Research On Spaceborne Sar Azimuth Ambiguity Suppressing And Impacts On Insar Imaging

Spaceborne SAR has broad prospects in the realization of high-resolution imaging, wide swath imaging, etc. Spaceborne InSAR system consist of spaceborne SAR also get a strong potential in geological mapping, moving target detection and many other fields. Therefore, spaceborne SAR system attracts wide attention and recently becomes a focus in the radar area. However, in the spaceborne SAR design, there is a problem:the wide swath in range domain requires a low pulse repetition frequency (PRF) to avoid range ambiguity, but low PRF leads to undersampling, thus causing the azimuth ambiguity.This thesis focuses on the suppression of azimuth ambiguity, especially on the suppression method based on multiple channel and its impact on InSAR processing. The main content and innovation are as follows:1 This thesis analyzes three main problems in suppression method based on SIMO-SAR system:channel imbalance, the transmission path error, azimuth nonuniform sampling. Give expression of phase errors which caused by channel imbalance and azimuth nonuniform sampling problems to provide help for the subsequent InSAR processing.2 Provide an equivalent phase center model. To compensate the transmission path error, a compensation method based on BP algorithm is proposed. Simulation results show the effectiveness of the method, and pointed out that this method has higher compensation accuracy compared to the traditional transmission path error compensation method.3 The transmission path error caused by equivalent method when scene get height is analyzed. For improving the compensation accuracy of the transmission path, a height approximation based on iterative methods is proposed. The effectiveness of the method is verified by scene simulation. At last, the traditional approach based on CS algorithm and the highly compensate approach based on BP algorithm are compared.