SHARAD: MARS 2005 Shallow Sounder SHARAD: SHALLOW SOUNDER Science & Technical Meeting Rome, 19 - 20 - 21 March 2002

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder

SHARAD:SHARAD:SHALLOW SOUNDERSHALLOW SOUNDER

Science & Technical MeetingScience & Technical Meeting

Rome, 19 - 20 - 21 March Rome, 19 - 20 - 21 March 20022002

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Table of Contents (1/2)Table of Contents (1/2)

• Design Status: Overview

• Summary of SHARAD Requirements

• Summary of SHARAD System Parameters

• SHARAD Architecture

• SHARAD Operative Modes

• SHARAD Budgets

• Design Status: Analysis and Trade-offs

• Design Status: Description

• DES - Digital Section

• TX and RX - Radiofrequency sections

• ANT - Antenna

• Thermo-Mechanical & S/C Collocation, Budgets


• Design & Development Approach

• Model Philosophy

• Integration and Testing Flow

• Ground Testing Approach

• Calibration and Validation

• Management & Schedule

• Team Composition

• Schedule

• Receivables

• Deliverables

• Product Assurance (Mission Assurance)

Table of Contents (2/2)Table of Contents (2/2)


Design Status:Design Status:Overview - System Overview - System architecturearchitecture

R. CROCI E. ZAMPOLINI FAUSTINI

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Summary of Radar requirementsOverview - Summary of Radar requirements

• Vertical Resolution: 10 - 20 metres

• Penetration Depth: 300 - 1000 metres

• Horizontal resolution: 300 - 1000 metres (along track)

• Observation Geometry: Nadir looking

• Desired centre frequency: @ 20 MHz

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Preliminary System ParametersOverview - Preliminary System Parameters

• Antenna Efficiency: > 10%

• Centre Frequency: 20 MHz

• Radiated Peak Power: 10 W

• Pulse Length: 300 s (single chirp)

• Pulse Bandwidth: 10 MHz

• Pulse Repetition Frequency: 200 Hz

• Vertical Swath Range: 60 s (9 Km - free space, 3km – e=9)

• Topographic Margin: 40 s (6 Km - free space)

• Receive window: 400 s (300+60+40)

• A/D Resolution: 8 bits

• A/D frequency: 26.6 MHz

• Maximum Data Rate: 17 Mbit/s

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder OverviewOverview - Design status - Design status

• System Analysis: “Analysis and Trade-off” Document Released

• Antenna: Under final trade-off

• Transmitter: Preliminary Requirements Specification Document (“Mini Spec”) released.

• Receiver: Preliminary Requirements Specification Document (“Mini Spec”) released

• DES: Preliminary Requirements Specification Document (“Mini Spec”) released

• Open Points:

• On-board Processing

• Tracking on board: Open vs Close loop

• Data Rate/Volume

• ADC number of bits

• PRF

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - SHARAD Block DiagramOverview - SHARAD Block Diagram

• SHARAD interfaces with S/C by means of:

• Power I/F (from Bus to SHARAD, used also as on/off switch)

• Command I/F (from OBDH to SHARAD)

• Telemetry I/F (from SHARAD to OBDH, option not baselined)

• TC/TM I/F (between OBDH and SHARAD, option under evaluation)

• Science Data I/F (from SHARAD to SSR, used also as HK Telemetry)

ANT

TX

RX

DES

OBDH

SSR

SHARAD

Spacecraft

Power

RDS

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Architecture block diagramOverview - Architecture block diagram

Imped.Match.

T/RSwitchPADrv

DCG

EchoProc.

EchoForm.

Timing&

Freq.

Supervisor

Power

MO

SDI

TX

RX

DES

LNAFilterADC

controlof allotherunits

DES

TX

Ant

RX

Power

CMD

TM/TC

SDGC

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Architecture baselineOverview - Architecture baseline

• The SHARAD sounder is composed by the following main building blocks.

• The DES, in charge of all the digital functions, i.e• Instrument command & control• Signal generation by means of a Digital Chirp generator• Handling and formatting of the digitised received signal

• The Transmitter & front-End.

• Amplify Tx signal

• Provide matching vs the antenna load

• Provide duplexing function

• The Rx (packed together with DES in the RDS)

• Amplifies, filter, digitises the echo signal

• The Antenna

• radiates the Tx signal and pick-up the echo

• can allocate part of the matching network (TBC)

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Architecture considerations (1)Overview - Architecture considerations (1)

GENERAL

• Considering the involved frequencies, it has been chosen to avoid frequency conversions in both Tx (generation of chirp directly on a 20 MHz carrier) and in Rx.

• The Rx foresees direct sampling at the RF frequency. Sampling is performed at fs < fmax/2, with controlled aliasing (fs > 2 times filter bandwidth)

• This approach allows to avoid down conversion and/or sin/cos demodulation, while keeping the sampling rate low.

• The current baseline for ADC resolution is 8 bit, with possibility to select a smaller number of bits for transmission to ground.


-1

-1

Interpolator

Delay

26.6 MHz

13.3 MHz

13.3 MHz

6.65 MHz

6.65 MHz

6.65 MHz

6.65 MHz26.6 MHz

Overview - Architecture considerations (2)Overview - Architecture considerations (2)

RECEIVER - UNIFORM SAMPLING ON THE CARRIER

• If the received echo is directly sampled on the carrier at a frequency fS such as fS=4 f0 /(2M-1) (M integer), achieved samples will be alternatively I and Q samples multiplied by +/- 1.

• Samples re-alignment may be accomplished in the digital section using DSP or FPGA: the latter to be preferred in the high speed digitisation for its possibility to implement parallel architectures (subject to trade-off ).

• Uniform Sampling on the Carrier may be applied to a 10 MHz Chirp (on 20 MHz Carrier) at a rate of 26.6 MHz.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Architecture considerations (3)Overview - Architecture considerations (3)

DE-RAMPING TRADE-OFF

• Use of de-ramping receiver has been considered to reduce the sampling rate and the overall data volume

• PROsPost de-ramping bandwidth is proportional to the width of the tracking window -> significant reduction for small windows (< 100 sec)

• CONsEffects of amplitude/phase distortions cannot be compensated after de-ramping: therefore, increase of side lobes introduced by hardware non-idealities cannot be compensated by ground processing.

• For this reason, the baseline foresees no de-ramping.


ON-BOARD PROCESSING/TRACKING TRADE-OFF

• Current baseline does not foresee on-board processing, with possible exception on data coherent pre-summing to limit the data rate.

• Availability of raw data on ground would allow to optimise the compensation function (to recover HW errors) and processing parameters without risk of data loss: the drawback is a larger data volume for a give operating time.

• Similarly, in order to simplify design and limit the risk areas, it has been assumed an open-loop control for the tracking window positioning, based on platform-supplied orbit data (no tracking of the surface).

• Even if surface tracking has to be implemented, requiring a limited on-board processing (i.e., range compression), recommended approach is to use compressed data for the tracker only, and send the raw data to ground.

Overview - Architecture considerations (4)Overview - Architecture considerations (4)


Design Status:Design Status:Overview - OperationsOverview - Operations

E. ZAMPOLINI FAUSTINI

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Operations: Support ModesOverview - Operations: Support Modes

• CHECK/INIT

• HW and SW initialisation of the Digital Electronics Section DES with RX and TX Off.

• STANDBY

• RX and TX Off; Digital Electronics Section generates Housekeeping Telemetries and accept Macrocommands.

• WARM-UP1

• The Receiver, in addition to DES, is switched On.

• WARM-UP2

• The Transmitter , in addition to DES and RX, is switched On.

• SAFE/IDLE

• Used after recovery actions due to severe hardware or software anomalies possibly encountered in any of the available modes (either belonging to Support or Operation classes).

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Operations: Operational ModesOverview - Operations: Operational Modes

• Measurement Modes

• SHARAD performs scientific measurements. A variable data rate will be produced depending on the specific processing setup. Sub-Modes are defined to accommodate different types of processing and data rates: SS LOW, SS HIGH, RAW DATA.

• CALIBRATION

• SHARAD acquires unprocessed sounding data.

• RECEIVE ONLY

• SHARAD performs passive measurements (mainly during the cruise phase).

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - OperationsOverview - Operations

• SHARAD operating modes transition diagram

OperationalModes

Me

asu

rem

en

tM

od

es

SilentModes

SupportModes

OFFHeating

Check/Init

StandBy Safe/Idle

WarmUp1

WarmUp2

RawData

SSLow

SSHigh

Calib

RcvOnly

Autonomoustransitions

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Operations: How SHARAD Overview - Operations: How SHARAD operatesoperates

GENERALITIES

• Heaters Control will be performed by the S/C

• Heaters typically OFF during the Operative Part of the Orbit

• SHARAD will be turned ON and OFF every Orbit (TBC)

• SHARAD will go through its SUPPORT and OPERATION Modes autonomously.

• This way to operate will be accomplished by means of automatic mode transitions (SUPPORT Modes have a fixed duration) or following the instructions listed in the OPERATIONS SEQUENCE TABLE


Mode

Sel

Mode Duration

in PRI

DCG

Config.

Param 1

4 19 4

Param 2Spares

Mode

Sel

Mode Duration

in PRI

DCG

Config.

Param 1 Param 2Spares

1

N

Overview - Operations: How SHARAD Overview - Operations: How SHARAD operatesoperates

OPERATIONAL SEQUENCE TABLE

• Two different type of Operational Sequence Table (OST) are envisaged:

• Default Operation Sequence Table (DOST) stored in EEPROM

• Orbit Dedicated Operation Sequence Table (ODOST) loaded in RAM by dedicated MCMD

• OST Composition (Data Field of dedicated Serial MCMD):

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Operations: How SHARAD Overview - Operations: How SHARAD operatesoperates

SHARAD COMMANDABILITY

• The instrument can be commanded using packet MCMD

• SHARAD can receive TC Packets only in STANDBY Mode

• SHARAD can be switched ON/OFF by the spacecraft in any operative mode without any special reactivation procedure other than the nominal switch-on procedure.

SHARAD OBSERVABILITY

• 4 Analog Temperature Sensor Channels

• Packet TM covering both HK (current mode, time, voltages, MCMD Accepted/Refused, etc.) and Events (Mode Transitions and Anomalies)

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Operations: What SHARAD Overview - Operations: What SHARAD needs needs

ON-BOARD

• Heater Lines Controlled by S/C

• Command to load Orbiter Time (mandatory for each flyby)

• Command to load the PARAMETERS TABLE (mandatory for each flyby)

• Command to load the OPERATIONS SEQUENCE TABLE (optional but typically used for each flyby)

ON-GROUND (every orbit)

• Accurate Orbit Prediction/Reconstruction (time to p, H, Vt, Vr)

• Predicted/Reconstructed Attitude

• Knowledge of solar zenith angle


Design Status:Design Status:Overview - BudgetsOverview - Budgets

R. CROCI

L. MARINO E. ZAMPOLINI FAUSTINI

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Mass BudgetOverview - Mass Budget

Unit masses (Kg)

Note: these estimations are still preliminary (waiting for feedback from unit suppliers) Note: these estimations are still preliminary (waiting for feedback from unit suppliers) and do not include instrument contingency - up to 15 kg .and do not include instrument contingency - up to 15 kg .

More reliable figures can be provided following feedback from unit suppliers.More reliable figures can be provided following feedback from unit suppliers.

Specified/Predicted

Allocated Margin

DES 2.5 3.0 0.5Rx 1.0 1.5 0.5RDS SUBTOTAL 3.5 4.5 1.0TFE 2.0 2.5 0.5ANTENNA 1.8 2.0 0.2ELECTRONICSSUBTOTAL

7.3 9.0 1.7

HARNESS 0.7 0.75 0.05THERMAL CONTROL 1.8 2.0 0.2

TOTAL 9.8 11.75 1.95

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Power BudgetOverview - Power Budget

Power Consumption (W)

+ Replacement heater Power: currently allocated 10 W+ Replacement heater Power: currently allocated 10 W

(not simultaneous to operating power)(not simultaneous to operating power)

Allocated DES 30.0 Rx 9.0 RDS SUBTOTAL 39.0 TFE 13.0 TOTAL

51.0

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Data VolumeOverview - Data Volume

Data Volume

Sampling Window us 400ADC Number of bit 8Orbits per day 4Acquisition Time min 30PRF Hz 200 150Bandwidth Chirp MHz 7 10 7 10Number of Pulses MHz 1 1 1 1Sampling frequency MHz 16 26.6 16 26.6Data Rate Mbps 10.2 17 7.65 12.75Data Volume Gbit 73.7 122.6 55.3 92Data Volume: 7 echoes presummed Gbit 10.5 17.5 7.9 13.1


Design Status:Design Status:Analysis and Trade-offsAnalysis and Trade-offs

L. MARINO

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Analysis and Trade-Off - ContentsAnalysis and Trade-Off - Contents

• Observing Geometry

• Principles of Operation

• Investigation Approach

• Preliminary Parameters Sizing

• Surface Clutter and Penetration Depth

• Surface Received Power Levels

• Surface Signal to Noise Ratio

• Subsurface Received Power Levels

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Analysis - Observation Geometry & SAR Analysis - Observation Geometry & SAR ConceptConcept

Zmax

H

Echoes dynamic rangeafter signal compression & SAR Processing

Surface Clutter

Echo from subsurface

PR range presentation time

PD range presentation time

time

time

time

Along Track

Cross Track

v

Height

Isorange Contour

Isodoppler Contour

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Key Design ElementsKey Design Elements

• System Key design elements:

• Center frequency: 20 MHz

• One frequency modulated radar pulse: • length 300 s; • bandwidth 10 MHz.

• Radiated Peak Power: 10 W

• System Key design elements Subjected to Trade-Off:

• Pulse Repetition Frequency: 200 Hz

• Open Loop control for the tracking window positioning

• A/D Resolution: 8 or a selectable lower number of bits

• A/D frequency (on the Carrier Frequency): Max 30 Mhz

• On ground, echoes are processed through SAR based techniques to enhance the azimuth resolution and therefore clutter reduction.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Investigation ApproachInvestigation Approach (1/3)(1/3)

• The ability of SHARAD to achieve its science objectives will be largely dependent on the electrical properties of the soil.

• A few representative category of the Martian surface composition has been selected as most meaningful:

Category ’ Tan

I-1 5 0.004Andesite

I-2 8 0.004Sediments II-1 1.5 0.03

II-2 5 0.03II-3 9 0.03

DifferentTerrestrial

Basalts III 7.1 0.014

• The scenarios employed for the modelling of the detection subsurface are:

I/W) Ice/water interface detection scenario: the pores are filled with ice from the surface down to a depth below which liquid fills the pores. D/I) Dry/ice interface detection scenario: the pore-filling material is considered to be gas up to a depth below which ice fills the pores.


• To assess the interface detection performance the back scattering cross sections of concurrent echoes coming from the surface and subsurface layers have to be evaluated.

• Fractal geometric description of the surface in the classical Kirchhoff approximation:

H=1 Geometric Optic model (Simpson and Tyler, 1982):

H=0.5, Hagfors’ model (Hagfors, 1964):

H

s

ss

sin

sH

Rs

HH

H

H

H

s

ss

HHH

H

H

1

)(cos2)(

2

!)1(

)(cos2)(

2

cos

)0()(

2

1/11

1

02

22

/1/1/1

1

2

2

0

2

2

242

2

10 cos2

0 s

tg

H es

R

5.1

42

24

42

2

5.00 4cos

8

0

s

sin

s

RH


• Fresnel reflectivity for a subsurface layer located at a depth z:

Martian Crust s dB R12 dB dB/ Km MHz

Material’s I/ W D/ I I/ W D/ I I/ W D/ I

Category 50% 20% 50% 20% 50% 20% 50% 20% 50% 20% 50% 20%

I-1 -9.5 -9 -12 -9.5 -10 -17.5 -21 -29.5 0.95 1.3 1 1.3I-2 -8 -7 -9.5 -7.5 -9.5 -17 -23 -32 1.2 1.7 1.3 1.7II-1 -14 -17 -25.5 -22 -13.5 -21 -17 -25 4.4 5.8 3.8 5.5II-2 -9.5 -9 -12.5 -9.5 -10 -17.5 -21 -29 7 10 7.5 10II-3 -7.5 -6.5 -9 -7 -9.5 -17 -24 -33 9.5 13.5 10.5 14III -8.5 -7.5 -10 -8 -9.5 -17 -22.5 -31.5 3.9 5.5 4.3 5.5

z

d

zzSS RR 0

1.022

012

,12, 101

mdBfdB /tan108.1 07

Being:

R212 : Fresnel reflection coefficient of such interface;

R201 : Fresnel reflection coefficient of the surface.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Preliminary Parameters Sizing Preliminary Parameters Sizing (1/3)(1/3)

• For a chirp radar (as required in planetary missions due to the low power available), range resolution is a function of the transmitted bandwidth:

z=c/(2 B )

• In terrestrial dry rocks, values of usually range between 4 and 10, decreasing for increasing porosity.

Shallow Range Resolution

0,0

5,0

10,0

15,0

20,0

25,0

30,0

1 2 3 4 5 6 7 8 9

Ran

ge

Res

olu

tio

n [

m]

Bandwidth 5 MHz

Bandwidth 7 MHz

Bandwidth 10 MHzII-1 I-1 II-2 III I-2 II-3

• Requirement: 10 meters.

• Except for the II-1 category, just a 7 MHz Chirp bandwidth met the requirement.


• Along-Track Resolution: the 300 - 1000 m requested, imply the use of synthetic aperture processing techniques for resolution enhancing.

RAZ= H / 2LS

• Cross-Track Resolution: limited by the radar vertical resolution.

Pulse-limited resolution :

R=2 x (c H/B) ~ 5.3 6.9 Km for 10 MHz bandwidth;

~ 6.3 8.3 Km for 7 MHz Bandwidth.

• In presence of specular surfaces, the horizontal resolutions will be limited by the Fresnel zone size:

r= (H /2) ~ 1.5 Km

1.6 s < Tint < 2.9 s for RAZ=300 m

0.5 s < Tint < 0.8 s for RAZ=1000 m

H ~400 kmVsc~3360 m/s

H ~ 230 kmVsc~3440 m/s


• Aliasing in the observed doppler spectrum must be avoided.

• PRF has to be sized over the off nadir observation angle beyond which the surface clutter returns are 30 dB lower the nadir surface echo:

304

coslog150

:5.042

24

100

0

s

sinH dB

30coslog10

0:1

2

2

2410

0

0

s

tg

dB eH

sinV

PRF o22

• The doppler bandwidth to be sampled by the system will be enveloped by twice the angle:

PRF 200 Hz Martian Surface Coverage 35%

PRF 150 Hz Martian Surface Coverage 28%

PRF Selection based on: 0(0)/0()=30 dB

70,0

120,0

170,0

220,0

270,0

320,0

370,0

0,04 0,045 0,05 0,055 0,06 0,065 0,07 0,075 0,08 0,085 0,09 0,095 0,1

s()

PR

Fm

in (

Hz)

Hagfors Model

Geometric Optic Model

Surface Coverage 28%

Surface Coverage 35%


• Surface return echoes are considered as clutter, because the subsurface discontinuity detection may be reduced from the surface back-scattering.

• Synthetic aperture processing improves the subsurface detection capability thanks to the reduction of the off-nadir surface clutter power: typical improvement: ~ 10 dB.

AnalysisAnalysis - - Surface Clutter and Penetration Depth Surface Clutter and Penetration Depth (1/3)(1/3)

H

Z

R

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Surface Clutter and Penetration Depth Surface Clutter and Penetration Depth (2/3)(2/3)

• Improvement Factor coming from Processing Doppler at a depth z:

Improvement Factor: Chirp Bandwidth 10 MHz

5,0

7,0

9,0

11,0

13,0

15,0

17,0

19,0

50 250 450 650 850 1050

Depth (m)

IF (

dB

)

dielectric constant 1.5dielectric constant 5dielectric constant 9

Improvement Factor: Chirp Bandwidth 7 MHz

5,0

7,0

9,0

11,0

13,0

15,0

17,0

19,0

50 250 450 650 850 1050

Depth (m)

IF (

dB

)

dielectric constant 1.5dielectric constant 5dielectric constant 9

1

1

)1(22

2

nnnHHnR

HRIF

ZZAZ

ZAZ

Z

H

ZHDPL 22

ZZ nHHnwidthStrip )1(22

z

Satellite Motion Direction

Raz

Sector of PL Circular Crown

Sector of Pulse LimitedCircle

Satellite Motion Direction

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Surface Clutter and Penetration Depth Surface Clutter and Penetration Depth (3/3)(3/3)

RKm 300s() 0,06

Signal/Clutter (Andesite BCA)

-5,0

0,0

5,0

10,0

15,0

20,0

50 100 150 200 250 300

Depth (m)

Sig

na

l to

Clu

tte

r (d

B)

Hagfors: I-1 I/W 50%

G.O.: I-1 I/W 50%

Hagfors: I-1 I/W 50% after Processing Doppler

G.O.: I-1 I/W 50% after Processing Doppler

Signal/Clutter (Andesite WCA)

-35,0

-30,0

-25,0

-20,0

-15,0

-10,0

50 100 150 200 250 300

Depth (m)

Sig

na

l to

Clu

tte

r (d

B)

Hagfors: I-2 D/I 20%

G.O.: I-2 D/I 20%

Hagfors: I-2 D/I 20% after Processing Doppler

G.O.: I-2 D/I 20% after Processing Doppler

Signal/Clutter (Basalts BCA)

-15,0

-10,0

-5,0

0,0

5,0

10,0

15,0

50 100 150 200 250 300

Depth (m)

Sig

na

l to

Clu

tte

r (d

B)

Hagfors: II-1 D/I 50%

G.O.: II-2 D/I 50%

Hagfors: II-1 D/I 50% after Processing Doppler"

G.O.: II-2 D/I 50% after Processing Doppler

Signal/Clutter (Basalts WCA)

-45,0

-40,0

-35,0

-30,0

-25,0

-20,0

50 100 150 200 250 300

Depth (m)

Sig

na

l to

Clu

tte

r (d

B)

Hagfors: II-2 D/I 20%

G.O.: II-3 D/I 20%

Hagfors: II-2 D/I 20% after Processing Doppler

G.O.: II-3 D/I 20% after Processing Doppler

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Surface Received Power Levels Surface Received Power Levels (1/2)(1/2)

• Rough surfaces cannot have returns higher than specular ones: maximum back-scattered power is provided by Fresnel Model.

• Minimum Power Level:

- Geometric model;

- wavelength scale r.m.s. slope 0.06;

- Martian Crust Category II-1 (sediments);

- Scenario D/I (porosity 50%);

- Satellite altitude 400 Km.

• Maximum Power Level:

- Fresnel model;

- Martian Crust Category II-3 (basalts);

- Scenario: interface I/W (porosity 20%);

- satellite altitude 230 Km.

43

022

)4( R

AGPP pR

Hagfors G. O. Fresnel

PpG2

dBW 10 10 10 10m 15 23,5 23,5 23,5(I-1 I/W 50% s()=0.06) 94,9 86,4 105,0

643 -33 -33 -33

R4 Km 300 -219,1 -219,1 -219,1

Pr dB -123,6 -132,1 -113,5

Pr min GO s()=0,06 R=400 Km -122 dBm

Pr max Specular R=230 Km -78 dBm

Pr dynamic range 44 dB

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Surface Received Power Levels Surface Received Power Levels (2/2)(2/2)

PTG2 10 dBw

Bandwidth 10 MHz

P.L. Resolution 6000 mrange resolution) 15 m

V0 3,4 Km/ s

f0 20 MHz

Height 300 Km

s() 0,06

Martian Crust Hagfors: Power ReceiveddBm G.O. Power ReceiveddBm Fresnel Power ReceiveddBm


Category 50% 20% 50% 20% 50% 20% 50% 20% 50% 20% 50% 20%

I-1 -93,6 -93,1 -96,1 -93,6 -102,1 -101,6 -104,6 -102,1 -83,5 -83,0 -86,0 -83,5I-2 -92,1 -91,1 -93,6 -91,6 -100,6 -99,6 -102,1 -100,1 -82,0 -81,0 -83,5 -81,5II-1 -98,1 -101,1 -109,6 -106,1 -106,6 -109,6 -118,1 -114,6 -88,0 -91,0 -99,5 -96,0II-2 -93,6 -93,1 -96,6 -93,6 -102,1 -101,6 -105,1 -102,1 -83,5 -83,0 -86,5 -83,5II-3 -91,6 -90,6 -93,1 -91,1 -100,1 -99,1 -101,6 -99,6 -81,5 -80,5 -83,0 -81,0III -92,6 -91,6 -94,1 -92,1 -101,1 -100,1 -102,6 -100,6 -82,5 -81,5 -84,0 -82,0

• Surface Power Levels for all the Scenarios and Categories of the presented Martian Crust materials and for the worst case of wavelength-scale r.m.s. slope of 0.06.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Galactic and Extra-Galactic NoiseGalactic and Extra-Galactic Noise

• The graphic shows Galactic background measurements at 5.2, 9 , 15.6, 23 MHz using half wave dipoles together with those made by Novaco and Brown (1978). The smooth curve is derived from a simple model of the Galaxy:

eIe

II egg

1

Ig() and Ieg(): brightness contributed by the Galaxy and by the extra-galactic sources;(): optical depth for the absorption.

2,5E-20

1,1E-20

0,0093

6,2E-21

50183

-79,0KTbB (dBm)

Noise Power: PG

Ieg

I

SGP Galactic Noise: Cane Model

Tb (K)

Ig

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Surface Signal to Noise Ratio Surface Signal to Noise Ratio (1/2)(1/2)

• For the Fresnel Model the Doppler Processing Gain is negligible.

• Synthetic Aperture will be limited by the Fresnel Circle number of integrable pulses 4.

Hagfors G.O. Fresnel

P G2 dBW 10 10 10 10

m 15 23,5 23,5 23,5(I-1 I/W 50% s()=0.06) 20,4 11,9 36,5 62,6 62,6 68,5

643 -33 -33 -33

R Km 300 -219,1 -219,1 -219,1

K (=1.38 10-23) 228 228 228

TG 10 MHz Bandwidth -49,0 -49,0 -49,0

us 300 -35,2 -35,2 -35,2

N (GAZ) 25 14,0 14,0 0,0

Single Look SNR dB 22,2 13,7 30,2

DDS

AZ BRv

RB

v

LRRNA 222

00

05.23

032

033

032

43

022

)4(

2.2

)4()4( vKTR

BGP

v

BR

KTR

GPN

KTFLR

AGP

N

S

G

DpD

G

pp

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder AnalysisAnalysis - - Surface Signal to Noise Ratio Surface Signal to Noise Ratio (2/2)(2/2)

• SNR for all the Scenarios and Categories of the presented Martian Crust materials and for the worst case of wavelength-scale r.m.s. slope of 0.06.

PTG2 dBW 10

BW MHz 10PRF Hz 200Duty cycle () 0,06Ti s 2,2Ls m 7487Res P.L. m 6000Raz m 301range res.) m 15,0V0 Km/sec 3,40BD Hz 11,4f0 MHz 20s() 0,06

Martian Crust HagforsModel SNR dB Geometric Optic Model SNR dB Fresnel Model SNR dB


Category 50% 20% 50% 20% 50% 20% 50% 20% 50% 20% 50% 20%

I-1 22,2 22,7 19,7 22,2 13,7 14,2 11,2 13,7 30,2 30,7 27,7 30,2I-2 23,7 24,7 22,2 24,2 15,2 16,2 13,7 15,7 31,7 32,7 30,2 32,2II-1 17,7 14,7 6,2 9,7 9,2 6,2 -2,3 1,2 25,7 22,7 14,2 17,7II-2 22,2 22,7 19,2 22,2 13,7 14,2 10,7 13,7 30,2 30,7 27,2 30,2II-3 24,2 25,2 22,7 24,7 15,7 16,7 14,2 16,2 32,2 33,2 30,7 32,7III 23,2 24,2 21,7 23,7 14,7 15,7 13,2 15,2 31,2 32,2 29,7 31,7


• Subsurface Dynamic represents the attenuation which the signal is subjected to when crosses the Martian subsurface and is reflected at depth z.

z

RRPP way

SRRSS

2

2201

212 1

zRR

Dynamic wayS

SS

2

2201

212 1

Martian Crust Depth [m] limited by dynamic 30 dBMaterial’s I/ W D/ I

Category 50% 20% 50% 20%

I-1 1527 907 1103 441I-2 1200 627 701 191II-1 386 228 514 241II-2 254 111 157 55II-3 175 82 81 21III 379 197 236 77

Martian Crust Subsurface Dynamic [dB]: depth m 300Material’s I/ W D/ I

Category 50% 20% 50% 20%

I-1 5,6 15,0 14,1 26,6I-2 7,7 18,7 20,1 34,0II-1 23,2 38,4 14,0 36,5II-2 35,6 68,0 50,1 79,1II-3 51,5 89,0 74,0 108,2III 23,8 41,5 35,2 54,7

AnalysisAnalysis - - Subsurface Received Power Levels Subsurface Received Power Levels (1/2)(1/2)

• Subsurface and Crust Materials have been assumed with the same characteristics: category, scenario, r.m.s. rugosity slope.

Pr SS min GO s()=0,06 R=400 Km -212 dBmPr SS Max Specular R=230 Km -87 dBm

Pr SS range 125 dB


Martian Crust Hagfors: Subsurface Power dBm G.O. : Subsurface Power dBm Fresnel: Subsurface Power dBm

Material’s I/ W D/ I I/ W D/ I I/ W D/ I (m)

Category 50% 20% 50% 20% 50% 20% 50% 20% 20% 50% 20% 50% 20%I-1 -99,2 -108,1 -110,2 -120,2 -107,7 -116,6 -118,7 -128,7 -89,1 -98,0 -100,1 -110,1 6,7I-2 -99,8 -109,8 -113,7 -125,6 -108,3 -118,3 -122,2 -134,1 -89,7 -99,8 -103,7 -115,5 5,3II-1 -121,3 -139,5 -123,7 -142,6 -129,8 -148,0 -132,1 -151,1 -111,2 -129,4 -113,6 -132,5 12,2II-2 -129,2 -161,1 -146,7 -172,7 -137,7 -169,6 -155,2 -181,2 -119,1 -151,0 -136,6 -162,6 6,7II-3 -143,1 -179,6 -167,1 -199,4 -151,6 -188,1 -175,6 -207,8 -133,0 -169,5 -157,0 -189,3 5,0III -116,4 -133,1 -129,4 -146,8 -124,9 -141,5 -137,8 -155,2 -106,4 -123,0 -119,3 -136,7 5,6

• Subsurface Power Levels for all the Scenarios and Categories of the presented Martian materials and for the worst case of wavelength-scale r.m.s. slope of 0.06.

• Power Levels have been computed at 300 meters of penetration depth.

AnalysisAnalysis - - Subsurface Received Power Levels Subsurface Received Power Levels (2/2)(2/2)

PTG2 10 dBw

Bandwidth 10 MHz

P.L. Resolution 6000 mrange resolution) 15 m

V0 3,4 Km/ s

f0 20 MHz

Height 300 Km

s() 0,06

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder • If it exists the relationship (with M

integer):

• samples of the signal s(t) are:

• Samples re-alignment may be accomplished by DSP or FPGA (the latter to be preferred for its parallel architectures - subject to trade-off ).

• Signal Spectrum of a 7 MHz Chirp on 20 MHz Carrier, after Uniform Sampling on the Carrier at a rate of 16 MHz:

4

120

M

f

f

s

212)12(

2cos22

nMsinTnsTnQ

nMnTsnTI

cc

cc

-20 2820124-4 MHz-12

Analysis - Sampling TechniqueAnalysis - Sampling Technique

-1

-1

Interpolator

Delay

16 MHz

8 MHz

8 MHz

4 MHz

4 MHz

4 MHz

4 MHz16 MHz

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Analysis - Data VolumeAnalysis - Data Volume

Echo Rx Interval

Pulse Lenght

300 us

PenetrationDepth

60 us

Penetration Depth of3 Km

dielectric constant 9

Topo-graphicMargin

40 us

Topographic Margin of6 Km

• The SHARAD Radar Sounder is able to work 30 minutes per orbit and four orbits per day.

• Avoiding De-ramping (availability of raw data on ground) allows to optimise processing parameters without risk of data loss.

• Coherent pre-summing may be foreseen in order to limit data rate.

• In order to simplify design and limit the risk areas, it has been assumed an Open-Loop control for the Sampling Window positioning, based on platform-supplied orbit data.

Sampling window 400 secNumber of ADC bit 8Orbits per Day 4Acquisition Time 30 min

Uniform Sampling on the Carrier

PRF Hz 200 150Bandwidth Chirp MHz 7 10 7 10Number of Pulses MHz 1 1 1 1Sampling frequency MHz 16 26.6 16 26.6Data Rate Mbps 10.2 17 7.65 12.75Data Volume Gbit 73.7 122.6 55.3 92Data Volume: 7 echoes presummed Gbit 10.5 17.5 7.9 13.1


Design Status:Design Status:DescriptionDescription

F. BERNARDINIR. CROCIM. MAPPINIM. MARCOZZIP. NOSCHESE

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder IntroductionIntroduction

• The SHARAD system is composed of four units:

• DES: Digital Electronics Section

• TX: Transmitter section

• RX: Receiver section

• ANT: Antenna

DES and RX are mechanically joined to form a single section:

• RDS: Receiver and Digital Section

ANT

TX

RX

DES

OBDH

SSR

SHARAD

Spacecraft

Power

RDS


DIGITAL ELECTRONICS SECTION

F. Bernardini, M. Mappini

ANT

TX

RX

DES

OBDH

SSR

SHARAD

Spacecraft

Power

RDS

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - IntroductionDES - Introduction

• The Digital Electronics Section is the heart of SHARAD and concentrates many functions including:

• command and control of the experiment,

• low-power radar pulses generation,

• science data processing and formatting,

• timing.

• The DES is also the main interface between SHARAD and the S/C and provides:

• a Command Interface,

• a Science Data Interface,

• a Power Interface.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - Functional requirementsDES - Functional requirements

• The Digital Electronics Section will provide:

• command and control capability (by S/C OBDH)no telemetry is envisaged toward S/C a part from thermistors measurement points and heaters control.

• command and control capability of system unitson the basis of ground-generated macrocommands sent as standard CCSDS Telecommand Source Packets.

• science data interface toward S/C SSRscience data are formatted as standard CCSDS Telemetry Source Packets(it might include system telemetry information).

• digital chirp generator (DCG)this component has the purpose of digitally generating the radar pulse waveform and providing it to the transmitter section; two option are under evaluation: NCO (Numerical Controlled Oscillator) based DCG and MRO (Memory Readout Oscillator) based DCG.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - Functional requirementsDES - Functional requirements

• The Digital Electronics Section will provide (continued):

• master oscillator (MO)this high-stability oscillator is the frequency source for all system clocks which need to be synchronised to radar operations.

• timekeeping and synchronisation of other unitsradar operations are strictly synchronised by means of dedicated circuitry.

• echo formatter/processorthe amount of processing required for echoes samples is to be defined; possible application include: digital filtering (FIR) and decimation, I & Q samples generation, echoes pre-summing and programmable bit selection.

• power distribution to the other units DES distributes S/C power to other SHARAD units.

• additional computationsDES shall also provide for real-time updating of orbit-related parameters and other values which may be required.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - Proposed architectureDES - Proposed architecture

• The design of the Digital Electronics Section follows this guideline::

Timing&

Freq.

Filter

DC/DC

Supervisor

PROM EEPROM

RAM

DCG

EchoProcessor 8

CMDI/F

SDI/F

EchoFormatter

MO

6

+5Vdig

+12V an.

-12V an.

+5VDES

+28V TX

TX_PWR_ON_OFF

TX_CHIRP

TX_GATE

TX_SYNCH

TX_TXRX

RX_GATE

RX_CLOCK

RX_ATTSEL

RX_DVALID

RX_DATA

+28V Unreg

DES_PPS

DES_CMD

DES_SD

DES_TC_Sp1

DES_TC_Sp2

DES_TM_Sp1

DES_TM_Sp2

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - S/C InterfaceDES - S/C Interface

• The DES concentrates the majority of SHARAD - S/C interfaces.

Not shown are thermistor and heater interfaces between S/C and TX section (1 heater and 1 thermistor, redounded).

DES_PWR_Main

DES_PPS

DES_CMD_Main

DES_CMD_Red

DES_CMD_Select

3

3

DES_SD_Main3DES_SD_Red

3

RDS_HTR_Main

RX_TH_Main

RDS_HTR_Red

RX_TH_Red

DES_PWR_Red

DES_TC_Spare_1

DES_TC_Spare_2

DES_TM_Spare_1

DES_TM_Spare_2

SHARADSpacecraft

RX

DES

RDS

DES_TH_Main

DES_TH_Red

• Basic assumptions foresee that no serial digital telemetry is provided from SHARAD to S/C.

• Usage of optional discrete TC/TM lines (2+2) between S/C and DES is under review.

• DES will receive a 1 Hz time-tick signal (DES_PPS), which will be used for SHARAD OBT synchronisation purposes when not in operating mode.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - Power InterfaceDES - Power Interface

• The S/C will provide:

• main power to SHARAD, 28 V (+8/-6 V), as a redundant (1+1), commandable (ON/OFF), power line;

• survival heater (2 + 2) power to SHARAD, 28 V (+8/-6 V), as a redundant, commandable (ON/OFF) power line to each of the RDS and TX.

• DES will provide:

• +28V power to the TX section,

• +5V, +/-12V power (TBC) to the RX section.

Unit'sheaters

S/C

Main

Red.SHARAD Main Power

Red.

Main

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - C&C InterfaceDES - C&C Interface

• The S/C will route ground-generated commands to SHARAD by means of a redundant LVDS-based serial digital interface.

• Data are exchanged as IP packet, NRZ-L formatted, at a rate of 515 Kbps.

Instrument

C&DHA

B

Cmd Clock

Cmd Valid

Cmd

RT

RT

RT

RT

RT

RT

5V_A RS

EN

EN

S/C

R

Vcc

Cmd Clock

Cmd Valid

Cmd

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - Science Data InterfaceDES - Science Data Interface

• SHARAD will send Science Data to the S/C Solid State Recorder.

• Science Data Source Packet (IP encapsulated) are NRZ-L formatted, and sent at a variable data rate (up to 30 Mbps).

• SHARAD will send data to the SSR continuously (within an operating sequence).

SSR Instrument

A

B

Data Clock

Data Valid

Data

RT

RT

RT

RT

RT

RT

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - ProtocolsDES - Protocols

• Data exchanges between S/C OBDH and SHARAD (commands) and between SHARAD and S/C SSR are based upon IP/UDP encapsulation.

• SHARAD will use CCSDS Source Packet formats for all its data exchanges.

UDP

IP

LVDSLow Speed

MCMD

UDP

IP

LVDSHigh Speed

SD/TLM

MROCIP

SHARAD

Science DataInterface

CommandInterface

InstrumentDependant

Formats

InstrumentDependantFormats

MCMD Data

UDP Datagram

IP Datagram

MROCIP Frame

SD/TLM DataSource Packet

Source Packet

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - Internal InterfacesDES - Internal Interfaces

• The DES provides two sets of interfaces: one toward the TX section and one toward the RX section.

• Most of the interfaces are digital bi-level (RS-422) discrete signals.

• The usage of some telemetry signals from the other units (like TX_LEVEL and RX Spares) is still under review.

TX

TX_CHIRP

TX_TXRX

TX_SYNCH

TX_PWR_ON_OFF

TX_PWR

TX_GATE

TX_LEVEL

DES

TX_Spare_1

TX_Spare_2

RXRX_ATTSEL

RX_CLOCK

RX_GATE

RX_PWR_DIG

RX_DATA 8

RX_Spare_2

RX_Spare_1

RX_DVALID

DES

RX_PWR_AN_P

RX_PWR_AN_N

6

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder DES - Mechanical layoutDES - Mechanical layout

• The assembly (or assemblies) composing SHARAD should be assembled from Eurocard sized PCBs assembled inside common mechanical trays (MARSIS heritage), which in turn will be stacked to form a single mechanical unit.

• These modules have variable height.


RADIO FREQUENCY SECTION

R. Croci

ANT

TX

RX

DES

OBDH

SSR

SHARAD

Spacecraft

Power

RDS


DIG. CTRL ATTEN. DATA

DATA VALID

ADC SYNC

ADC_CK

Rx_GATEATT_CTRL

ADC

Receiver Module (1)Receiver Module (1)

• The receiver module is in charge of:

• Amplify and filter the received signal

• Implement the gain control function

• Convert the Rx signal to digital form, with sampling rate such to unambiguously cover the intentional bandwidth

• No de-ramping, nor down conversion are performed within the receiver: signal is sampled directly at RF (20 MHz +/- 5 MHz)

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Receiver Module (2)Receiver Module (2)

• Main Rx (preliminary) requirements are the following:

• Equivalent A/D full scale input @ max gain: -85 dBm

• Gain control range: 31 dB

• No of bits: 8 (TBC)

• Noise figure: <= 1.0 dB

• Bandwidth: 10 MHz

• Sampling rate will be in the order of 12 MHz, allowing unambiguous acquisition of the signal spectrum.

• Out-of-band noise will be rejected before sampling by a lumped-element band pass filter


Pc=- 79 dBmPc=- 79 dBm

Ng=-82 dBmNg=-82 dBm

Ps<-87 dBmPs<-87 dBm-85 dBm-85 dBm

-127 dBm-127 dBm

-54 dBm-54 dBm

-96 dBm-96 dBm Max gainMax gain

RangeRange

Min gainMin gain

RangeRange

Receiver Module (3)Receiver Module (3)

• Nominal gain setting will be such to bring the clutter signal few dB below A/D full scale.

• Gain control range of 31 dB will provide adequate flexibility to cope with different scenarios and to compensate for ageing, tolerances, etc


• Tentative mass/power requirements are the following:

• mass: <= 1.0 kg

• envelope: 1 standard module, 20 mm height

• Power consumption: <= 6 W

• The Rx module will be housed in a standard module (~180x130) which will be integrated in the RDS unit.

• Regulated secondary volgages will be provided by the DC/DC converter located inside the DES.


• Preliminary requirements for the Rx module unit have been released in order to allow start of technical discussion with potential suppliers.


Antenna MatchingNetwork

Power Ampl

Rx/TxSwitch

To Rx

Driver

DC/DCconverter

Control Circuit

Chirp

Transmitter / Front End Module (1)Transmitter / Front End Module (1)

• The Transmitter / Front-End unit is in charge of the following main tasks:

• Power amplification

• T/R duplexing

• Impedance matching wrt the antenna

• The TFE is powered directly from the unregulated main bus (routed via RDS) by its own DC/DC converter.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Transmitter / Front End Module (2)Transmitter / Front End Module (2)

• TFE main requirements:

• Effective power delivered to the antenna: >= 10W

• Duty cycle max = 7.5% (300 sec @ 250 Hz)

• Bandwidth: 10 MHz

• Mass: <= 2.0 Kg

• Envelope: <= 360 x 80 x 120 mm

• Power consumption: <= 11 W

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Transmitter / Front End Module (3)Transmitter / Front End Module (3)

• Preliminary requirements for the TFE unit have been released in order to allow start of technical discussion with potential suppliers.

• Critical points have been identified in:

• Amplifier efficiency

• Matching network

• In particular, achieving good matching over the required 10 MHz bandwidth with a single matching network is regarded as a challenging task

• Special care shall also be placed in controlling the conducted emissions toward the power bus: this requires a large capacitor bank for energy storage within the unit.


ANTENNA SECTION

P.Noschese

ANT

TX

RX

DES

OBDH

SSR

SHARAD

Spacecraft

Power

RDS


ANTENNA DESIGN OBJECTIVEANTENNA DESIGN OBJECTIVE

•DESIGN AN EFFICIENT , LIGHT AND SIMPLE WIDE DESIGN AN EFFICIENT , LIGHT AND SIMPLE WIDE BAND HF ANTENNA BAND HF ANTENNA

•MIMIMIZE AS MUCH AS POSSIBLE ANY MIMIMIZE AS MUCH AS POSSIBLE ANY INTERFERENCE EITHER OPTICAL AND INTERFERENCE EITHER OPTICAL AND ELECTROMAGNETIC WITH THE EXISTING S/C ELECTROMAGNETIC WITH THE EXISTING S/C EQUIPMENTSEQUIPMENTS

•DEVELOPE AN ELECTROMAGNETIC S/C MODEL IN DEVELOPE AN ELECTROMAGNETIC S/C MODEL IN ORDER TO EVALUATE ACCURATELY HOW THE ORDER TO EVALUATE ACCURATELY HOW THE SCATTERING FROM THE S/C BODY AND SOLAR SCATTERING FROM THE S/C BODY AND SOLAR ARRAY CHANGE THE SHARAD HF ANTENNA ARRAY CHANGE THE SHARAD HF ANTENNA ELECTRICAL PERFORMANCESELECTRICAL PERFORMANCES


ANTENNA REQUIREMENTSANTENNA REQUIREMENTS

• REQUIRED BANDWIDTH : 15-25 MHzREQUIRED BANDWIDTH : 15-25 MHzGOAL : 10-25 MHzGOAL : 10-25 MHz

• MIN. GAIN VARIATION IN THE FOV ± 10° (3 MIN. GAIN VARIATION IN THE FOV ± 10° (3 dB)dB)

• MIN. INPUT IMPEDANCE SPREAD VS. MIN. INPUT IMPEDANCE SPREAD VS. BANDWIDTHBANDWIDTH

SOLAR SOLAR ARRAY POSITIONARRAY POSITION

• ANTENNA EFFICIENCY BETTER THAN 10%ANTENNA EFFICIENCY BETTER THAN 10%


ASSUMPTIONSASSUMPTIONS

•ANTENNA ELECTRICAL PERFORMANCES HAVE BEEN ANTENNA ELECTRICAL PERFORMANCES HAVE BEEN ANALYZED VS. 2 ANALYZED VS. 2 SOLAR ARRAY POSITIONS SOLAR ARRAY POSITIONS CONSIDERED AS WORSTS CASESCONSIDERED AS WORSTS CASES

__ SOLAR ARRAYS FULL OPENED HORIZONTALLYSOLAR ARRAYS FULL OPENED HORIZONTALLYAND SLIGHTLY DIVERGENT TOWARD THE NADIRAND SLIGHTLY DIVERGENT TOWARD THE NADIR_ SOLAR ARRAYS FULL OPENED AND ROTATED _ SOLAR ARRAYS FULL OPENED AND ROTATED

OF OF 135° INTO THE NADIR PLANE135° INTO THE NADIR PLANE

• RADAR “OUT OF SERVICE” WHEN THE S/C SOLAR RADAR “OUT OF SERVICE” WHEN THE S/C SOLAR ARRAYS ARE BOTH BEAMING TO THE NADIR ARRAYS ARE BOTH BEAMING TO THE NADIR


ASSUMPTIONSASSUMPTIONS

• S/C DRAWINGS AS FROM E-MAILS S/C DRAWINGS AS FROM E-MAILS

• HGA ANTENNA PARALLEL TO THE HGA DECK ONLY HGA ANTENNA PARALLEL TO THE HGA DECK ONLY WHEN WHEN THE S/C IS STOWED AS SHOWN INTO THE THE S/C IS STOWED AS SHOWN INTO THE DOCUMENT DOCUMENT SHARAD_LMA_Q_AND_A.DOCSHARAD_LMA_Q_AND_A.DOC DATED DATED 03/19/02 03/19/02

• CLEARENCE BETHWEEN HGA AND HGA DECK 10-20 CLEARENCE BETHWEEN HGA AND HGA DECK 10-20 CM. CM. AS FROM E-MAIL AND TELECON AS FROM E-MAIL AND TELECON


ANTENNA OPTIONSANTENNA OPTIONS

• DIPOLE 7.0 MT. LONG ON A 3 MT. BOOMDIPOLE 7.0 MT. LONG ON A 3 MT. BOOM

• MONOPOLE .25 LAMBDA LONG @ 20 MHzMONOPOLE .25 LAMBDA LONG @ 20 MHz

• LOOP AT THE NADIR DECK LOOP AT THE NADIR DECK LMA dimensions (1.6 Mt. x LMA dimensions (1.6 Mt. x

2.24 Mt.)2.24 Mt.)

• IMPROVED LOOP IMPROVED LOOP (HGA deck side 1.6 by 1.8 (HGA deck side 1.6 by 1.8

Mt. HIRISIS deck side Mt. HIRISIS deck side .95 by 1.6 Mt .95 by 1.6 Mt @20 cm away from HGA deck panel)@20 cm away from HGA deck panel)


Antenna summaryAntenna summary

SHARAD HF ANTENNA SUMMARY

G-maxvs.

frequency 10° FOV

G-maxvs.

Solar Arrayposition

MIN.In-Band

efficiency

ZisensitivityVs. Solar

Array position

Mech.Complex.

Match.Networksrequired

DIPOLE 1.5 dB 1 dB < 10% LOW HIGH > 1MONOPOLE 4.0 dB 1 dB > 30% LOW HIGH >1Loop @ Nadir Deck 2.5 dB 2 dB << 10 % HIGH LOW N.A.Loop Improved (ALS) 1.5 dB <1 dB > 25 % LOW LOW 1


DIPOLE ANTENNA and S/C modelingDIPOLE ANTENNA and S/C modeling

CASE ACASE A CASE BCASE B


Dipole, Gain variation vs. Elevation angleDipole, Gain variation vs. Elevation angle


Higher freq.Higher freq. Center freq.Center freq. Lower freq.Lower freq.


Dipole, VSWR variation vs. FrequencyDipole, VSWR variation vs. Frequency

1 5 1 7 1 9 2 1 2 3 2 51 6 1 8 2 0 2 2 2 4

Fre q u e n cy (M H z)

0

10

20

30

40

50

VS

WR

1 5 1 7 1 9 2 1 2 3 2 51 6 1 8 2 0 2 2 2 4


0

10

20

30

40

50

VS

WR



MONOPOLE ANTENNA and S/C modelingMONOPOLE ANTENNA and S/C modeling


SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder MONOPOLE, Gain variation vs. Elevation MONOPOLE, Gain variation vs. Elevation

angleangleHigher freq.Higher freq. Center freq.Center freq. Lower freq.Lower freq.



MONOPOLE, VSWR variation vs. FrequencyMONOPOLE, VSWR variation vs. Frequency

1 5 1 7 1 9 2 1 2 3 2 51 6 1 8 2 0 2 2 2 4


0

2

4

6

8

10

VS

WR

1 5 1 7 1 9 2 1 2 3 2 51 6 1 8 2 0 2 2 2 4


0

2

4

6

8

10

VS

WR


SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder LOOP ANTENNA (LMA siting) and S/C LOOP ANTENNA (LMA siting) and S/C

modelingmodeling



LOOP ANTENNA (LMA siting)LOOP ANTENNA (LMA siting) Gain variation vs. Elevation angle Gain variation vs. Elevation angle




LOOP ANTENNA (LMA siting)LOOP ANTENNA (LMA siting) VSWR vs. Frequency VSWR vs. Frequency

1 5 1 7 1 9 2 1 2 3 2 51 6 1 8 2 0 2 2 2 4


0

1000

2000

3000

4000

VS

WR

1 5 1 7 1 9 2 1 2 3 2 51 6 1 8 2 0 2 2 2 4


0

1000

2000

3000

4000

VS

WR



IMPROVED LOOP (ALS) and S/C modelingIMPROVED LOOP (ALS) and S/C modeling



IMPROVED LOOP (ALS) IMPROVED LOOP (ALS) Gain variation vs. Elevation angleGain variation vs. Elevation angle



SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder IMPROVED LOOP (ALS)IMPROVED LOOP (ALS) VSWR vs. Frequency VSWR vs. Frequency

1 5 1 7 1 9 2 1 2 3 2 51 6 1 8 2 0 2 2 2 4


0

10

20

30

40

5

15

25

35

VS

WR

1 0 2 0 3 0 4 01 5 2 5 3 5


0

10

20

30

40

5

15

25

35

VS

WR


CONCLUTIONSCONCLUTIONS

•BASED ON ASSUMPTIONS RELATIVE TO S/C DIMENTIONS AND BASED ON ASSUMPTIONS RELATIVE TO S/C DIMENTIONS AND CLEARANCES TAKEN, TWO ANTENNA TOPOLOGY HAVE BEEEN CLEARANCES TAKEN, TWO ANTENNA TOPOLOGY HAVE BEEEN ANALYZED WITH THE MOM TECHNIQUE, LINEAR AND LOOP ANALYZED WITH THE MOM TECHNIQUE, LINEAR AND LOOP ANTENNAS. ANTENNAS.

•WE POINT OUT THAT, A LOOP ANTENNA CAUSE OF ITS LOW Q WE POINT OUT THAT, A LOOP ANTENNA CAUSE OF ITS LOW Q ENSURES THE BEST ELECTRICAL PERFORMANCES IN TERMS OF ENSURES THE BEST ELECTRICAL PERFORMANCES IN TERMS OF BANDWIDTH. BANDWIDTH.

•ALS CONCEIVED A NON CANONICAL LOOP ANTENNA THAT, ALS CONCEIVED A NON CANONICAL LOOP ANTENNA THAT, USING BASICALLY THE S/C AS A GROUND RETURN, FULL MEETS USING BASICALLY THE S/C AS A GROUND RETURN, FULL MEETS THE STRINGENT REQUIREMENTS, OUTPERFORMING ALL THE THE STRINGENT REQUIREMENTS, OUTPERFORMING ALL THE OTHER ANTENNAS ANALYZED WITH ALSO A BANDWIDTH OTHER ANTENNAS ANALYZED WITH ALSO A BANDWIDTH PERFORMACE CREDIT. PERFORMACE CREDIT.


THERMO-MECHANICAL REQUIREMENTS,

S/C COLLOCATION and BUDGETS

M. Marcozzi

ANT

TX

RX

DES

OBDH

SSR

SHARAD

Spacecraft

Power

RDS


TX

MLI

Radiator Panel

MRO Nadir Panel

+X (into page)

+Y

+Z

RDS

Preliminary Mechanical design & issuesPreliminary Mechanical design & issues

• At the present time there are 2 configurations:

• A single unit instrument

• 2 separate box ( RDS+TX).

• At the moment there are not specific configuration indication from the spacecraft on the shape instrument (I, L or T), beside the total dimensions of the boxes.

• The single unit configuration permits maximum reutilization of existing design of the MARSIS units. Also facilitate the I/F with S/C.


+X

+Z

+Y

RDSTX

S/C configuration and P/L collocationS/C configuration and P/L collocation

• The disposition of the SHARAD instrument on the nadir deck should be agreed with the orbiter in function also of the SHARAD units configuration.

• Radiator Position and orientation: The radiator panel should be oriented in the positive crosstrack direction (+Y), where the normal to the face should look at space and with no direct solar irradiation except for TBC slewing maneuvers.


•Radiator PanelRadiator Panel

MARCI Optics MARCI Optics

AntennaAntenna +X

+Y

+Z (out)

CRISM OSU CRISM OSU

•TransmitterTransmitter

ReceiverReceiver

DowntrackDowntrack

SHARAD possible collocation & orientation SHARAD possible collocation & orientation (T)(T)


•Transmitter + Antenna BoxTransmitter + Antenna Box•ReceiverReceiver

•Radiator PanelRadiator Panel

MARCI Optics MARCI Optics

AntennaAntenna +X

+Y

+Z (out)

CRISM OSU CRISM OSU

SHARAD Possible collocation & orientation SHARAD Possible collocation & orientation (I)(I)

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Orbit, attitude and operational mode Orbit, attitude and operational mode considerationsconsiderations

• The baseline assumption for the SHARAD operative modes is that:

• SHARAD will operates during the eclipses of the orbits.

• One operation for orbit, for a max operating time of 26 min (at peak power) is envisioned (ref. MARSIS).

• Orbital assumptions for the science phase:

• 200x400 km orbit

• 92.8° inclination, 15:00h LTAN

• Period: 114 min, Eclipse time: 30 min

• Thermal Rad. Environment

• Solar: 710-490 W/m^2

• Albedo-IR: Nadir panel is worst case


Min. Temperature [°C] Max. Temperature [°C]

Operating -20 +55

Acceptance -25 +60

Qualification -30 +65

Non Operating -40 +70

Start – up -35

Table: Unit Temperature ranges.

Mechanical & Thermal issuesMechanical & Thermal issues• Mechanical issues:

ICD documentation is required ASAP.

• I/F Connections:

• Number of connection per box: 6 (TBC)• Size: M4 or M5 (TBD)• Repartition of mass responsibilities for the I/F

• Temperature limits:

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder Overview - Mass BudgetOverview - Mass Budget

Unit masses (Kg)

Note: these estimations are still preliminary (waiting for feedback from unit suppliers) Note: these estimations are still preliminary (waiting for feedback from unit suppliers) and do not include instrument contingency - up to 15 kg .and do not include instrument contingency - up to 15 kg .

More reliable figures can be provided following feedback from unit suppliers.More reliable figures can be provided following feedback from unit suppliers.

Specified/Predicted

Allocated Margin

DES 2.5 3.0 0.5Rx 1.0 1.5 0.5RDS SUBTOTAL 3.5 4.5 1.0TFE 2.0 2.5 0.5ANTENNA 1.8 2.0 0.2ELECTRONICSSUBTOTAL

7.3 9.0 1.7

HARNESS 0.7 0.75 0.05THERMAL CONTROL 1.8 2.0 0.2

TOTAL 9.8 11.75 1.95


• Top flor Area [mm^2]

Payload Component

Dim Envelope

Total Dim W MLI

SHARAD

SHARAD UNIT

Antenna (ANT) 112500 130625

L 450 475

W 250 275

H 100 125

Transmitter (TX) 67500 83125

L 450 475

W 150 175

H 100 125

Reciever & Digital Electronics (RDS)55000 67375

L 220 245

W 250 275

H 200 225

Cabling 0

Thermal Control

Therma DoublerL TBDW TBDH TBDRadiatorL TBDW TBDH TBDMiscellanea TBD

Envelope reference dimensionsEnvelope reference dimensions


• Instrument Budget

• Heaters Budget

Power BudgetPower Budget

Allocated DES 30.0 Rx 9.0 RDS SUBTOTAL 39.0 TFE 13.0 TOTAL

51.0


Design and development Design and development approachapproach- - Model philosophyModel philosophy- Testing and verification approach- Testing and verification approach- Ground testing approach- Ground testing approach

R. CROCIE. ZAMPOLINI FAUSTINI

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: Introduction (1)D&D Approach: Introduction (1)

• SHARAD Design and Development will be based on the sequencing of the following four project phases:

• Concept Definition: devoted to system level architecture definition and trade-offs

• Design & Breadboarding: devoted to detail system definition and breadboarding of critical items

• EM Development: devoted to development, manufacturing and testing of a complete Engineering Model to validate instrument design and allow a ProtoFlight development.

• PFM Development: devoted to development, manufacturing and testing of a fully qualified Flight Model on the basis of the proven design.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: Introduction (2)D&D Approach: Introduction (2)

• Major project Milestones intermediate to Instrument Delivery are:

• Instrument Concept ReviewPurpose: to review instrument concept

• Instrument Preliminary Design ReviewPurpose: to review instrument design and release the electrical and mechanical detailed design for the EM development.

• Critical Design ReviewPurpose: to freeze instrument design and to release Proto-Flight Development.

• Instrument Delivery Acceptance ReviewPurpose: to review the results of PFM testing in view of its integration in the satellite

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: Model PhilosophyD&D Approach: Model Philosophy

• Payload Fit Check Template (PFT)

Used for development testing of SHARAD Mechanical Interfaces with the Spacecraft

• Interface Engineering Model (IEM)

Used for development testing of SHARAD interfaces with the Spacecraft. The IEM will be the first electrical model and will be used to provide verification of the electrical and (tentatively) mechanical interfaces with the Spacecraft. The IEM will be electrically tested for proper operation of the external interfaces only.

• Engineering Model (EM)

Used for development testing of SHARAD technical and engineering parameters. It is electrically and mechanically representative of the instrument. The EM will be the model that fully supports all Sounder operation and will be used to provide verification of these functionality’s.

• Protoflight Model (PFM)

Used for verification of SHARAD technical and engineering parameters. The PFM will be fully flight standard. It will be subjected to qualification level and duration testing.


START

MGSE EGSE

Integration

Integration at S/C level

Incoming Incoming

Installation

Panel

Incoming

TX &Imped. Match. S/S

Incoming

Receiver &Digital S/S

Incoming

Incoming

Miscellanea

Radar Electronicstest

Shipment to S/C Incoming

Antenna S/SIncoming

ContinuityTest

Radar Checkout +

Continuity Test

ORBITERVerification &

Prelaunch Phase

Electrical I/FOperational CharacterisationEMC PerformanceTherm S/C Reference

D&D Approach: Integration/Testing & D&D Approach: Integration/Testing & Verification FlowVerification Flow

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: Testing & Verification notes D&D Approach: Testing & Verification notes (1)(1)

• PFM subsystems will undergo to the qualification steps through Electrical, Functional, EMC, Thermal-Vacuum, Vibration tests.

• At instrument integrated level the following set of tests will be performed:

• Electrical I/F

• Operational

• Characterisation/Calibration

• EMC (reduced Set)

• Inital Performance Tests

• Thermal Cycle

• Final Performance Tests

• S/C Reference Tests (to be used as future reference at satellite level)

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: Testing & Verification notes D&D Approach: Testing & Verification notes (2)(2)

• PERFORMANCE VERIFICATION (i.e. assessment on the capability to detect subsurface features) will be performed through MEGS device.

• Performance is verified at ambient before (IPT) and after (FPT) thermal cycling, and a reduced set of tests will be performed during the thermal.

• Reference S/C test will be used as checkout mean to verify instrument operation during ORBITER integration/verification phases.

• A continuity test (injection of electrical signal) is foreseen to check integrity (electrical continuity) of antenna at several steps of the integration process. Feasibility of test is to be checked wrt antenna design.


Design and development Design and development approachapproach- - Calibration and validationCalibration and validation

R. CROCIE. ZAMPOLINI FAUSTINI

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: ValidationD&D Approach: Validation

• Two different validation steps are envisaged:

• On-ground Validation/VerificationTo validate the instrument performance, echoes from MARS will be simulated both in close loop configuration (starting from the TX signals) and in open loop configuration (using mathematically simulated echoes)

• In-flight ValidationA limited amount of raw data (Individual Echoes) will be acquired (in selected Orbits) together with the processed data and transmitted to the ground to check if the instrument is working as expected

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: Validation - EGSE (1)D&D Approach: Validation - EGSE (1)

• Basically the SHARAD EGSE shall be able to perform the following functions:

• Instrument powering and switch-on/switch-off procedure

• Generation and simulation of the instrument interfaces with the Spacecraft (Command & Control function) including the acquisition of the Telemetry Packets and their processing

• Instrument RF output signal detection, storage and processing

• Instrument RF input signal simulation, generation and injection

• Man-Machine Interface (MMI)

• Automatic Test Sequence Generation and Management.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: Validation - EGSE (2)D&D Approach: Validation - EGSE (2)

• The EGSE will be composed essentially by:

• Power Distribution Unit (able to work both at 220/240 Volt 50/60 Hz and at 110 V 60 Hz)

• S/C Interface Simulator

• Instrument I/F Simulator

• Mars Echoes Generator Subsystem (MEGS)

• Timing Generator

• Management PC

• Post Processing PC

• Radio Frequency Front End Electronics (RF-FEE) to simulate the Antenna


MANAGEMENT PC

SCIENCE DATA

Clock

TimingSignal

TM

TC

TX Chain Evaluation DES

TX

RX

MARSECHOES

GENERATOR

POST PROCESSING PC

DATA ACQUISITION&

MASS STORAGE

15 25MHz

COMMAND&

CONTROL(Including S/C SIMULATOR)

Timing

SHARADDAC

ADC RF-FEE

Clock

D&D Approach: Validation - EGSE (3)D&D Approach: Validation - EGSE (3)


Mars Echoes Generator Mars Echoes Generator SystemSystem

RF-FEERF-FEE

ADCADCInputInput

BufferBufferFFTFFT

MarsMars

TransferTransfer

FunctionFunction

IFFTIFFT DACDACOutputOutput

BufferBuffer

GalacticGalactic

NoiseNoise

TXTX RDSRDS

MEGS: Mars Echoes Generator MEGS: Mars Echoes Generator

Timing Generator Timing Generator Timing SignalsTiming Signals

Reference FrequencyReference Frequency

SHARAD SHARAD

Simulated EchoesSimulated Echoes

(Open Loop)(Open Loop)

D&D Approach: Validation - EGSE (4)D&D Approach: Validation - EGSE (4)


Sounder System Equation

Define Parameters to be

calibrated

MeasurementStrategy

Ground Processor

In-FlightMeasurements

Pre-FlightCalibration

PerformancePrediction

CalibratedProducts

• The scientific Calibration of the Instrument will be performed in two steps:

• ON GROUND CALIBRATION (PRE-FLIGHT CALIBRATION)

• IN-FLIGHT CALIBRATION

• SHARAD calibration approach:

D&D Approach: CalibrationD&D Approach: Calibration

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: CalibrationD&D Approach: Calibration

• Parameters can be measured, either directly or by calculation, at the following stages:

• 1. Component Level

• 2. Unit Level

• 3. Subsystem Level

• 4. System Level

• 5. During operations on orbit.

• Testing and calibration of key sounder parameters must be done at temperature levels which are representative of the expected in flight temperatures.

• Each parameter measurement is listed along with the variable affecting its estimated value, where it is measured and the frequency of their measurements.

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: On Ground Calibration (1)D&D Approach: On Ground Calibration (1)

• The parameters that will be calibrated on-ground (pre-flight calibration) can be divided in four main groups:

• 1. TX Chain Parameters Peak Power level, Pulse Length, BW, CF, Slope, Ripples, Group Delay, etc.

• 2. RX Chain ParametersMax Gain, NF, Ripples, Group delay, etc.

• 3. End to end ParametersSystem Impulse response, Ripples, etc.

• 4. Reference Oscillator Frequency.Accuracy, stability, warm-up time, etc.


• At System Level the configuration of the instrument will be the following one:

• Fully integrated and tested Instrument on panel inside the Thermal Chamber

• Antenna Subsystem represented by a the RF-FEE (RADIO FREQUENCY FRONT END ELECTRONICS) dummy load

• Relevant EGSE

• Standard instrumentation


RRFF--FFEEEE

AADDCC

DDAACC

TTXX RRDDSS

SSHHAARRAADD EEGGSSEE

TTiimmiinngg GGeenneerraattoorr TTiimmiinngg SSiiggnnaallss

RReeffeerreennccee FFrreeqquueennccyy

SSHHAARRAADD

MEGS

MARS ECHOES

GENERATOR S/S

S/C

INTERFACE SIMULATOR

TC

TM

THERMAL CHAMBER

D&D Approach: On Ground Calibration (3)D&D Approach: On Ground Calibration (3)


• The overall procedure for calibrating SHARAD at system level will be to:

• 1 – Acquire initial SHARAD calibration parameters at ambient temperature prior to calibration (INITIAL REFERENCE TEST)

• 2 – Thermal stress cycle SHARAD in a non-operative mode prior to calibration (TBC).

• 3 – Thermally stabilize SHARAD at the highest operative temperature and obtain the calibration parameters after SHARAD has stabilized in temperature.

• 4 – Lower the temperature by TBD Degrees Centigrade and after thermal stabilization acquire the calibration parameters.

• 5 – Repeat the above process until the calibration parameters at the final lower temperature of TBD Degrees Centigrade is obtained.

• 6 – Acquire SHARAD calibration parameters at ambient temperature (FINAL REFERENCE TEST).


Temp

T5°C

T2°C

T4°C

T3°C

T1°C

T6°C

time

TBD TBD TBD TBD TBD TBD

D&D Approach: On Ground Calibration (5)D&D Approach: On Ground Calibration (5)

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder D&D Approach: In Flight CalibrationD&D Approach: In Flight Calibration

• The H/W distorsions (including Antenna) will be calibrated acquiring unprocessed echoes from very flat surfaces according to a pre-defined procedure every TBD orbits.

• These periodic calibration activities will include:

• Noise characterization: collection of raw data in receive-only mode, to characterize the noise environment, every TBD orbits.

• Transmit/Receive antenna Radiation Factor using raw data collected in Calibration Mode over sufficiently smooth surfaces so that radar pulse reflection can be considered specular.

• Transfer function/impulse response evaluation

• All the above mentioned measurements will be compared/fused with all the output of the on-ground calibration to obtain the final calibrated products.


SHARAD Parameters Measurement Strategy

Parameter Variables Stage Frequency

TX Chain Parameters Temperature Frequency

Unit/Subsystem System

Once per stage

RX Chain Parameters Temperature Frequency

Unit/Subsystem System

Once per stage

End to end Parameters

Temperature Frequency

System Once per stage

Reference Oscillator Frequency

Temperature Component

System Once per stage

Transmit Power and Antenna Radiation

Factor

Temperatures Frequency

System (TBC)

In-Flight

Once

Periodic

Receiver Coupling factor and Gain

Temperatures Frequency

System (TBC)

In-Flight

Once

Periodic

Transfer Function Temperatures

Frequency

System

In-Flight

Once

Periodic

D&D Approach: CalibrationD&D Approach: Calibration


Management and Management and scheduleschedule

G. BRACONI

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder SHARAD - Team CompositionSHARAD - Team Composition PROGRAM

MANAGER

BRACONI

CONTRACTMANAGER

MURATORI

PRODUCTASSURANCE

MONTANARI

PROJECTCONTROL

FORASTIERI

SECRETARY

ROLANDO

PROJECTMANAGER

ZAMPOLINI

SYSTEMENGINEERING

DESIGNENGINEERING

ENGINEERINGVERIFICATION

MISSIONENGINEERING

ENGINEERINGCOORD. & DIR.

ZAMPOLINI

MECHANICAL& THERMAL

MARCOZZI

ELECTRICALDESIGN

CROCI

EMC

CROCI

I/F's

CROCI

DES

BERNARDINI& MAPPINI

RF

CROCI

PSS

CROCI

EGSE

TBD

ANTENNA

NOSCHESE

AIV/AIT

TBD

PERFORM.ANALYSIS

MARINO

SHARAD PERSONNEL

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder SHARAD - ScheduleSHARAD - Schedule

ID Nome attività Durata Inizio Fine1 Instrument Prel. Doc. (IFRD, EIP) 72 g 01/11/01 08/02/02

2 Instrument Doc (IFRD, EIP) ApprovedVersion 95 g 11/02/02 21/06/02

3 System/Subsystem Specs Issue 1 31 g 01/02/02 15/03/02

4 EGSE Preliminary Specs 43 g 01/03/02 30/04/02

5 System/Subsystem/EGSE Specs 38 g 01/05/02 21/06/02

6 PDR 1 g 24/06/02 24/06/02

7 Antenne Baseline Finalization 41 g 01/02/02 29/03/02

8 Antenna Specs Issue 1 44 g 01/04/02 30/05/02

9 S/W 425 g 02/05/02 17/12/03

10 IEM S/W 152 g 02/05/02 29/11/02

11 EM S/W 120 g 02/12/02 16/05/03

12 Final S/W 153 g 19/05/03 17/12/03

13 EGSE 282 g 02/05/02 30/05/03

14 IEM EGSE (incl. SE supplied by LMA) 152 g 02/05/02 29/11/02

15 Instrument EGSE 195 g 02/09/02 30/05/03

16 P/L Fit Check Template 153 g 02/05/02 02/12/02

17 RDS Mechanical Design & Mfct 130 g 02/05/02 30/10/02

18 Tx Mech. Design & Mfct 130 g 02/05/02 30/10/02

19 PFT Mech. Integration 22 g 31/10/02 29/11/02

20 PFT Delivery 1 g 02/12/02 02/12/02

21 IEM 197 g 02/05/02 31/01/03

22 IEM RDS Electrical Design & Mfct 152 g 02/05/02 29/11/02

23 IEM Test 45 g 02/12/02 31/01/03

24 RDS/TX/Antenna PDR 1 g 22/07/02 22/07/02

25 RDS/TX/Antenna PDR Close out 1 g 20/09/02 20/09/02

26 Sub-co CDR 1 g 31/03/03 31/03/03

27 I/F CDR 1 g 02/06/03 02/06/03

28 Sub-co CDR Close out 1 g 15/07/03 15/07/03

24/06

02/12

22/07

20/09

31/03

02/06

15/07

O N D G F M A M G L A S O N D G F M A M G L A S O N D G F M A M G L A S O2001 2002 2003 2004

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder SHARAD - ScheduleSHARAD - Schedule

ID Nome attività Durata Inizio Fine29 EM 369 g 02/05/02 30/09/03

30 EM RDS Electrical Design & Mfct 217 g 02/05/02 28/02/03

31 EQM Tx Electrical Design 238 g 02/05/02 31/03/03

32 DES Test 65 g 03/03/03 30/05/03

33 Tx Test & Qualification 65 g 01/04/03 30/06/03

34 EM Integration 65 g 01/07/03 29/09/03

35 EM Delivery 1 g 30/09/03 30/09/03

36 PFM 506 g 25/06/02 01/06/04

37 Long Lead Items Procurement 180 g 23/07/02 31/03/03

38 Long Lead Items Proc. Completion 87 g 01/04/03 30/07/03

39 RDS Mfct 87 g 01/04/03 30/07/03

40 RDS Completion 175 g 31/07/03 31/03/04

41 TX Mfct 87 g 01/04/03 30/07/03

42 TX Completion 175 g 31/07/03 31/03/04

43 Integration & Test 40 g 01/04/04 26/05/04

44 PFM Delivery 0 g 01/06/04 01/06/04

45 Antenna Develop. & Test (TBC pending baseline def.) 506 g 25/06/02 01/06/04

46 Antenna Delivery 0 g 01/06/04 01/06/04

30/09

01/06

01/06

O N D G F M A M G L A S O N D G F M A M G L A S O N D G F M A M G L A S O2001 2002 2003 2004

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder SHARAD - ReceivablesSHARAD - Receivables

• Receivables:

• Spacecraft Simulator

• I/F Components Kits (TBC)•LVDS Driver/Receiver•Temperature Sensors (AD 590)•Heaters?•Others?

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder SHARAD - DeliverablesSHARAD - Deliverables

• Deliverables:

• Payload Fit Check Template (PFT)

• Interface Engineering Model (IEM)

• Engineering Model (EM)

• Protoflight Model (PFM)

• Documentation requested by the project shall be discussed


Product AssuranceProduct Assurance(Mission Assurance)(Mission Assurance)

G. MONTANARI

SHARAD: MARS 2005 Shallow Sounder SHARAD: MARS 2005 Shallow Sounder SHARAD - PA ManagementSHARAD - PA Management

• Alenia Spazio (ALS) will guarantee the Customer that a PA programme will be developed and implemented during all project phases. The PA programme will cover all the Quality disciplines (i.e. Dependability, Safety, SWPA, Quality Assurance, EEE Parts Quality, Materials and Processes Selection).

• The SHARAD PA Programme will be based on the document “PA Plan for ASI Unmanned Programs” PLN-DQL-00-01 Issue A which in general meets the ECSS-Q-xx specifications).

• Upon receipt of specific SHARAD PA requirements, a dedicated PA plan may be prepared, if requested by the Customer.

• Basically the PA Plan will be the starting point of negotiation versus the Customer PA Requirements. A Compliance Matrix will establish and trace the ALS compliance to the Customer PA requirements.


• Same approach will be taken for the Subcontractors’ management. The ALS PA Plan will be flown-down onto them to establish a common PA policy.

• Similar Compliance Matrix will be the answer from the Subcontractor and its approval will define the PA Program applicable throughout the Program duration


• A Programme PA Manager will be designated for Flight and Ground segment, and he will co-ordinate the activities between his organisation and the Customer, and between his organisation and the Subco for all the PA Tasks.

• The PA Program will be applied to each SHARAD phase:

• Equipment / payload Design

• Equipment Manufacturing

• Equipment testing for Acceptance / Qualification

• Equipment Delivery

• Payload AIT

• Payload Delivery


• Since the beginning of the design phase, the PA program will be developed with the concurrence of the following disciplines and their specific tasks:

• DEPENDABILITY > Reliability Analysis, FMECA, Radiation Analysis, Parts Stress Analysis, Single Point Failure (SPF) List (this may be part of the FMECA)

• SAFETY > Safety Submissions according to Ariane User’s Manual or any other launcher requirements

• EEE PARTS > ALS policy is based on the maximum use of Grade 2 parts, under condition that the equipment reliability/radiation/end-of-life analyses show that these requirements are met. If not, Grade 1 parts will be used as long as necessary to meet the requirements. Parts will be authorised via PAD approval and tracked via Declared Component List (DCL) at equipment level.


• MATERIALS & PROCESSES > Maximum use of already qualified Mat & Pro; control of the qualification status of new technologies/materials/processes. All data concerning Mat&Pro are regularly provided to the Customer via the equipment Mat & Pro Lists (DML, DPL).

• SWPA > Participation in the design, development, and test activities of the software products, with special emphasis assigned to the control of SW anomalies.

• QUALITY ASSURANCE > Participation in the design, manufacturing and test activities of the hardware products. This will be achieved through in-process quality inspections and via Mandatory Inspection Points (MIP) with the Customer involvement. Non-conformances control is applied in all phases of the program.


• PA disciplines will be continuously involved throughout the program duration and will review the documentation when issued by the Subcontractors. The documentation in charge to PA will be issued at upper level (P/L for SHARAD), in accordance with the reviews indicated in the SoW.

• The purpose is to verify the design by means of Design Reviews according to the milestones defined by the Customer.


• The PA team will issue the requested documentation according to the objectives of the design/manufacturing/testing delivery review(s):

• the aim of initial design review(s) is to demonstrate that the requirements can be met, and to identify, in the early phase, any critical items to be controlled with dedicated program; to highlight any difference Vs the std EEE parts, Materials & Processes, or to propose and control any qualification of new technology needed.

• further design/manufacturing/testing/delivery review(s) will be supported by updated documentation to demonstrate the satisfactory control and closure of the above activities, and to give confidence the hardware associated to the review can be either manufactured, or tested or delivered to the next user.


• Quality Assurance provisions will be implement for procurement activity (EEE parts, Mat &Pro, etc.), during the manufacturing of the equipment, and during AIT activity.

• Full Quality Control Provisions will be applied from the Engineering Qualification Model (EQM) onward, without formal MIP with the Customer but applying internal inspections only.

• For PFM production full quality control will be envisaged including traceability and formal MIP.

• Non Conformance Report (NCR) system will be implemented. Notification to the Customer of major non-conformances will start from Initial Functional Test onward. Electronic NCR system has been developed by ALS based on Lotus Notes Software.

• Testing activity at any level will be based on a Test Readiness Review (TRR) which will formally authorise the test campaign to start.


• The performance of the product at the end of the test campaign will be reviewed in the Test Review Board (TRB), where test report and all supporting test data will be analysed.

• The consent to deliver any item or sub-assembly will be managed by a Delivery Review Board (DRB), where the acceptability of the hardware and associated documentation will be stated. The delivery will be based on the review and approval of the relevant End Item Data Package (EIDP).

Documents

SHARAD: MARS 2005 Shallow Sounder SHARAD: SHALLOW SOUNDER Science & Technical Meeting Rome, 19 - 20 - 21 March 2002