The Study Of Ground Moving Target Indication With Synthetic Aperture Radar

Ground Moving Target Indication (GMTI) is a hot topic in the area of SyntheticAperture Radar (SAR) and plays an important role in both martial field and civilianfield. This dissertation focuses on the SAR GMTI algorithms, includingsingle-channel and multi-channel system. The major devotement of this dissertation isas follows.Firstly, the dissertation analyzes the basic theory regarding SAR GMTI. Athree-dimensional curve model for moving target echoes is set up. Then the propertiesof ground clutter and system noise are examined from the point of view of statistics,and the power spectral densities of which are derived for pulsed doppler radar.Secondly, based on the SAR/GMTI project research, the consecutive sub-aperturealgorithm is designed for single-channel SAR system. The dissertation mainlydiscusses how to design radar system parameters according to the given performancemetrics, and corresponding simulations are presented. The algorithm is evaluated byreal data and moving vehicles can be detected under proper thresholds.Thirdly, with regard to multi-channel GMTI system, several key issues of ATItechnology are discussed. A new algorithm of data co-registration is proposed,through which the data from different channels can be co-registered precisely viaphase compensation idea in range-Doppler domain, where the interpolation operationisn't required. The statistics of the phase of interferometric signal is also examined,and the coherence coefficient is analyzed in detail. The intrinsic problems such asblind velocity and solution ambiguities in dual-channel system are discussed, andmulti-channel system is investigated in order to partly solve these problems andimprove the solution accuracy.Finally, Detecting moving targets in Range-Doppler domain for multi-channel system is investigated and improved. A new algorithm based on Chirp-Z transform forGMTI in range-Doppler domain is proposed. The received data from differentchannels can be co-registered precisely along azimuth direction after beingtransformed into Doppler domain via CZT, and moving target can be detected throughinterferometry procedure combined with spectrum phase compensation. Thealgorithm is verified by simulation.