An Adaptive Fake Permanent Scatterer Removal Algorithm Based on Direct Signal Reconstruction of Multiparameter Estimation for GNSS-InBSAR

Global navigation satellite system-based bistatic synthetic aperture radar interferometry (GNSS-InBSAR) system adopts a novel and integrated GNSS receiver, where the direct signal could be collected by the backlobe of the reflected antenna and would result in the fake permanent scatterers (PSs) in the single-channel data. Additionally, limited by the data amount, only one channel of data can be transmitted and signal processed. In this letter, an adaptive fake PS removal algorithm is proposed based on the multiparameter estimation direct signal reconstruction. First, the direct signal model considering the transmission link filter, the image offsets, the amplitude, and the phase of the image is established. Then, all these parameters are estimated based on the adaptive image information extraction. Finally, the direct signal is reconstructed to remove the fake PSs in the raw image results. The raw data of the Beidou navigation satellite is used, and the final experimental results indicated that the fake PSs in the SAR images can be completely removed, and the deformation retrieval accuracy of the interference area has improved by 63%.