Chirp Sub-pulse Stepped Frequency Signal At Low Altitude Moving Target Detection Technology

Detecting target at low-altitude is one of important problems for radar. Based on high distance resolution is an important method of resolving this problem. Chirp-subpulse stepped frequency signal is one of the high distance resolution signals with merits of stepped-frequency signal and chirp signal. This dissertation analyses the characteristics of chirp-subpulse stepped frequency signal, and analyses and resolves kinds of problems in chirp-subpulse stepped frequency signal. This dissertation studies the use of chirp-subpulse stepped frequency signal in low altitude moving target, and studies and provides theoretical basis for practical application of chirp-subpulse stepped frequency signal and processing techniques.First, this dissertation analyses the waveform of chirp-subpulse stepped frequency signal, studies and simulates the ambiguity characteristics, the spectrum structure and the basic process to obtain high resolution range profiles, and discuss this signal's high range resolution characteristic and wide spectrum characteristic.Secondly, based on the analysis and simulations of the Doppler time-shift for chirp-subpulse stepped frequency signal, this dissertation analyses the velocity compensation method for moving targets in chirp-subpulse stepped frequency signal, and presents a method for compensation of targets'velocity base on the least burst error rule. This dissertation analyses problems of profile aliasing and redundance in chirp-subpulse stepped frequency signal, points out that these problems are resulted from different parameters of chirp-subpulse stepped frequency signal. This dissertation summarizes the method to select parameters of chirp-subpulse stepped frequency signal, presents a method to resolve profile aliasing and redundance in chirp-subpulse stepped frequency signal by the target pick-up algorithm and selecting parameters.Thirdly, this dissertation analyses the echo simulation of chirp-subpulse stepped frequency signal and chirp signal. And the detection capability of chirp-subpulse stepped frequency signal and chirp signal in low altitude moving target is compared. The results show that chirp- subpulse stepped frequency is better. Hereby, this dissertation present system project with chirp-subpulse stepped frequency signal in...