Welcome to MDA

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RADARSAT-2 Radargrammetry
MDA Proprietary
Marco van der Kooij Director, GSI Services MDA
Geospatial Services mvanderkooij_at_mdacorporation.co
m 613-727-1087
Alaska DEM Workshop July 22-23, 2008 Anchorage,
Alaska
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Contents

• Introduction, GSI Services, Radarsat-2
• ERS InSAR example, N-Canada
• Radarsat-2 Radargrammetry validation experiment
• Strengths of Satellite radar solution

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MDA Geospatial Services

• Data Business
• Service Business (after acquisition of Vexcel
  Canada in 2007)
• InSAR deformation Services (Oil and Gas, Mining)
• Digital Elevation Models
• Land based services
• Maritime services

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RADARSAT-2Testing and Launch

• Satellite completed July 24 2007
• Shipped to the launch site (Baikonur, Kazakhstan)
  November 12, 2007
• Successful launch and deployment December 14,
  2007
• Commissioning phase completed April 15, 2008

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RADARSAT-2 Mission Overview

• Co-funded by Canadian Space Agency (CSA) and
  MacDonald Dettwiler (MDA)
• Data continuity from RADARSAT-1
• all RADARSAT-1 imaging modes supported
• plus many additional capabilities
• Mission duration 7 years
• Designed, built, operated and owned by MDA

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RADARSAT-2 Beam modes and features

• High resolution
• 3 m
• multi-look 10 m
• SpotLight
• Polarimetric modes
• single/dual polarization
• quad-pol
• Right and left-looking capability
• Enhanced ground system providing
• efficient satellite tasking
• (12 - 24 hours routine)
• faster data processing
• Calibrated data

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RADARSAT-2 Imaging Modes
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Vancouver, Ultra-fine
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Detail, Vancouver Airport, Ultra-Fine
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Polarization Concepts

• For imaging radar applications, the polarization
  state of the radar wave is defined
  with-respect-to the Earths surface
• Co-polarized
• transmit/receive horizontal (HH)
• transmit/receive vertical (VV)
• Cross-polarized
• transmit horizontal, receive vertical (HV)
• transmit vertical, receive horizontal (VH)

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Fine Quad PolarimetryDevon Island
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MDA GSIDEMs

• InSAR
• Atlantis Scientific / Vexcel InSAR software for
  elevation mapping
• MDA InSAR toolkit for elevation mapping
• Northern Canada, Baffin Island, 150,000 scale
  mapping, 7 m vertical accuracy for low to
  moderate terrain
• Radargrammetry
• Commercial off-the-shelf
• Vexcel Radargrammetry
• Finishing, based on SRTM methodology but further
  automated
• Photogrammetric base mapping editing tools and
  expertise

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ERS Tandem InSAR DEMs Baffin Island7 m LE90
for low to moderate topography

• Y. Robitaille (PM, CTI) The best 150,000
  scale DEMs we have ever seen. Vertical accuracy
  is 7 m LE90
• Elevation data available to the public through
  Can. Gov. portal

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Radar across Track Geometry
Layover
Shadow
Projection of Radar Image
Shadow behind peaks
Mountains overlay lake
Lake
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Radar Triangulation (2-D)
Baseline
Height
Across Track
2-D Coordinate System
2-D coordinates determined by intersecting arcs
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Across Track Geometry - Single Stereo Pair
100 km
800 km
50 km
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RADARSAT-2 Mapping Flexibility This pattern is
repeated every 24 days
MF
MF
MF
Repeat paths of the satellite...
S7
S7
Three stereo models
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Radargrammetry with Radarsat-2(compared with
Radarsat-1)

• Higher resolution, more looks better matching,
  more features
• Multi-look fine (9 x 9 m, 4 looks)
• Ultra-fine (2 m x 3 m, 1 look)
• Spotlight (2 m x 1 m, 1 look)
• More favourable stereo geometry for high
  resolution modes (full flexibility of incidence
  angles (30-50 deg)
• Repeat pattern (24 days) is suitable for stereo
  angles
• The combination of left and right looking modes
  improve the acquisition capacity and geometry
  (potential of 4 azimuth look directions
  (ascending/descending and left/right)
• Orbit accuracy improved (GPS). Reduced need for
  ground control points.
• Large acquisition capacity for commercial
  acquisitions (87.5 of capacity, 2360 scenes per
  day)

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Area of Interest

• Roughly centered on Morrison, Colorado
• Also the test site of other Digital Elevation
  Models (DEM) evaluations
• Benefit of multiple control and evaluation
  datasets

Denver
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
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Validation activity Radarsat-2 Radargrammetry

• R-2 DEM from 1 pair of UF
• Acquired April 1 11, 2008
• R-2 DEM from 1 pair of MLF
• Acquired March 1 11, 2008
• 42 National Geodetic Survey (NGS) benchmark GPS
  points collected (sub-meter accuracy) for QA
• USGS NED 10 m DEM
• SRTM 1 arc second and 3 arc second datasets

MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
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Accuracy Evaluation Specifics

• 43 NGS points were collected and 42 used
• 1 NGS point was removed due to obvious erroneous
  value
• 28 remaining points in terrain less than 20
  degrees
• 14 remaining points in terrain more than 20
  degrees
• (highlighted in green)

MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
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NGS Benchmark Data

• Reference data set for absolute vertical accuracy
  tests

MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
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Theoretical accuracy (LE90)based on Radarsat-1
measurements
Radarsat-1
Radarsat-2 Multi-Look-Fine
Radarsat-2 Ultra-Fine
Radarsat-2 Spotlight
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Theoretical accuracy (LE90)Compared with
Radarsat-2 measurements
Radarsat-1
Radarsat-2 Multi-Look-Fine
Radarsat-2 Ultra-Fine
Radarsat-2 Spotlight
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SRTM 90m
SRTM 30m
NED 10m
Ultrafine 30m
Multi-Look 30m
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
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Statistical summaryAbsolute accuracy (LE90)
LE90, abs (m) NED SRTM 30 SRTM 90 UF MF
           
lt 20 deg 7.03 6.3 18.7 13.0 9.7
gt 20 deg 11.1 15.7 30.5 20.5 18.2
All 8.2 14.0 22.0 19.3 16.1
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
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Statistical SummaryStandard Deviation of
Subtraction Images
NED SRTM 30 SRTM 90 UF MF
           
NED 7.75 11.16 7.07 7.61
SRTM 30 8.29 6.08 9.06
SRTM 90 9.34 11.42
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
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Improved accuracy

• Additional stereo pairs (ascending AND
  descending) to cover acquisition holes and for
  error reduction
• Automatic finishing methodology to filter
  outliers and apply water body flattening,
  drainage network consistency
• Photogrammetric editing techniques
• Use of higher resolution beam modes (Ultra-fine
  and Spotlight mode)

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Horizontal and vertical control

• Accurate orbit data (several m) allow absolute
  horizontal control of DEM
• Local sources of vertical control (e.g. NGS,
  Aster)
• Validation and local collaboration

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Acquisition approach for successful coverage of
slopes

• Prior modeling of layover, foreshortening,
  shadow.
• 1 ascending pair and 1 descending pair for each
  location Improved vertical accuracy
• Nearly constant, suitable incidence angle range
  (38-50 degrees) to optimize successful coverage
  of slopes
• For steeper terrain
• Additional smaller incidence angle pairs to
  maximize slope coverage
• Additional azimuth coverage from right looking
  modes if necessary
• Use of Spotlight mode for key targets (e.g. Mt.
  McKinley)

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Building of archive

• Currently no archive exists
• Archive can be built up quickly with Multi-look
  Fine, complemented with Ultra-fine and Spotlight
• Independent of cloud cover!
• Acquisition during winter and summer
• Large acquisition capacity

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Deliverables

• DSM (Digital Surface Model), spacing 10-30 m
• Ortho SAR images
• Breaklines
• Features
• Water bodies, rivers etc.
• Licensing
• DEMs negotiable
• Price lt 10 M

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Summary

• Radarsat-2 is a viable source of DEMs
• Radarsat-2 is reliable and with a very large
  capacity for mapping
• Potential collaboration for downlink and
  applications expertise at Alaska SAR facility
• Medium to high resolution source imagery
  (including Spotlight)
• MDA has experience in providing elevation data
  for Northern Canada for operational mapping
• Radarsat-2 could play a role in monitoring
  environment and for special applications (e.g.
  deformation monitoring)