Study On The Airborne SAR Moving Target Detection And Parameter Estimation

This dissertation studies the key techniques of airborne SAR MTD, makes an improvement on it in order to get higher detection probability by estimating the parameters of moving targets and presents several novel parameter estimation approaches that are more efficient and useful in practice. The main work of this dissertation is as follows.1. Based on the principle of STI, this paper improves the estimation of the slow-moving target's parameters and its location in SAR system. It can estimate the radial velocity and central Doppler frequency of the slow-moving target and locate the target by using only two antennas under the circumstance of lower SCR.2. According to the influence of the clutter to GMTD in SAR system, this paper uses a method combining elimination of the clutter with refocus of the moving targets. Because the defocus signal from one moving target in figure is still approximately a LFM signal, by using the relationship between FrFT and time-frequency distribution, we can estimate its Doppler frequency rate and deduce the true one to refocus the target in figure. By doing this ,the performance of GMTD can be enhanced according to the higher SCR.