InSAR Processing and Applications 1

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 3

InSAR Applications 1st InSAR missions SeaSat 1980 Since then ERS-1, JERS, RadarSat-1, ERS-2 … SRTM (Shuttle Radar Topography Mission) 4

InSAR Applications Airborne surveillance Deformation after natural disaster Changes in road conditions Planetary surface mapping 5

InSAR Applications Changes between two scenes (Coherent change detection) 6

InSAR Processing 3 Main processing steps (Satellite based processing) Data Search Data Processing Product Validations Subtle challenges based on platform and geometry 7

InSAR Processing – Data Search 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 8

InSAR Processing – Data Processing 9

InSAR Processing – Data Preprocessing Need two SLC SAR images Accurate position, collection geometry Data collection parameters (headers, etc.) 10

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 11

InSAR Processing – Interferometric Products Calculation of Interferogram Some parts of image may have “noise” segments 12

InSAR Processing – Phase Unwrapping Unwrapping may required advanced algorithms to ignore or work around issues 13

InSAR Processing – Phase Unwrapping Unwrapping may required advanced algorithms to ignore or work around issues 14

InSAR Processing – Geocoding Take DEM and put latitude/longitude/elevation 15

InSAR Processing – Challenges Many challenges at various steps Focus on two Speckle Layover/Shadowing 16

InSAR Processing – Challenges Speckle due to homogenous terrain scattering 17

InSAR Processing – Range Cell Resolution Slant range resolution cells independent of terrain 18

InSAR Processing Layover/Shadowing happen when terrain variation masks features 19

InSAR Processing – Other Platforms Experimental data has it’s own challenges 20

InSAR Processing – Other Platforms May have multiple returns Must choose the return that needs to be imaged 21

InSAR Processing – Other Platforms Actual created SLC images 22

InSAR Processing – Other Platforms Coherence Values 23

InSAR Processing – Other Platforms Interferometric Phase Products 24

InSAR Processing – Other Platforms DEM, Geocoded 25

InSAR Processing – Other Platforms Comparison between basic interpolation and InSAR terrain estimation 26