The Research Of Velocity Estimation And HRR Profile Stitching Algorithm Of Extended Moving Target For Stepped Frequency Radar

The synthetic high-range-resolution radar has drawn attentions due to its high-range-resolution, low system complexity, low cost and easy implementation. The work of this dissertation is focused on researches of stepped frequency radar including its velocity estimation and profile extraction problems. The main content of this dissertation is summarized as follows:Chapter 1 introduces the research background and the motivation of this dissertation and reviews the previous work including related research history and current status of velocity estimation and profile extraction. The arrangement of this dissertation is briefly introduced at last.Chapter 2 first introduces the waveforms and math expressions of the stepped frequency signal including its improving forms which can reduce bandwidth of the receiver and system complexity. Then, the imaging theories of the stepped frequency radar about both stationary point target and stationary extended target are deduced. Furthermore, the imaging theories in the condition of over-sampling are discussed. At last, some other signal processing methods for stepped frequency signal are introduced.The work of Chapter 3 is focused on the velocity estimation methods for moving targets. Firstly, effect of velocity on the high-range-resolution profile is discussed. Secondly, this chapter summarizes some velocity estimation methods and provokes a new velocity estimation method by using accurate frequency estimation and FFT. Furthermore, improves an already existing velocity estimation method. At last, two velocity abstraction methods are explored by aiming at the extended target.In Chapter 4, the profile extraction methods are analyzed. The system parameters and their effect on profile extraction methods are firstly discussed. By summarizing and contrasting some typical profile extraction methods, the effect of velocity on the extraction methods is revealed. In order to get rid of the effect, the traditional methods need to be improved. Then, two methods are discussed to revise the traditional methods.Chapter 5 mainly works on how to combine the velocity estimation methods and profile extraction methods together in order to get best high-range-resolution profiles. First of all, the signal processing flow and the main parts of the stepped frequency radar are analyzed. Then, two implementations are introduced to combine velocity estimation and profile extraction problems. Finally, the performance of the two implementations are discussed and contrasted.At last, a conclusion of this dissertation is made and some related problems to be solved and some works to be done are pointed out.