Simulation And Study Of Airborne Ground Clutter In A Look Down Mode

Radar clutter is still a hot topic after decades of study. Pulse-Doppler radar clutter is quite strong with widely distributed power spectrum. Especially when the radar is in the"look down mode", it is the background of target detection in all range gates. So calculation and study of airborne radar clutter has become a basic and critical problem in the field of clutter research.After analyzing the surface clutter scattering mechanism of airborne radar, combining with the clutter characteristic of airborne radar in a look down mode, the characteristics of clutter signal including special correlation and time correlation, is summarized in the beginning. Then discussions are presented on several common algorthms for clutter simulation and simulation results are shown after that. Grid partition method is a common used method in analyzing and calculating ground clutter. In this paper, several ways of grid partition are summarized. Considering that some cells might exceed radar resolution because of their non-uniform sizes and various shapes, an idea that ground clutter of airborne radar can be treated as extended target is proposed. Because angular glint is the main characteristic of the extended target, so in this paper, amplitude fluctuation of ground clutter caused by this characteristic is simulated. In order to improve accuracy of the simulation, corresponding algorithm with special frequency-domain characteristic is proposed, and further simulation is made for comparison. Based on former discussions over characteristics of ground clutter and study on backscattering coefficient of airborne radar ground clutter, an algorithm, which is used to calculate power spectrum of ground clutter of airborne radar based on fluctuated RCS, is proposed. In this paper, all simulations are carried on Matlab platform and results accord well with theoretical analysis. So effectiveness of the algorithms is identified and simulation fidelity improved.