Space Targets Broadband Imaging Technology To Study

The radar of wide-band and linear frequency modulation is this thesis's background. In the thesis the researching objects are motion targets with high speed or with spinning. The influence of high velocity has been analyzed and then the relative ways of compensation are introduced. From theory the influence of spinning motion which bring to the targets' one-dimension range-profile has been analyzed. The arithmetic of estimation of Signal with polynomial Phase is introduced and then spin compensation is realized.In chapter I ,the background of the article is introduced. The theory and method of space target recognition and space ISAR imaging is introduced too.At last, the main works of the article is introduced simply.In chapter II, the theory of ISAR imaging is introduced firstly. The mathermatic model of target's one-dimension range-profile is deduced. The space target's motion characteristic is researched and the characteristic of space targer's ISAR imaging is analyzed.In chapter III, for target with high speed the influence which bring to one-dimension range-profile and compensation method are analyzed . The radial motion will not only bring the range ambulation and windage to the one-dimension range-profile , but also bring the aberrance and blur produced on given condition that radar signal which is with large product of wide-time and wide-band. The reason producing aberrance and blur is analyzed in this chapter .The method of motion compensation is brought forward and the simulation is given.In chapter IV,the characteristic of spin target's one-dimension range-profile and the influence which bring to ISAR imaging is reached. Then corresponding compensation method is brought forward. The targets' time serial is provided by radar's narrow-band signal. From analyzing the characteristic of RCS time serial, we can judge the targets' gesture by adopting run-test algorithm which is from nonparametric statistic theory. The targets' time serial is provided by radar's narrow-band signal. From analyzing the characteristic of RCS time serial, we can judge the targets' gesture by adopting run-test algorithm which is from nonparametric statistic theory. The spinning motion makes the scattering dots changed rapidly during the imaging, which makes the one-dimension range-profile between conterminous targets change acutely. Through analyzing the spinning echo, the arithmetic of "estimation of Signal with polynomial Phase" is adopted to estimate parameter of echo's phase. Then the influence of high step phase produced by spin is removed. The one-dimension range-profile can be renewed by this arithmetic and the good effect is showed by the result of simulationIn chapter V, the main works of this dissertation are summarized and the future researched areas are pointed out.