Study On Calibration Experiment Of Airborne Interferomtric SAR

In this thesis the key problems of interferometric parameter calibration are systematically investigated in airborne interferometric SAR systems. Thoroughly studies on airborne interferometric SAR calibration are carried out, especially on the surveying geometric principles, the theoretical analysis, principles of high quality DEM reconstruction and processing of InSAR data, master the key technologies of how to improve the accuracy of generating the DEM by airborne InSAR system. On this basis, many key issues about calibration, such as calibration method and model et al, are provided through theoretical analysis and experimental study, many valuable discussions about calibration techniques have been done by this paper.Base on the mapping principle of airborne InSAR, introduce some coordinates that are commonly used in airborne InSAR photogrammetry mapping, and give some of the conversion relationships between the coordinates. In this paper, starting from the basic equation of SAR, take full advantage of the basic measurements, a new three-dimensional reconstruction analytic algorithm of the airborne interferometric SAR, is proposed on the models of spherical earth and spherical wave, the solution is demonstrated more exact than the existing algorithms, moreover, give the calibration models of plane and elevation.For the calibration models, the sensitivity equations can be derived by differentiating the target lacation equation with respect to different interferometer parameters. Through sensitivity analyses, the influence on the interferometric performance exerted by the parameter errors can be quantitatively evaluated. Therefore, the sensitivity equations are an important tool for interferometric SAR system optimization and calibration. This paper uses simulated datas to calibrate, according to the results of the calibration, analysis sensitivity of each interference parameters for the target location on the ground, and by interference phase, parameters under certain circumstances, corner reflectors can be reasonable layout in the calibration field to improve the calibration precision.To investigate the problem of Sensitivity calibration algorithm convergence and inherent defection of sensitivity model, introduce a new calibration method based on genetic algorithm. Parameter errors can be fixed in the high-dimensional error-space by the optimization calibration algorithm, the process keep to certain rules. In this paper, use the same simulation datas, use two calibration methods of sensitivity and genetic algorithm to calibration, and their results are compared.In this paper, calibration flight test industry was underway in the city of Changzhi in Shanxi Province, obtain test datas, ground control points using GPS measurements. Under the theory of calibration, an algorithm of locating calibrators is presented to achieve optimal results. In this paper, use sensitivity and genetic algorithm to calibration with the test datas, analyse the results of calibration.