Study On DBS Imaging And WAS-GMTI Method Of Airborne Radar

The Wide Area Surveillance Ground Moving Target Indication(WAS-GMTI)mode is an important work mode of the airborne battlefield surveillance radar.Under this mode,the radar can provide real-time surveillance over a wide area,and can even detect,localize and track moving targets in the ground scene by the radar antenna steered to different azimuth angle constantly.WAS-GMTI mode has the advantage of vast surveillance area,real-time reconnaissance and high revisit rate,hence it plays an important role in both military and civilian fields.Based on the signal processing procedure of the airborne radar WAS-GMTI mode,this paper focuses on studying the DBS imaging technology,ground moving target detection and localization techniques.A super-resolution wide-area imaging method based on Fast IAA algorithm and a moving targets localization method based on Fast IAA algorithm are proposed innovatively.Paper can be summarized as follows:1.The characteristic and principle of airborne radar WAS-GMTI mode are introduced,the azimuth detection zone and resolution ratio under the WAS-GMTI are analyzed,the signal processing methods and the signal processing flow in practical engineering are studied.2.The DBS imaging method is investigated.Since the conventional DBS method suffers from low resolution at azimuth,this paper proposed a super-resolution wide-area imaging method based on Fast IAA.In this method,the FFT procedure in the conventional method is replaced by the IAA algorithm,and fast algorithm is used for reducing the cost of computation.Simulation data experiment and real data processing show that the proposed method can effectively improve the resolution of the DBS image.3.The ground moving targets detection methods are studied in this paper.Aiming at the problem that the airborne radar usually faces the complex and changeful clutter environment,this paper studied the CFAR detection method which can adapt the change of the clutter’s dispersion pattern.By testing the dispersion pattern of the clutter and then choosing the corresponding CFAR detector,the detective performance can be improved effectively.For the phenomenon of many false alarms after CFAR,the target clustering method and the method of false alarms elimination are discussed.Finally summarize a complete and reasonable moving target detection processing flow,simulation results show the availability of the methods.4.The ground moving targets localization methods are discussed.By analyzing the phase comparison method and the main lobe of the interferometric phase search method,this paper proposed a new moving targets localization method based on the Fast IAA algorithm.By finding the peak position of the spectral estimation to confirm the location of the moving target,we can positioning the moving target accurately under the non-homogeneous clutter background.