MAPPING AND EVALUATION OF LAND DEFORMATION WITH INSAR AND GNSS MEASUREMENTS NEAR HOUSTON, TEXAS, USA

This study used persistent scatterer (PS) interferometric synthetic aperture radar (InSAR) techniques to estimate land deformation near Houston area, Texas, USA, between 2017 and 2021. In order to improve the spatial resolution of the subsidence map, two spatial interpolation techniques, i.e., empirical orthogonal function (EOF) and Kriging, were used. The interpolated results were compared against that obtained from the co-located global navigation satellite systems (GNSS) observation stations. It was concluded that the time series and trend of PS agreed well with GNSS, and that interpolated maps of EOF and Kriging showed similar spatial patterns and good agreement in scatterplots against co-located GNSS stations. Differences in results between GNSS and InSAR may stem from: 1) the spatial variability of subsidence, and 2) difference in observation directions.