Mobile Multi-Sensor Geomatics (M2G) Systems – The New Trend in Mapping and GIS applications

Mobile Multi-Sensor Geomatics (M2G) Systems – The New Trend in Mapping and GIS applications

Dr. Naser El-Sheimy, PEng, CRCAssociate Professor and Interim Head Mobile Multi-Sensor Research Group

Chair FIG WG C5.3 “Integrated Positioning, Navigation and Mapping Systems” Vice Chair IAG WG Sc4.1 “Mobile Multi-Sensor System”

24/09/03

2 Mobile Multi-Sensor Systems Research Group

Contents

Mobile Multi-Sensor SystemsMotivation for their development

Components of MMS Examples of MMS

LandAirPortable

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Mobile Mapping Systems (MMS) Multi-sensor systems that integrate various

navigation and remote sensors on a common platform

Typical platforms are vans and airplanes

Capitalise on the strengths of the individual technologies to increase efficiency of data collection

Development motivated by demand for rapid and cost effective data acquisition systems and availability of integrated navigation systems (GPS/INS)

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Components of MMSSensors

Vehicles

ApplicationsMapping DTMEnvironmental Monitoring GISMachine Control Accident Investigation

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S-VHS S-VHS CameraCamera

INSINSGPS AntennaGPS Antenna

8 Digital8 DigitalCameraCamerass

Land Based Systems: The VISAT Van

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SVHSSVHSGPS AntennaGPS Antenna

INSINS

8 Cameras8 Cameras

The VISAT Van

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Post-Processing – GPS/INS Processing

The GPS and INS data is processed via Klman Filtering Integration processor to create a Georeferencing File that contains the system position and attitude at a frequency of 50 – 200 Hz.

GPS INS

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Post-Processing – Image Georeferencing

Each individual image is then tagged with a position and attitude based on the capture time. The result is a georeferenced image database.

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-1-0.8-0.6-0.4-0.2

00.20.40.60.8

1

0 20 40 60 80Check Point Number

Posi

tiona

l Err

or (m

) Northing Easting Height

-1-0.8-0.6-0.4-0.2

00.20.40.60.8

1

0 20 40 60 80Check Point Number

Posi

tiona

l Err

or (

m) Northing Easting Height

INS stand-alone mode GPS/INS mode

Horizontal VerticalSurvey Mode

Max Residual RMS Max Residual RMS

GPS/INS – Ideal Conditions 0.42 m 0.13 m 0.26 m 0.08 m

INS Only – Worst Case Conditions 0.87 m 0.29 m 0.50 m 0.19 m

Accuracy of the VISAT System

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Real Time Forest Fire Fighting (F3)

Real-time reporting of the exact situation of fires Assisting the Forest Fire Information Centers in accurately

assessing the fire Precisely directing water-bombers and fire-fighting crews

WADGPS

Thermal Thermal CameraCamera

WADGPSWADGPS

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F3 - Operational Overview

WADGPS

Water Bombers

Spotter aircraft

Hot spot/Fireis detected at Position ?

FFIS

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F3 – Prototype Hardware Components

INSINS

WA

DG

PS

Thermal Camera

Video CameraAHARS

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S-frame

INS b-frame

GPS antenna

R (t)bm

R Sb

ab

abGPS

S-frame

INS b-frame

GPS antenna

R (t)bm

R Sb

ab

abGPS

t t+1 t+n

F3 - System Concept

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Real-time Detection of Forest Fires and Hotspots

Original Thermal Images Detected Fires and Hotspots

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System TestingTest Area - Bowness Park Picnic Sites, Calgary

Target Hot Spots

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System Testing

Night Flight Test Path

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F3 System AccuracyHorizontal RMS of 8 m

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Backpack GPS/GIS Systems Advantages

Little skill required High absolute accuracy Possible integration

with other sensors, e.g. speech recognition and digital cameras, etc.

Disadvantages Not suitable in urban

centers or forested areas

Point information only

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Mobile Data Acquisition

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Portable MMS - System Overview (1)

Data Acquisition

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3-D coordinates

Anchor 1 Anchor 2Anchor 2

Image 1Image 1 Image 2Image 2

Portable MMS - System Overview (2)

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Attitude Sensor – Leica DMC

3 MEMs Accelerometers 3 Magnetic sensors Angle Accuracies:

Azimuth – 0.5° Roll/Pitch – 0.15°

3 cm 3 cm 1.5 cm Lightweight, low power consumption RS-232 Output

Leica DMC

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System ConfigurationSystem Configuration

Flash signal at time of exposure

GPS Antenna

Roll, pitch and azimuth angles

Logging Computer

Digital Camera

Digital Compass / Inclinometer

Takes digital images and stores them internally

Measures attitude angles

GPS Receiver Measures positions Time-tags attitude angles Marks times of exposures

Records continuous measurements of position and attitude angles Records times of exposures

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System Testing – Target Field

System testing over a “typical” urban environment

Surveyed using total station, GPS, close-range photo-grammetry

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Eastin

g

North

ing

Heig

ht

RMSE (m)

0.07 0.10 0.04

Mean (m)

0.01 -0.08 -0.03

(m) 0.07 0.06 0.03

Mapping Accuracy Absolute

accuracies similar to L1 RTK GPS

Much of the error – particularly in height – is a bias

Relative error is smaller

RMSE (m)

0.14 0.14 0.09

Mean (m)

0.10 0.05 -0.08

(m) 0.10 0.13 0.03

3 Images, 10-12 image point measurements

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Conclusions1. MMS are becoming an emerging trend because of : Market demands for efficient ways of data collection and A technology push due to new imaging and navigation hardware.

2. Multi-sensor systems are characterized by : Tight sensor integration during the measurement process

(synchronization on common platform). A total solution approach (no external control needed). Georeferencing by INS/GPS as the core mathematical technique.

3. Other Important aspects of MMS are : Data fusion with the goal of minimizing the total error budget. Implementation of MMS for real-time applications. Automation of post-mission processing be eliminating operator

interaction. Efficient manipulation of large data sets.

Documents

Mobile Multi-Sensor Geomatics (M2G) Systems – The New Trend in Mapping and GIS applications