Linear Array And Circular Sar Three-dimensional Imaging Algorithms

Three dimensional SAR system has the broad development prospects, because of its three dimensional imaging ability. At present, the linear array synthetic aperture radar (LASAR) system and the circular synthetic aperture radar (CSAR) are two kinds of most popular three dimensional imaging systems. According to the LASAR, its advantage is that it has the very high phase center control precision, and usually in the down-ward looking mode, which plays an important role in the terrain mapping area. According to the CSAR, its advantage is it has the high resolution of the along-track direction, and can get the information of the whole aspects. In this paper, we concerned on researching the imaging algorithm of LASAR and CSAR. The concrete details are:1. Introduced the basic theories of the LASAR and CSAR. Introduced the system models of two systems, deduced and analyzed the3d resolutions, and considered the measured data, researched the real3d imaging ability of CSAR, because of the varying of the RCS, the3d imaging ability of CSAR is very poor, then introduced the improvement mode of the CSAR——Multi-Pass CSAR, and deduced its3d resolution.2. Proposed the3d imaging algorithm based on rank-deficient robust capon beam-forming algorithm (Rank-Deficient RCB). For LASAR has weak resolution of the cross-track direction, proposed a3d imaging algorithm based on rank deficient RCB, this algorithm can break through the Rayleigh limitation, has the high resolution and high side-lobes reduced ability. The effectives of and advantages of this method is demonstrated through the simulation.3. CSAR experimental data processing and3d imaging algorithm researching. Used Ⅲpolar wave number region algorithm and the BP algorithm to process the measured data, compared imaging results, the wave number algorithm is a fast algorithm, but because of the dividing the data into section, the result is not well, BP algorithm is an elaborate algorithm, but its speed is slow. According to the results of two algorithms, we found that there are many high side-lobes in the3d imaging results, because of the sparse pass of the data set.4. Proposed a BP+CS imaging algorithm. In view of the actual situation in a limited number of passes in height to the problem of bad effect imaging, a BP+CS algorithm is proposed to improve the imaging results, compare the results of the proposed algorithm with the traditional BP algorithm’s, we proved the excellent performance of the proposed algorithm.