InSAR Processing and
Applications
Introduction
• William Blake – Aviation Software and Systems Engineer for the Weather
Radar Group
• With Garmin since 2010
• B.S. Co.E. in 2005 from University of Kansas
• Ph.D. E.E. in 2010 from University of Kansas
What do I do?
• Make pretty pictures
Where do I work?
• Depends on the day
InSAR Applications
• Many applications for InSAR Processing
• Fine resolution 3D imaging
• Monitoring of changes over time
InSAR Applications
• 1st InSAR missions SeaSat 1980
• Since then ERS-1, JERS, RadarSat-1, ERS-2 …
• SRTM (Shuttle Radar Topography Mission)
InSAR Applications
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Airborne surveillance
Deformation after natural disaster
Changes in road conditions
Planetary surface mapping
InSAR Applications
• Changes between two scenes (Coherent
change detection)
InSAR Processing
• 3 Main processing steps (Satellite based
processing)
• Data Search
• Data Processing
• Product Validations
• Subtle challenges based on platform and
geometry
InSAR Processing – Data Search
• Data search
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Need two complex SAR images
Not too far apart in space ~80 m (spatial decorrelation)
Not too far apart in time (temporal decorrelation)
Frequency band
Spatial resolution
InSAR Processing – Data Processing
InSAR Processing – Data Preprocessing
• Need two SLC SAR images
• Accurate position, collection geometry
• Data collection parameters (headers, etc.)
InSAR Processing – Coregistration
• Start with multiple SLC SAR images with
separate baselines
• Co-register images
• Coarse registration (Full pixel grid registration)
• Fine registration (Sub pixel grid registration)
• Resample one image to the other
• Calculate baselines
InSAR Processing – Interferometric Products
• Calculation of
Interferogram
• Some parts of image
may have “noise”
segments
InSAR Processing – Phase Unwrapping
• Unwrapping may required advanced
algorithms to ignore or work around issues
InSAR Processing – Phase Unwrapping
• Unwrapping may required advanced
algorithms to ignore or work around issues
InSAR Processing – Geocoding
• Take DEM and put latitude/longitude/elevation
InSAR Processing – Challenges
• Many challenges at various steps
• Focus on two
• Speckle
• Layover/Shadowing
InSAR Processing – Challenges
• Speckle due to homogenous terrain scattering
InSAR Processing – Range Cell Resolution
• Slant range resolution cells independent of
terrain
InSAR Processing
• Layover/Shadowing happen when terrain
variation masks features
InSAR Processing – Other Platforms
• Experimental data has it’s own challenges
InSAR Processing – Other Platforms
• May have multiple returns
• Must choose the return
that needs to be imaged
InSAR Processing – Other Platforms
• Actual created SLC images
InSAR Processing – Other Platforms
• Coherence Values
InSAR Processing – Other Platforms
• Interferometric Phase Products
InSAR Processing – Other Platforms
• DEM, Geocoded
InSAR Processing – Other Platforms
• Comparison between basic interpolation and
InSAR terrain estimation