1

P3[13]/D13 7

P3[14]/D14 21

P3[15]/D15 28

P3[16]/D16/ PWM0[1]/TXD1 137

P3[17]/D17/ PWM0[2]/RXD1 143

P3[18]/D18/ PWM0[3]/CTS1 151

P3[19]/D19/ PWM0[4]/DCD1 161

P3[20]/D20/ PWM0[5]/DSR1 167

P3[21]/D21/ PWM0[6]/DTR1175

P3[22]/D22/ PCAP0[0]/RI1 195

P3[23]/D23/ CAP0[0]/ PCAP1[0] 65

P3[24]/D24/ CAP0[1]/ PWM1[1] 58

P3[25]/D25/ MAT0[0]/ PWM1[2] 56

P3[26]/D26/ MAT0[1]/ PWM1[3] 55

P3[27]/D27/ CAP1[0]/ PWM1[4] 203

P3[28]/D28/ CAP1[1]/ PWM1[5] 5

P3[29]/D29/ MAT1[0]/ PWM1[6] 11

P3[30]/D30/MAT1[1]/RTS1 19

P3[31]/D31/MAT1[2] 25

LPC2468 - P3IC1D

LPC2468

P4[0]/A075

P4[1]/A179

P4[2]/A283

P4[3]/A397

P4[4]/A4103

P4[5]/A5107

P4[6]/A6113

P4[7]/A7121

P4[8]/A8127

P4[9]/A9131

P4[10]/A10135

P4[11]/A11145

P4[12]/A12149

P4[13]/A13155

P4[14]/A14159

P4[15]/A15173

P4[16]/A16101

P4[17]/A17104

P4[18]/A18105

P4[19]/A19111

P4[20]/A20/ SDA2/SCK1109

P4[21]/A21/ SCL2/SSEL1115

P4[22]/A22/ TXD2/MISO1123

P4[23]/A23/ RXD2/MOSI1129

P4[24]/OE183

P4[25]/WE179

P4[26]/BLS0119

P4[27]/BLS1139

P4[28]/BLS2/ MAT2[0]/TXD3170

P4[29]/BLS3/ MAT2[1]/RXD3176

P4[30]/CS0187

P4[31]/CS1193

LPC2468 - P4IC1E

LPC2468

D0D1D2D3D4D5D6D7D8D9D10D11D12D13D14D15

D0D1D2D3D4D5D6D7D8D9D10D11D12D13D14D15

A0A1A2A3A4A5A6A7A8A9A10A11A12

A13A14

A0A1A2A3A4A5A6A7A8A9A10A11A12A13A14

100nFC44

100nFC45

100nFC43

100nFC42

100nFC41

100nFC40

100nFC39

100nFC38

GND

3.3V

A0 23

A1 24

A2 25

A3 26

A4 29

A5 30

A6 31

A7 32

A8 33

A9 34

A10/AP 22

A11 35

A12 36

DQ02

DQ14

DQ25

DQ37

DQ48

DQ510

DQ611

DQ713

DQ842

DQ944

DQ1045

DQ1147

DQ1248

DQ1350

DQ1451

DQ1553

DQML 15

DQMH 39

CS 19WE 16CAS 17RAS 18

CLK 38CKE 37VDD11

VDD214

VDD327

VDDQ13

VDDQ29

VDDQ343

VDDQ449

VSS128

VSS241

VSS354

VSSQ16

VSSQ212

VSSQ346

VSSQ452

NC1 40

BA0 20

BA1 21

S2

SDRAM COMPONENT

nRASnCASWECSSD

CLK_SDENCLK_SD

DQMN0DQMN1

OEWE

nCA

SnR

AS

CL

K_S

D

CS

SD

EN

CL

K_S

D

DQ

MN

0D

QM

N1

NC

1N

C2

NC

3N

C4

NC

5

R/B2# 6R/B# 7

RE# 8

CE# 9CE2# 10

NC

11

VCC 12

VSS 13

NC

14N

C15

CLE 16

ALE 17

WE# 18

WP#19

DNU20 DNU21 DNU22

NC

23N

C24

NC

25N

C26

NC

27

NC

28

I/O029 I/O130 I/O231 I/O332

NC

33

NC

34

NC

35

VSS 36

VCC 37

PRE 38

NC

39

NC

40

I/O441 I/O542 I/O643 I/O744

NC

45

NC

46

NC

47

NC

48 U4

HY27UF081G2MD0D1D2D3D4D5D6D7

10K R343.3V

NA

ND

_RB

NAND_RB

ALECLE

0R36

NAR37CLEALE

100KR31

NAR30

3.3V

GNDCS1

CS1

GND

100nFC37

10uF/6.3VC36

3.3V

1 2TPC8

EGND

100KR35GND

OE_GATEWE_GATE

VCC14 GND 7

A1

B2 Y 3

U5A

DM74ALS32M

147

4

56

U5B

DM74HC32D3.3V

GND

CS1

OE_GATE

WE_GATE

OE

WE

4.7KR41

4.7KR403.3V3.3V

3.3V

GND

D[0

..15

]

A[0..14]

D4LED3

560

R38560R

3.3V

LED_STAT

LED_STAT

FR

AM

E

WE

_EN

AP

WD

NR

ES

ET

_SE

NS

OR

3.3V

SDASCL

CS_SEN

OE

WE_ENA

RESET_SENSOR

GND

PWDNFRAME

WRSTRRST

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 2627 2829 3031 3233 3435 3637 3839 40

P5

MHDR2X20GND

3.3V

SCL_FIFOSDA_FIFO

IRDY ORDY

nEIN

T1

D0D2D4D6

D1D3D5D7

OR

DY

1 2TPC9

E

RR

ST

IRDY

CS_SEN

OE_RCK

WR

ST

GND

100nFC35

GND

13

2 2TPC7

N_CE

N_CE

10KR32

NAR333.3V

GND3.3V

10KR39

3.3V



Schematic Page 4 UART USB and CAN & MMC Interface

P0[0]/RD1/TXD/ SDA194

P0[1]/TD1/RXD3/ SCL196

P0[2]/TXD0202

P0[3]/RXD0204

P0[4]/ I2SRX_CLK/ RD2/CAP2[0]168

P0[5]/ I2SRX_WS/ TD2/CAP2[1]166

P0[6]/ I2SRX_SDA/ SSEL1/MAT2[0]164

P0[7]/ I2STX_CLK/ SCK1/MAT2[1]162

P0[8]/ I2STX_WS/ MISO1/MAT2[2]160

P0[9]/ I2STX_SDA/ MOSI1/MAT2[3]158

P0[10]/TXD2/ SDA2/MAT3[0]98

P0[11]/RXD2/ SCL2/MAT3[1]100

P0[12]/ USB_PPWR2/ MISO1/AD0[6]41

P0[13]/ USB_UP_LED2/ MOSI1/AD0[7]45

P0[14]/ USB_HSTEN2/ USB_CONNECT 2/SSEL169

P0[15]/TXD1/ SCK0/SCK128

P0[16]/RXD1/ SSEL0/SSEL130

P0[17]/CTS1/ MISO0/MISO126

P0[18]/DCD1/ MOSI0/MOSI124

P0[19]/DSR1/ MCICLK/SDA1122

P0[20]/DTR1/ MCICMD/SCL1120

P0[21]/RI1/ MCIPWR/RD1118

P0[22]/RTS1/ MCIDAT0/TD1116

P0[23]/AD0[0]/ I2SRX_CLK/ CAP3[0]18

P0[24]/AD0[1]/ I2SRX_WS/ CAP3[1]16

P0[25]/AD0[2]/ I2SRX_SDA/ TXD314

P0[26]/AD0[3]/ AOUT/RXD312

P0[27]/SDA050

P0[28]/SCL048

P0[29]/USB_D+161

P0[30]/USB_D-162

P0[31]/USB_D+251

LPC2468 - P0IC1A

LPC2468

P1[0]/ ENET_TXD0 196

P1[1]/ ENET_TXD1 194

P1[2]/ ENET_TXD2/ MCICLK/ PWM0[1]185

P1[3]/ ENET_TXD3/ MCICMD/ PWM0[2] 177

P1[4]/ ENET_TX_EN 192

P1[5]/ ENET_TX_ER/ MCIPWR/ PWM0[3] 156

P1[6]/ ENET_TX_CLK/ MCIDAT0/ PWM0[4] 171

P1[7]/ ENET_COL/ MCIDAT1/ PWM0[5] 153

P1[8]/ ENET_CRS_DV/ ENET_CRS 190

P1[9]/ ENET_RXD0 188

P1[10]/ ENET_RXD1 186

P1[11]/ ENET_RXD2/ MCIDAT2/ PWM0[6]163

P1[12]/ ENET_RXD3/ MCIDAT3/ PCAP0[0] 157

P1[13]/ ENET_RX_DV 147

P1[14]/ ENET_RX_ER 184

P1[15]/ ENET_REF_CLK /ENET_RX_CLK182

P1[16]/ ENET_MDC 180

P1[17]/ ENET_MDIO 178

P1[18]/ USB_UP_LED1/ PWM1[1]/ CAP1[0] 66

P1[19]/ USB_TX_E1/ USB_PPWR1/ CAP1[1] 68

P1[20]/ USB_TX_DP1/ PWM1[2]/SCK0 70

P1[21]/ USB_TX_DM1/ PWM1[3]/SSEL0 72

P1[22]/ USB_RCV1/ USB_PWRD1/ MAT1[0] 74

P1[23]/ USB_RX_DP1/ PWM1[4]/MISO0 76

P1[24]/ USB_RX_DM1/ PWM1[5]/MOSI078

P1[25]/USB_LS1/USB_HSTEN1/MAT1[1] 80

P1[26]/USB_SSPND1/PWM1[6]/CAP0[0] 82

P1[27]/USB_INT1/USB_OVRCR1/CAP0[1] 88

P1[28]/USB_SCL1/PCAP1[0]/MAT0[0] 90

P1[29]/USB_SDA1/PCAP1[1]/MAT0[1] 92

P1[30]/USB_PWRD2/VBUS/AD0[4] 42

P1[31]/USB_OVRCR2/SCK1/AD0[5] 40

LPC2468 - P1IC1B

LPC2468

GND

GND

1KR2522R2622R27

GND15KR29

15KR28

GNDGND

3.3V

USB_PWRD2

USB_PWRD2

USB_D+2

USB_D-2USB_D+2

5V

ENA1

FLAG A2

FLAG B3

ENB4 OUT B 5GND 6IN 7OUT A 8

U3

LM3526

.1uf

C3210uFC31

GND

10KR22

10KR23

nUSB_PPWR2nUSB_OVRCR2

nUSB_OVRCR2

nUSB_PPWR2

Q1BC807

Q2

BC817

10KR16

2.2K

R18

22R20 15K

R19

330R17100uf 6.3V

C30

GND

GND

3.3V

3.3V

GND

MCIPWR

nEINT1

MCIDAT1MCIDAT0

MCICLK

MCICMDMCIDAT3

MCIDAT2

MCIDAT0MCIDAT1

MCIDAT2MCIDAT3

MCICLKMCICMD

MCIPWR

TXD1RXD1

TXD0RXD0

I2SRX_SDAI2STX_CLKI2STX_WSI2STX_SDA

RD1TD1

51R24

51R21

100nF

C33

100nF

C34

5V

TD1

RD1

CAN_H

CAN_L

3.3V

GND1

TXD2

VCC 3

RXD4 SPLIT 5

CANL 6

CANH 7STB8

U2

TJA1040

12

TPC5E

12

TPC6E

SD

A_F

IFO

SC

L_F

IFO

SDASCL

D3MBR0540

VBUS1

D-2

D+3

GND4

J1

440119-6

13

10

11

8

12

9

14

7

C1+1

C2+4

GND15

C1-3VCC 16

C2-5

V- 6

V+ 2

U1

MAX3232CPE

100nFC28

100nFC26

100nF

C29

100nFC27

100nFC25

GND

TXD1

RXD1TXD0

RXD0

GND

GND3.3V

12345

6789

10

P4

Header 5X2A

I2SRX_SDAI2STX_CLKI2STX_WSI2STX_SDA

GND

CD/DAT31CMD2 VSS13 VDD4 CLC5 VSS2

6 DAT07 DAT18

99

nCD10

SD CARDSD

SDCON

Annex‐3 Sensor board schematics P a g e | 102


Sensor Schematic Page 1

3.3V

D2

D3 D4D5 D6D7 D8

GND

3.3V

GND

SD

A

SCL

GND

DI01

DI12

DI23

DI34

VDD5

DI46

DI57

DI68

DI79

WE10

IE11

GND12

WCK13

WRST14

IRDY15

PLRTY16

TEST17

AVDD18

NC19

NC20

NC21

AGND22

SDAEN23SCL24SDA25GND26

OE 34RE 35

DO6 37DO5 38DO4 39

DO242

DO044

RESET 27NC 28

RCK 32

RRST 31

ORDY 30

VDD 29

GND 33

DO7 36

VDD 40DO3 41

DO143

AL440bP1

FIFO

3.3V

3.3V

FD0FD1FD2FD3

FD4FD5FD6FD7

FD0 FD1FD2 FD3FD4 FD5FD6 FD7

SDASCL

SDA_FIFOSCL_FIFO

GND

GNDGND

GND

3.3V

3.3V

10uF

C7Cap Pol3

10K

R6

10uF

C6

GND

RESET_SEN

D2D3D4D5

D6D7D8

D9D9

WE_SEN

100nFC1 100nFC2

GND

CS_SEN

CS_SEN

OE_RCK

PC

LK

RS

_FIF

O

PCLK

SE

NC

LK

3.3V

GND

VCC14GND 7

A1

B2Y 3

U2A

WE_SEN

WE_ENA

HREF

HREF

WE_ENA

RESET_SEN

VSYNC

GND

AV

DD

1V

RE

FH

2V

RE

FN

3R

ST

B4

PWDN5

GND6

AVDD7

D98

D79

D510

D511

D1

12

XC

LK

13

VC

CIN

T14

PC

LK

15

DG

ND

16

DO

VD

D17

D2

18

D4 19D6 20D8 21D0 22

HREF 23VSYNC 24

SCL 25

SD

A26

FS

IN27

AG

ND

28

OV7720 Sensor

U1CMOS Sensor

PWDN

FRAME

PWDN

1 2

TPC2

E1 2

TPC1

ESCL_FIFOSDA_FIFO

3.3V

3.3V

D[2..9]

10R1

10R2

10R3

10R4

10R5

100nFC3100nFC4

100nFC5

GND GND GND

VCC14 GND

7B5

Y 6A4

U2BVSYNC

FRAME

3.3V

3.3V

GND

GND2

OUT3

TRI1

VCC4

Y1

24MHz Oscillator

3.3V 3.3V

GND

SENCLK

.1uFC8

WRST

WRST

RRST

RRST

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 2627 2829 3031 3233 3435 3637 3839 40

P2

MHDR2X20GND

3.3V

3.3VGND

12

TPC5E

IRDY ORDY

SCL_FIFOSDA_FIFO

IRDY ORDY

GND12

TPC3E

1 2TPC4

EOE_RCK

GND

Annex‐4 Sensor Board Schematics P a g e | 103


Documents

2010:013 MASTER'S THESIS