Research
InSAR orbital correction from InSAR-GPS integrationThe principal limitations of Interferometric Synthetic Aperture Radar (InSAR) to measure subtle, long-wavelength deformation are uncertainties associated with the satellite orbits. We propose a method to remove orbital phase errors from the InSAR data by integrating the InSAR time-series with continuous GPS time-series. We model the along-track variation of the baseline errors as second order polynomials and estimate the coefficients using the continuous GPS. We apply this method to a 600 km-long region encompassing the Basin and Range and the Eastern California Shear Zone. Comparison of the corrected InSAR velocities with independent GPS data shows that this method removes the long-wavelength InSAR error. The InSAR data reveal a region of rapid velocity change across the Hunter Mountain Fault. We model the deformation as inter-seismic elastic strain accumulation across a strike-slip fault. The modeling suggests a fault slip rate of 4.9 ± 0.8 mm/yr and a locking depth of 2 ± 0.4 km. The shallow locking depth suggests that the Hunter Mountain fault is a transfer fault between low angle normal faults in the area.
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| InSAR velocity map across the Basin and Range and horizontal velocity of PBO continuous GPS [Bennett et al., 2003]. |
