Measuring near field coseismic displacements from SAR images: Application to the Landers Earthquake
Article first published online: 7 DEC 2012
Copyright 1999 by the American Geophysical Union.
Geophysical Research Letters
Volume 26, Issue 19, pages 3017–3020, 1 October 1999
How to Cite
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 16 JUN 1999
- Manuscript Received: 1 MAR 1999
We describe a procedure to compute SAR interferograms based on the compensation of the images' mis-registrations due to the ground deformation and on a specific adaptive filtering to improve the SNR in the measurement where displacement gradients are large. Applied to the Landers earthquake case, the registration reduces the phase noise by 20° (rms) near the fault and the interferogram reveals fringes that would not show out otherwise. The interferogram is validated by comparison, in the far field, with a GPS/EDM-based model. The inferred displacement field shows discontinuities that follow the fault within few hundred meters. Close to the fault the measured displacements differ significantly from that predicted by elastic modeling of the far-field data. Interferometry and measurements derived from the images' amplitude (offsets) appear to be complementary techniques providing original measurements that may help to reconcile seismological and geodetic models of coseismic deformation with measurements of fault-slip at the surface.