| At present, we still based on the normalization of pluse radar echo cross-sectional area of the statistical for research on the characteristics of radar sea clutter. Radar sea clutter is satisfy a certain probability density function of related sequences, this is reflected in its amplitude distribution and spectrum property. And not only the study of linear frequency modulation continuous wave radar clutter are rare, but also the related literature and the measured data. In this paper, according to the signal processing theory of linear frequency modulated continuous wave radar and the classical statistical models of pulse radar sea clutter, deduced the calculation formula of linear frequency modulation continous wave radar sea clutter, then simulate the sea clutter of linear frequency modulation continous wave radar under typical sea state, analyses its amplitude probability density function distribution and spectrum property. And simulate echo singal which includes sea clutter, noise and point target, use the “Beat-FFT†singal processing system by linear frequency modulation continous wave radar, it successfully extract the preset target which includes distance and velocity information. The main work of this paper as follows:1. Analyze the echo of moving target respectively at zigzag and symmetrical triangular linear frequency modulation continous wave radar in single and multiple sweep frequency cycle. According to the “Beat-FFT†signal processing system,introduce the characteristic of beat singal and its fourier transform singal after mixer.Analyze the classical clutter statistical model on pulse radar, use the widely recognized clutter modeling method to simulate out several kinds of typicalmodel of sea clutter, the simulation result has matched theoretical value well.2. According to the characteristics between linear frequency modulation continous wave radar and pulse radar, establish the relationship between transmit signal at each sweep frequency cycle and each pulse. According to the range resolution of linear frequency modulation continous wave radar, divide the radar illumination to several distance cell on radial distances. Thus deduce the sea clutter calculation formula of linear frequency modulation continous wave radar.3. According to the calculation formula, analysis of the distance correlation,amplitude distribution and correlation property, and validate the correctness of analysisresults with simulation data. at the same time, simulate out the echo model of zigzag and symmetrical triangular linear frequency modulation continous wave radar, which include sea clutter, noise and point target.4. Analyze correlation of distance, the characteristics of amplitude distribution and the characteristics of relevant of the beatsignal after mixer. |
