Toward full exploitation of coherent and incoherent information in Sentinel‐1 TOPS data for retrieving surface displacement: Application to the 2016 Kumamoto (Japan) earthquake

Abstract

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.

The 2016 M7 Kumamoto, Japan, Earthquake Slip Field Derived From a Joint Inversion of Differential Lidar Topography, Optical Correlation, and InSAR Surface Displacements

“…We use the triangular-based fault resolution algorithm developed by Lohman and Simons (2005) and McGuire et al (2015) to downsample the lidar and optical data sets. The InSAR imagery from Jiang et al (2017) is already downsampled to a suitable resolution. Table S2 shows the number data points after downsampling, and Figures S1-S2 show the slip inversion results with the downsampled data.…”

“…Increasing the amount of regularization (i.e., higher λ) decreases the maximum slip for both sets of earthquake source inversions (Figure 4b). In contrast, the optical and InSAR (Jiang et al, 2017) data sets can be well modeled with a single curving fault. This may reflect that the greater density of differential lidar topography near the fault require more concentrated slip and a higher slip magnitude.…”

Deriving Spatio-Temporal Development of Ground Subsidence Due to Subway Construction and Operation in Delta Regions with PS-InSAR Data: A Case Study in Guangzhou, China

“…Topographic phase contributions were removed from each point target (PT) by the 30 m Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). Satellite orbital errors often cause phase errors, thereby producing low-frequency fringes [34][35][36][37]. We re-estimated the baseline parameters from the unwrapped point phase and the DEM heights.…”

Landslides and Subsidence Assessment in the Crati Valley (Southern Italy) Using InSAR Data

“…SAR datasets have been widely employed to analyze different types of ground movements, such as subsidence [6][7][8][9], landslides [10][11][12], deformations associated with active and quiescent faults [12][13][14][15], and volcanic activity [16,17]. Discrimination between the different causes of ground displacement that take place in an area of interest is a challenging task.…”