步进频率信号散射矩阵提取的MATLAB源代码

% SFW信号 FFT 两个点目标 散射矩阵提取 Zhao[D] edit by lzf on 2013.01.07 % function [error_S1_abs,error_S2_abs]=SFW(SNR) %clear; c=3e8; fs=80e6; %采样率 freq_0=93e9; %起始频点 delt_freq=5e6; %步进频率 freq_N=512; %频率步进点数 PRI=50e-6; %脉冲重复周期 % duty_circle=0.1; pulse_wide=2e-6; %脉宽 t_fs=1/fs; %采样周期 pulse_n=freq_N; SNR=30; t_pulse=t_fs:t_fs:PRI; S1=[1,-1i;-1i,1]; R1=595; v0_1=0; S2=[1,0;0,-1]; R2=603; v0_2=0; t_return_1=(2*R1/c)*ones(1,PRI*fs); pulse_return_1=[zeros(1,round((2*R1/c)*fs)),ones(1,pulse_wide*fs),zeros(1,((PRI-pulse_wide)*fs)-round((2*R1/c)*fs))]; t_return_2=(2*R2/c)*ones(1,PRI*fs); pulse_return_2=[zeros(1,round((2*R2/c)*fs)),ones(1,pulse_wide*fs),zeros(1,((PRI-pulse_wide)*fs)-round((2*R2/c)*fs))]; E_HH_separate=zeros(pulse_n,PRI*fs); E_HV_separate=zeros(pulse_n,PRI*fs); E_VH_separate=zeros(pulse_n,PRI*fs); E_VV_separate=zeros(pulse_n,PRI*fs); for i2=1:pulse_n E_H_separate_1 = S1*[exp(1i*2*pi*(freq_0+(i2-1)*delt_freq)*(t_pulse+(i2-1)*PRI-t_return_1-2*v0_1*(t_pulse+(i2-1)*PRI)/c)).*pulse_return_1;zeros(1,PRI*fs)]; E_V_separate_1 = S1*[zeros(1,PRI*fs);exp(1i*2*pi*(freq_0+(i2-1)*delt_freq)*(t_pulse+(i2-1)*PRI-t_return_1-2*v0_1*(t_pulse+(i2-1)*PRI)/c)).*pulse_return_1]; E_H_separate_2 = S2*[exp(1i*2*pi*(freq_0+(i2-1)*delt_freq)*(t_pulse+(i2-1)*PRI-t_return_2-2*v0_2*(t_pulse+(i2-1)*PRI)/c)).*pulse_return_2;zeros(1,PRI*fs)]; E_V_separate_2 = S2*[zeros(1,PRI*fs);exp(1i*2*pi*(freq_0+(i2-1)*delt_freq)*(t_pulse+(i2-1)*PRI-t_return_2-2*v0_2*(t_pulse+(i2-1)*PRI)/c)).*pulse_return_2]; % E_H_separate=awgn(E_H_separate,m); % E_V_separate=awgn(E_V_separate,m); E_H_separate = E_H_separate_1 + E_H_separate_2; E_V_separate = E_V_separate_1 + E_V_separate_2; % E_HH_separate(:,j2)=real(E_H_separate(1,:)); % E_HV_separate(:,j2)=real(E_H_separate(2,:)); % E_VH_separate(:,j2)=real(E_V_separate(1,:)); % E_VV_separate(:,j2)=real(E_V_separate(2,:)); % E_HH_separate_o(i2,:) = E_H_separate(1,:); E_HH_separate(i2,:) = awgn(E_H_separate(1,:),SNR,4); E_VH_separate(i2,:) = awgn(E_H_separate(2,:),SNR,4); E_HV_separate(i2,:) = awgn(E_V_separate(1,:),SNR,4); E_VV_separate(i2,:) = awgn(E_V_separate(2,:),SNR,4); end % figure(3); % plot(t_pulse,real(E_HH_separate(1,:))); % N_2_sampling = abs(real(E_HH_separate(1,:))); % S_2 = mean(N_2_sampling(1,round((2*R2/c)*fs):round((2*R2/c)*fs)+pulse_wide*fs)); % N_2 = mean(N_2_sampling(end-1000:end)); % S2N_0 = 20*log10((S_2 - N_2)/N_2) % figure(1); % plot(t_pulse,E_HH_separate(:,1)); % % figure(2); % plot(t_pulse,E_HV_separate(:,1)); % % % figure(4); % plot(t_pulse,E_VV_separate(:,1)); %doppler_offset for i3=1:pulse_n down_wave=exp(-1i*2*pi*(freq_0+(i3-1)*delt_freq)*(t_pulse+(i3-1)*PRI)); E_HH_separate(i3,:)=E_HH_separate(i3,:).*down_wave; E_VH_separate(i3,:)=E_VH_separate(i3,:).*down_wave; E_HV_separate(i3,:)=E_HV_separate(i3,:).*down_wave; E_VV_separate(i3,:)=E_VV_separate(i3,:).*down_wave; end n0=round((2*R1/c)*fs + pulse_wide*fs/2); E_HH_separate_angle = angle(E_HH_separate(:,n0)); E_HH_separate_abs = abs(E_HH_separate(:,n0)); E_HH_separate_fft = fft(E_HH_separate); E_VH_separate_fft = fft(E_VH_separate); E_HV_separate_fft = fft(E_HV_separate); E_VV_separate_fft = fft(E_VV_separate); for i3=1:PRI*fs E_HH_separate_fft(:,i3) = fftshift(E_HH_separate_fft(:,i3)); E_VH_separate_fft(:,i3) = fftshift(E_VH_separate_fft(:,i3)); E_HV_separate_fft(:,i3) = fftshift(E_HV_separate_fft(:,i3)); E_VV_separate_fft(:,i3) = fftshift(E_VV_separate_fft(:,i3)); end % % figure(1); % mesh(1:PRI*fs,(-freq_N/2:freq_N/2-1)*c/(2*freq_N*delt_freq),abs(E_HH_separate_fft)); % figure(2); % mesh(1:PRI*fs,(-freq_N/2:freq_N/2-1)*c/(2*freq_N*delt_freq),abs(E_VH_separate_fft)); % figure(3); % mesh(1:PRI*fs,(-freq_N/2:freq_N/2-1)*c/(2*freq_N*delt_freq),abs(E_HV_separate_fft)); % figure(4); % mesh(1:PRI*fs,(-freq_N/2:freq_N/2-1)*c/(2*freq_N*delt_freq),abs(E_VV_separate_fft)); E_HH_separate_fft_sampling = fliplr(conj(E_HH_separate_fft(:,n0)')); E_VH_separate_fft_sampling = fliplr(conj(E_VH_separate_fft(:,n0)')); E_HV_separate_fft_sampling = fliplr(conj(E_HV_separate_fft(:,n0)')); E_VV_separate_fft_sampling = fliplr(conj(E_VV_separate_fft(:,n0)')); S_Measure_1 = zeros(1,4); S_Measure_2 = zeros(1,4); % figure(1); subplot(2,2,1); plot((-freq_N/2+1:freq_N/2)*c/(2*freq_N*delt_freq),abs(E_HH_separate_fft_sampling),'k');title('HH极化HRRP'); figure(1); subplot(2,2,2); plot((-freq_N/2+1:freq_N/2)*c/(2*freq_N*delt_freq),abs(E_VH_separate_fft_sampling),'k');title('VH极化HRRP'); figure(1); subplot(2,2,3); plot((-freq_N/2+1:freq_N/2)*c/(2*freq_N*delt_freq),abs(E_HV_separate_fft_sampling),'k');title('HV极化HRRP'); figure(1); subplot(2,2,4); plot((-freq_N/2+1:freq_N/2)*c/(2*freq_N*delt_freq),abs(E_VV_separate_fft_sampling),'k');title('VV极化HRRP'); max_point = find_max_point_new(E_HH_separate_fft_sampling,2); % %N_3_sampling = abs(E_HV_separate_fft_sampling); %N_3 = mean(N_3_sampling(end-40:end)); %S2N = 20*log10((max(N_3_sampling)-N_3)/N_3) if max_point(1)>max_point(2) xx = max_point(1); max_point(1) = max_point(2); max_point(2) = xx; end S_Measure_1(1) = 1; S_Measure_1(2) = E_VH_separate_fft_sampling(max_point(1))/E_HH_separate_fft_sampling(max_point(1)); S_Measure_1(3) = E_HV_separate_fft_sampling(max_point(1))/E_HH_separate_fft_sampling(max_point(1)); S_Measure_1(4) = E_VV_separate_fft_sampling(max_point(1))/E_HH_separate_fft_sampling(max_point(1)); S_Measure_2(1) = 1; S_Measure_2(2) = E_VH_separate_fft_sampling(max_point(2))/E_HH_separate_fft_sampling(max_point(2)); S_Measure_2(3) = E_HV_separate_fft_sampling(max_point(2))/E_HH_separate_fft_sampling(max_point(2)); S_Measure_2(4) = E_VV_separate_fft_sampling(max_point(2))/E_HH_separate_fft_sampling(max_point(2)); S_vector_1=[S1(1,:),S1(2,:)]; S_vector_2=[S2(1,:),S2(2,:)]; % S_error_1 = S_Measure_1 - S_vector_1; S_error_1 = abs(S_Measure_1) - abs(S_vector_1); error_S1 = sqrt(abs(S_error_1(2))^2+abs(S_error_1(3))^2+abs(S_error_1(4))^2); error_S1_abs = abs(error_S1); % S_error_2 = S_Measure_2 - S_vector_2; S_error_2 = abs(S_Measure_2) - abs(S_vector_2); error_S2 = sqrt(abs(S_error_2(2))^2+abs(S_error_2(3))^2+abs(S_error_2(4))^2); error_S2_abs = abs(error_S2);