The Study Of Airborne Multi-channel SAR/GMTI Algorithm And Its Hardware Implementation

In the recent years, ground moving target detection and imaging has become a hot topic in the field of Synthetic Aperture Radar (SAR), and has been highly valuable for both military and civilian application. This dissertation mainly studies multi-channel SAR/GMTI techniques, and the GMTI processing of the measured data is implemented on general digital signal processing system.The main work of this dissertation is as follows:In chapter 1, firstly, we review the research background and current situation of SAR/GMTI technique. Secondly, the applications of DSP technology in radar signal processing is introduced briefly. Finally, the main contents of the dissertation are addressed.In chapter 2, the SAR image-error-spectrum model of the moving target is firstly defined.Then, the image-error-spectrum after the PFA processing is derived. On the basis of the image-error-spectr- um, detailed analysis on the SAR signatures of moving target, including the geometric displacement, residual range migration, and the defocusing effect in both range and azimuth dimensions is performed. Finally, the simulation results validate the theoretical analysis.In chapter 3, an effective dual-channel SAR/GMTI method based on eigen-decomposition of sample covariance matrix is investigated in detail. Numerical experiments on simulated data and measured data are presented to show that the second eigenvalue after eigen-decomposition of the sample covariance matrix can be applied to detect moving targets effectively. Subsequently, the radial velocity and relocation of the detected target are estimated by superresolution method. At the same time, we analyze the factors that affect the accuracy of the estimated velocity and relocation, including the signal noise ratio and the number of samples in the covariance estimation.In chapter 4, firstly, theΣ/Δbeam interferometric SAR/GMTI technique is theoretically analyzed. Then, the performance analysis of theΣ/Δbeam interferometric SAR/GMTI is presented. Finally, the measured data processing confirms that the slow-moving targets masked in clutter can be detected via this technique, while the radial velocity and relocation of the detected target are estimated.In chapter 5, it is studied that the implementation of aforementioned SAR/GMTI algorithms on general digital signal processing system. In the light of the detectable algorithm and the hardware recourse of the system, after the parallel division of the processing tasks in chapter 3 and 4, the parallel processing of the ground slow-moving target detection algorithm is realized on general digital signal processing system, and the resulting detection of the measured data is given.In chapter 6, the work of this dissertation is concluded and the further research is also pointed out.