Applying Time-Frequency Analysis In Radar Signal Processing

Mainly this paper discusses applying time-frequency analysis in several questions, including estimation of Doppler parameter imaging of SAR , detection of moving target and estimation of direction of arrival in array signal processing.In estimation of Doppler parameter imaging of SAR, this paper analyses the theory of using Wigner-Ville Distribution and Hough transform to estimate Doppler parameter, and tests the availability of this method by emulation, and also gets good result in compare with time emulation. Then it also introduces the fractional Fourier transform. In contrast with WVD-HT, the fractional Fourier transform is more precise and more robust.In detection of moving target, we compare the detected performance of three methods. Although Gabor transform isn't affected by across-term, its time-frequency resolution is low. Wigner-Ville Distribution has highest time-frequency resolution for LFM signal; nevertheless it is affected by across-term badly and halves the interval of detectable velocity. The fractional Fourier transform is linear time-frequency transform, and it doesn't have disadvantages of Wigner-Ville Distribution. Moreover, the precision of this method is higher, and the performance of antinoise is better.In estimation of direction of arrival, this paper theoretically analyses advantages of the method based on spatial time-frequency distribution. It also gives two methods based on spatial time-frequency matrix to estimate the direction of arrival. It tests the performance of these methods in compare with MUSIC by emulation.