Lyons and Sandwell, JGR, 2003 Landers EQ Hector Mine EQ

forming interferogram

phase due to curved earth phase due to topography Perpendicular baseline MATTERS!

total phase

Phase from curved Earth

total phase

Critical Baseline

Phase from topography

phase minus spherical earth

How high is Toro Peak?

deformation and topography

Triggered slip on Southern San Andreas Fault

Need for Precise Orbits 1. proper focus 2. transform from geographic radar coordinates 3. image alignment 4. flattening interferogram Brute force algorithm given precise orbit subroutine pick target point fly satellite along orbit and identify point of closest approach (This is inefficient but computers are fast so don’t waste time coding.)

GMTSAR 2-pass processing no ground control seamless abutment of frames along track stacking for time series one master and many slaves primary, secondary, tertiary, image alignment ScanSAR Interferometry possible but not easy code needs refinement