Research On Constant False Alarm Processing Technology Based On Clutter Map

Radars at working will inevitably be affected by various types of clutter,such as ground clutter,sea clutter,weather clutter and chaff clutter.In radar signal processing,target detection in clutter environments is a very important part,when using the traditional mean value-like constant false alarm detector to detect,cannot achieve good detection effect.In order to improve the performance of target detection,clutter image processing technology is usually added to clutter background detection.This paper focuses on clutter graph CFAR detection technology,the main work is as follows:1.The basic principle of radar target detection is introduced,including signal detection in noise and signal detection in clutter.Four kinds of statistical models commonly used in radar clutter are described and analyzed,which are Rayleigh distribution,lognormal distribution,Weibull distribution and K distribution.The Rayleigh distribution clutter is simulated based on the zero memory nonlinearity(ZMNL)method for the simulation requirements of this paper.2.The principle of three mean class constant false alarm detectors is described,including CA-CFAR,SO-CFAR and GO-CFAR constant false alarm detector.The performance of each detector is analyzed,and the detection performance of aforementioned three detectors is compared and simulated with Matlab in the Rayleigh clutter background.The advantages and disadvantages of different mean class CFAR processing techniques and their applicability in different detection environments are obtained.3.This paper focuses on the classical Nitzberg clutter graph technology,analyzes the influence of attenuation factor and heterozygosity ratio detection performance.In the background of Rayleigh clutter,the detection performance of Nitzberg clutter graph technique is simulated with Matlab.It is concluded that the classical clutter graph CFAR detection algorithm is not affected by the edge of clutter and multi targets because of its time domain iterative characteristics,and the detection performance of high signal to clutter ratio is better.4.Based on the classical Nitzberg clutter graph technique,a binary clutter detection algorithm is proposed.The presented algorithm combines the binary detector with the clutter graph point technology,sets the high and low threshold for false alarm and leakage alarm which may result from the binary detector,and outputs the N scan pulse as a group of target detection results.Based on the theoretical basis of binary detector and Nitzberg clutter graph,the detection probability and false alarm probability of this algorithm are deduced,and the algorithm has constant false alarm characteristic.The detection performance of the algorithm is simulated under the Rayleigh clutter background,and it is concluded that the binary clutter detection cannot be affected by the edge of clutter and multiple targets,it further changes the continuous leak alarm that may be caused by the clutter point technique in the detection of low signal to heterozygous targets.