Time-varying Baseline Estimation Method for FMCW InSAR
FU Xikai①②③ XIANG Maosheng①② WANG Bingnan①② JIANG Shuai①②③ YANG Yu①②③
①(Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China) ②(Science and Technology on Microwave Imaging Laboratory, Beijing 100190, China) ③(University of Chinese Academy of Sciences, Beijing 100049, China)
For airborne dual-antenna FMCW InSAR systems, the time-varying baseline can be considerably high due to its low flight height, atmospheric turbulence, location and attitude errors and low accuracy of MEMS IMU, seriously affecting the DEM accuracy. To deal with this problem, a time-varying baseline estimation method for FMCW InSAR system is proposed. Firstly, the time-varying baseline derivative for each range gate using single look complex image data is established, and the space-variant model in range direction is established. Then the horizontal and vertical time-varying baseline derivative obtained using random sample consistent method is integrated. Finally, the proposed method is implemented on real experimental FMCW InSAR data, the effectiveness of proposed method is validated by comparing estimated results with high accuracy POS information.
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