| With the development of radar technology, one of the obvious features of radar is the improved resolution. The imaging radar is a type of high-resolution radar, which is based on the technology of broadband microwave and advanced signal processing. By use of the imaging radar, which has broad applications and has become the focus of the field, the target can be imaged hi all weathers and at anytime from far distance.The object of IASR imaging is the moving target in space. The traditional RDA algorithm is based on the model of micro-motion scatters, but it is not fit for the real target at all. We must adopt some methods to correct the error, which is caused by the model mistermination, and the discussion is mentioned in the paper firstly.For some low-resolution radar on active duty, we can only get the Doppler cross image of the echo because of their low longitudinal resolution. Therefore some analysis and algorithms for low-resolution radar are given and verified by measured data and simulation data results.The interference technology is one of the focuses of radar imaging increasingly. Not only does it provide some additional information of target recognition and detection, but also has it other applications to three-dimension imaging, scaling and moving target detection and so on. And the baseline is one of the keys of the interferometer system. Some applications of interferometer technology are discussed.The summarization of the main work is as follows:+A method that can correct the migration through range cells caused by radial speed is presented by using scale transformation, and the method is extended to maneuvering target imaging. The algorithm flow, which is applicable to large-scale target whether it is uniform or maneuvering, is given. The results obtained by using simulation data and real data show that this method is effective. The method can hold not only for ISAR of flying target, but also for ground moving object and sea ship after adaptive clutter suppression.+The analysis of the algorithm of low-resolution radar is made. After the compensation based on the rule of the minimum entropy, the resolution of thecross-range image is lower as the large size and non-uniform rotation, which cause the image to be not right at all sometimes. In order to eliminate effect of the non-stationary rotation, the first order approximation and RELAX algorithm are adopted to search the initial frequency, amplitude, frequency modulation rate and obtain the dynamic image of the target at any time. Simulation results obtained using data and real data show that this method is effective.^For the active low-resolution radar, its longitudinal resolution usually is more than one hundred meters and as high as several hundred meters. Due to the short distance among the planes which fly in a group, the conventional low resolution radar can not distinguish them in both distance and azimuth ?If we use the technology of ISAR to resolve the difference among Doppler frequency of the targets and obtain a fine resolution cross-cross image, we may separate them, but a long time of coherent processing is needed <, For the formation targets, it can be approximately divided to rigid body and nonrigid body, so for the formation targets, that can be regarded as rigid which has a relative position and an identical movement, can be approximately considered as a large target, and be compensated by translational phase with the rule of minimum entropy , but for the most those cannot accord with the approximation of rigid, being the Doppler-frequency of the aim is linear changed, by the RELAX method with short data, increases the resolving performance of multiple target to the aim in the frequency domain, since cross-range resolution is based on the accumulative time, so it is greatly improve the resolution to formation targets by the instant cross-range image which produced by Radon-Wigner transformation.+As the scale of cross range image is dependent on the coherent accumulation and the rotation angle, we must s...
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