Tri-channel SAR-GMTI High-Speed Target Imaging and Motion Parameter Estimation Using KWT
Qian Jiang①; Su Jun-hai①; Li Liang-hai②; Xing Meng-dao①
①National Lab of Radar Signal Processing, Xidian Univ., Xi’an 710071, China; ②The 704th Institute of China Aerospace Science and Technology Corporation, Beijing 100076, China
Abstract：A parameter estimation method by imaging with the Keystone-Wigner Transform (KWT) for fast moving target is proposed. The radial velocity of fast moving target can cause the range walk and azimuth Doppler shift, so the accurate Doppler center can not be obtained only with interferometric phase, but with the range walk ratio of the target the Doppler ambiguity can then be resolved and the accurate Doppler center can be acquired. The along-track velocity of the fast moving target will result in the changing of the Doppler rate, and makes the moving target defocused in conventional SAR image. The Doppler rate can be attained with KWT after the range walk is removed, then the radial velocity can be obtained with the interferometric phase and following the along-track velocity of the target can be attained. The moving target indication is processed in the Dechirped domain, and in the case of acquiring the along-track velocity of the target both the PRF ambiguity and the phase ambiguity are taken into account, so the relocation and the velocity estimation of the fast moving target can be achieved. The processing result of measured data illustrates the effectiveness of the method.
2010, Vol. 32 
