Full-Angle DEM Generation Based on Repeat-Pass L-band CSAR Interferometry-Theory and Experimental Results

• Published in: IEEE sensors journal Vol. 24; no. 3; p. 1
• Main Authors: Li, Jianpeng, An, Daoxiang, Feng, Dong, Xu, Junyi, Chen, Leping, Zhou, Zhimin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-02-2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Algorithms; back projection algorithm (BPA); Circular synthetic aperture radar interferometry (In-CSAR); DEM extraction; DEM fusion; Digital Elevation Models; Interferometric synthetic aperture radar; Interferometry
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2023.3341421

In recent years, the generation of high-precision ground digital elevation models (DEMs) based on synthetic aperture radar interferometry (InSAR) technology has attracted wide attention. Compared with the traditional linear InSAR technique, a 360° aperture gives circular InSAR (In-CSAR) the capability to generate a full-angle DEM of the observed region. Due to the highly nonlinear platform trajectories, the back projection algorithm (BPA) is used to obtain the subimages and interferograms. In this paper, spectral characteristics of the BP-focusing subimages, including 2-D spectral ambiguity and space-variant spectral support, are derived in detail. Using these characteristics, an improved BPA to ensure the accuracy of the interferograms is proposed, which takes the shape and position of the subaperture into consideration. Without external DEM, an effective method of full-angle DEM generation is proposed for an airborne repeat-pass L-band In-CSAR system. Based on the weighted fusion of multiple observations, the proposed subaperture strategy can improve the accuracy of the full-angle DEM. The experimental results indicate that proposed strategy can generate more accurate DEMs (with an average error of 0.69 m). Moreover, the first real 360° DEM results acquired by our developed L-band In-CSAR system are given in this paper. The effectiveness and practicability of the proposed approach is verified with the processing results of simulation and real data.