Nonlinear Kalmanfilter phase unwrapping algorithm based on the terrain
Man Yan1,2, Defa Hu3
COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(12A) 240-244
1School of Computer Engineering, Weifang University, Weifang 261061, Shandong, China
2School of Information Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, Shandong, China
3School of Computer and Information Engineering, Hunan University of Commerce, Changsha 410205, Hunan, China
Phase unwrapping is one of the key steps in InSAR data processing. In condition of steep terrain, excessive stripes reduce the conventional phase unwrapping algorithms’ implement, resulting in error propagation of unwrapping phase. Therefore, this paper presented a nonlinear Kalman filter phase unwrapping algorithm based on terrain. This algorithm uses local fringe frequency estimation as input control variable. Chirp-Z transform is added into Fourier transform in local frequency estimation, and this improves the unwrapping result accuracy. Results obtained with simulated and real data validate effectiveness of proposed method through analyzing and comparing with Kalman filter method, nonlinear Kalman filter method and quality map guiding method.