Quantitative Analysis of SAR Image Geometric Distortion and Its Application in Deformation Rate Fusion Mapping

Abstract

InSAR technology has emerged as a powerful tool for the early identification and monitoring of geological hazards in the Loess Plateau. Since the SAR satellite adopts the range-azimuth two-dimensional side-looking imaging mode, the corresponding field area of the pixel will change with slope, aspect, and incident angle, especially in areas with severe changes in terrain and landforms, which causes serious area distortion, leading to abnormal deformation rate mapping. Considering the SAR imaging geometry, terrain slope and aspect conditions, this paper proposes a quantitative analysis method for accurate geometric distortion based on pixel area and corresponding field area and constructs a weighted fusion method based on distortion values for InSAR deformation rate maps in overlapping regions of adjacent tracks. Taking Lingtai County, Gansu Province as the research area and Sentinel-1 data as the research data, we utilize the SBAS method to process the Sentinel-1 data and estimate the deformation rate, and then use the geometric distortion value as a weight factor to estimate the fusion rate of the overlapping area of adjacent tracks. The results demonstrate that the weighted fusion method based on distortion values can achieve a high-quality mosaic effect of deformation rate maps of adjacent tracks, effectively improve the geometric distortion influence in deformation rate mapping, and the identification of geological hazards.

A GAN-based fast focusing method for circular SAR images

“…Synthetic aperture radar(SAR) [ 1 ] is a remote sensing technology based on phased-array radar knowledge, and it generates Earth details images by coherently integrating the motion of the radar platform with the reception of multiple radar echoes. SAR boasts the capability for imaging around the clock and under any weather conditions, which has led to its extensive application and recognized importance across diverse domains [ 2 ], including disaster monitoring [ 3 ], marine monitoring [ 4 ], resource surveying [ 5 ], and crop yield estimation [ 6 ]. However, inherent restrictions due to physical constraints and imaging parameters can affect the quality of SAR images, resulting in an out-of-focus radar image [ 7 ].…”