Research And Implementation Of Synthetic Aperture Radar Parallel Imaging Algorithm

Synthetic Aperture Radar (SAR) is a microwave imagining system, which has two-dimensional (range-dimensional and azimuth-dimensional) high resolution. SAR is widely used in globe remote sensing, sea research, source monitor, disaster prediction and military reconnaissance. With the development of SAR processing techniques, high image precision and high real-time rate have becoming more and more important, especially on military filed. High image precision means more complicated algorithm and more computing time, but the requirement for real-time rate limits the processing time, so the high performance processors have to be used for SAR imaging in order to obtain required real-time rate. There are two methods on real-time imaging, one is the special SAR processing system and another is the general-purpose parallel computer. The first method has the advantages of smaller volume, lighter weight, and can be used as air-borne or space-borne equipment, but it has the disadvantages of higher cost, longer developing time and worse adaptation. The second method hasn't these disadvantages and it can be easily upgraded. With the development of computing science, real-time processing with general-purpose parallel computer has become trend in radar-satellite ground processing system. Parallel processing is different from sequential processing. The efficiency of the same parallel algorithm on the different parallel computer will be completely different. To obtain high processing efficiency, the SAR parallel processing algorithm must be suitable to the parallel computer's hardware characteristics. This thesis is based on the subject of "Key Technology of Jianbing5 Ground Application System-High Efficiency SAR Imaging Project Research" After the deep research on SAR processing, two parallel imaging algorithms based on the existing sequential algorithms are presented in this thesis. These parallel algorithms are implemented on DAWNING parallel computer and get satisfactory result. The completion of this subject provides the foundation to solve the problem of SAR parallel imaging algorithm, parallel architecture, parallel operation system and parallel programming in our country's radar-satellite ground processing system. The main contents of this thesis can be concluded as following: I. Based on the discussion of SAR imaging theories and analysis of SAR echo signal model, some researches on simulation of point target andsurface target are made and simulating softwares are developed.Satisfactory results are got after imaging processing.2. Three popular imaging al gorithrn s -- Range/D opp l er(R/D ) al gorithIn,Secondary Range Compression(SRC) algorithIn and Chirp Scaling(CS)algorithm are discussed. am algorithIn was linPlemented in the RadarImaging Labtory of UESTC. We implement SRC and CS algoritlun insequence on this basis.3. Aiming at SAR parallel imaging actual aPplication, some briefintroduction and discussion on parallel comPuter architecfore, paral1elalgorithIn, parallel prograxnming and parallel pefformance estimation aregiven in this thesis.4. Medium grained parallel algorithIn and large grained parallel algoritlunfor SAR imaging based on SRC and CS algoritIun are presented. ThealgorithIn smicture and implementaion are analyzed and discussed.5. The software for SAR parallel imaging that can be executed on the PVM(Parallel VirtUal Machine) environment has been developed. The XSARraw data and the simulating LSAR data have been processed onDAWNING 2000 and DAWNING 3000.The SAR parallel imaging is an importan aspect fOr SAR research.The parallel imaging algorithms present...