range_compress.zip_SAR 调频_range_range_compress

clear all; %%% parameters' definition c=3e+8; % speed of light pi=3.1415926; j=sqrt(-1); Tp=1.e-6; % transmitted pulse width fc=1.e+9; % carrier frequency Br=50.e+6; % transmitted bandwidth Fs=200.e+6; % A/D sample rate kr=Br/Tp; % range chirp rate Nr=Tp*Fs; Ni=1:Nr; tr=(Ni-Nr/2)*Tp/Nr; lamda=c/fc; %=============================== %Chirp pulse echo from point A %=============================== sig_point0 = exp(j*pi*kr*(tr).^2); %=============================== %Chirp pulse echo from point B %=============================== dr=3.5; dr_t=2*dr/c; dN=dr_t*Fs; %sig_point1 = exp(j*pi*kr*(tr-dr_t).^2); sig_point1 = exp(j*pi*kr*(tr-0*dr_t).^2+j*2*pi*2*dr/lamda); Nx=fix(3*Nr); sig_0 = zeros(1, Nx); sig_1 = zeros(1, Nx); sig_0(Nr+1:2*Nr)=sig_point0; sig_1(Nr+dN+1:2*Nr+dN)=sig_point1; %=============================== % Summary echo signal of A and B %=============================== sum_sig = sig_0 + sig_1; figure; subplot(4,1,1); plot(real(sig_0)); subplot(4,1,2); plot(real(sig_1)); subplot(4,1,3); plot(real(sum_sig)); %===================================== % Range compression with match filter %===================================== mf_sig = conj(fliplr(sig_point0)); mf_out = conv(sum_sig, mf_sig); Ns=Nr/2+1; Ne=3*Nr+Nr/2; subplot(4,1,4); plot(abs(mf_out(Ns:Ne)));