A Satellite Selection Algorithm for GNSS-R InSAR Elevation Deformation Retrieval

The global navigation satellite system (GNSS) reflectometry synthetic aperture radar (SAR) interferometry (GNSS-R InSAR) system enables elevation deformation retrieval using a single satellite. However, variations in bistatic configurations and the generally low accuracy of most satellites necessitate a refined satellite selection method. Thus, this letter proposes a satellite selection algorithm for GNSS-R InSAR, aiming to optimize satellite selection and data acquisition time to improve the precision of elevation deformation monitoring. First, the interferometric phase model based on the repeat-pass concept was established using GPS L5 signals. Second, a satellite selection algorithm was proposed that incorporates constraints on resolution cells, spatial baseline, and phase sensitivity for elevation deformation, derived from an analysis of the repeat-pass spatial baseline of GNSS satellites, interferometric phase sensitivity, and the maximum deformation range. Third, 24 sets of repeat-pass data were collected, and the experimental results validate the effectiveness of this single-satellite selection approach.