landers hector mine eq - unavco · transform from geographic radar coordinates 3. image alignment...
TRANSCRIPT
Lyons and Sandwell, JGR, 2003
LandersEQ
Hector MineEQ
http://topex.ucsd.edu/gmtsar
forming interferogram
B = Bsin θ −α( )
B⊥ = Bcos θ −α( )
∂φ∂ρ
=−4πBλρ
cos θ −α( )sinθ
cosθ − ρb
)*+
,-.
φ − φe( ) ≅ −4πreBcos θ −α( )λρbsinθ
(r − re )
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
Lyons and Sandwell, JGR, 2003
LandersEQ
Hector MineEQ
Triggered slip on Southern San Andreas Fault
Need for Precise Orbits1. 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 processingno ground controlseamless abutment of frames along track
stacking for time seriesone master and many slavesprimary, secondary, tertiary, image alignment
ScanSAR Interferometrypossible but not easycode needs refinement