Toward full exploitation of coherent and incoherent information in Sentinel-1 TOPS data for retrieving surface displacement: Application to the 2016 Kumamoto (Japan) earthquake
Date of Issue2017
Earth Observatory of Singapore
Sentinel-1's continuous observation program over all major plate boundary regions makes it well suited for earthquake studies. However, decorrelation due to large displacement gradients and limited azimuth resolution of the Terrain Observation by Progressive Scan (TOPS) data challenge acquiring measurements in the near field of many earthquake ruptures and prevent measurements of displacements in the along-track direction. Here we propose to fully exploit the coherent and incoherent information of TOPS data by using standard interferometric synthetic aperture radar (InSAR), split-bandwidth interferometry in range and azimuth, swath/burst-overlap interferometry, and amplitude cross correlation to map displacements in both the line-of-sight and the along-track directions. Application to the 2016 Kumamoto earthquake sequence reveals the coseismic displacements from the far field to the near field. By adding near-field constraints, the derived slip model reveals more shallow slip than obtained when only using far-field data from InSAR, highlighting the importance of exploiting all coherent and incoherent information in TOPS data.
Geophysical Research Letters
© 2017 American Geophysical Union. This paper was published in Geophysical Research Letters and is made available as an electronic reprint (preprint) with permission of American Geophysical Union. The published version is available at: [http://dx.doi.org/10.1002/2016GL072253]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.