雷达目标检测之恒虚警检测(CA/SOCA/OS/GOCA-CFAR)【附MATLAB代码】

作品简介

MATLAB主代码:

clear; close all; clc;
% 生成一个例子,然后用以下算法处理
% CA CFAR, OS CFAR, SOCA CFAR, GOCA CFAR, S-CFAR, Log CFAR
% 位置在50和55处有目标,50处信噪比10dB,55处信噪比15dB
% 前100单元噪声功率20dB,后100单元噪声功率30dB
​
num_cell = 200;
Pfa = 10^(-5);
​
signal1 = generateDataGaussianWhite(100, [50, 55], [35, 40], 20);
signal2 = generateDataGaussianWhite(100, [], [], 30);
signal = [signal1, signal2];
plot(1:num_cell, pow2db(signal), 'k-', 'linewidth', 0.5);
hold on;
​
% CA CFAR处理
[position, threshold, start_cell, stop_cell] = cacfar(signal, Pfa, 10, 2);
plot(start_cell:stop_cell, pow2db(threshold), 'linewidth', 1);
% OS CFAR处理
[position, threshold, start_cell, stop_cell] = oscfar(signal, Pfa, 10, 2, 15);
plot(start_cell:stop_cell, pow2db(threshold), 'linewidth', 1);
% SOCA CFAR处理
[position, threshold, start_cell, stop_cell] = socacfar(signal, Pfa, 10, 2);
plot(start_cell:stop_cell, pow2db(threshold), 'linewidth', 1);
% GOCA CFAR处理
[position, threshold, start_cell, stop_cell] = gocacfar(signal, Pfa, 10, 2);
plot(start_cell:stop_cell, pow2db(threshold), 'linewidth', 1);
​
​
grid on;
legend('信号', 'CA CFAR阈值', 'OS CFAR阈值', 'SOCA CFAR阈值', 'GOCA CFAR阈值');

CA-CFAR

function [position, threshold, start_cell, stop_cell] = cacfar(signal, Pfa, ref_num, guard_num)
    % ======>INPUT:
    % signal: Data of signal(include signal and noise).[DATATYPE: row vector]
    % Pfa: Probability of false alarm.[DATATYPE: scalar]
    % ref_num: Number of reference cell.[DATATYPE: scalar]
    % guard_num: Number of guard cell.[DATATYPE: scalar]
    % ======>OUTPUT:
    % position: positions of target.[DATATYPE: row vector]
    % threshold: CFAR threshold of input signal.[DATATYPE: row vector]
    position = [];
    left_num = guard_num + ref_num;
    start_cell = left_num + 1;
    stop_cell = length(signal) - left_num;
    N = 2*ref_num;
    alpha = N * (Pfa ^ (-1/N) - 1);
​
    threshold = zeros(1, stop_cell - start_cell + 1);
    for ii = start_cell : stop_cell
        tmp_data = [signal(ii-left_num : ii-guard_num-1), ...
                    signal(ii+guard_num+1 : ii+left_num)];
        tmp = mean(tmp_data) * alpha;
        % threshold(ii - left_num)
        % tmp
        threshold(ii - left_num) = tmp;
        if tmp < signal(ii)
            position = [position, ii];
        end
    end
return


MATLAB仿真结果:

SOCA/OS/GOCA-CFAR代码:

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