哈工大微波成像技术

for n=1:Ntarget for k=1:N_slow

R(1,k)=sqrt((Rb+P(n,2))^2+(t_slow(1,k)*V-P(n,1))^2); temp_win=find(abs(t_fast-2*(R(1,k)-Rmin)/c)

win_r1(temp_win)=hamming(length(temp_win))';%%%%对回波数据加窗 % win_r1(temp_win)=ones(size(temp_win));

sr(k,:)=sr(k,:)+exp(-j*4*pi*R(1,k)/lamda+j*pi*Kr*(t_fast-2*(R(1,k)-Rb)/c).^2).*...

win_r1.*(abs(t_slow(1,k)*V-P(n,1))<(Ls/2)); end end

% figure,imagesc(real(sr)); % title('回波数据支撑区')

% xlabel('距离向');ylabel('方位向'); t=(-Np/2:Np/2-1)*(1/Fr); win_r2=hamming(length(t))'; % win_r2=ones(size(t));

h=win_r2.*exp(j*pi*Kr*t.^2).*(abs(t)

srf(k,:)=fft(sr(k,:),N_fft); sof(k,:)=srf(k,:).*conj(hf);

so(k,:)=ifft(sof(k,:));%%%%距离向压缩后输出 end

figure;plot(db(so(160,:)/max(so(200,:)))); % imagesc(abs(so(:,1:Nwg))); % xlabel('距离向');ylabel('方位向'); % title('距离压缩后的回波数据');

figure; SSo=20*log10(abs(so)/max(max(abs(so)))); % mesh(SSo(200:300,1000:1200)); [tempM,tempN]=size(SSo);

mesh(SSo(200:250,tempN/7*3:tempN/7*4)); Nwa=floor(S*PRF); t=(-Nwa/2:Nwa/2-1)/PRF;

% win_a1= hamming(length(t))';%方位向窗函数 win_a1=ones(size(t));

win_a1=[zeros(1,round((N_slow-Nwa)/2)),win_a1,zeros(1,N_slow-round((N_slow-Nwa)/2)-Nwa)];

saf=zeros(N_slow,N_fft); for i=1:N_fast

saf(:,i)=fftshift(fft(so(:,i).*win_a1'));%加窗变换到多普勒距离域 end %% 方位压缩

fa=(-N_slow/2:N_slow/2-1)*PRF/N_slow; for i=1:N_fft

Ka=-2*V^2/lamda/(Rmin+(i-1)*gate); haf=exp(-j*pi*fa.^2/Ka); saf(:,i)=saf(:,i).*(haf'); saf(:,i)=ifft(saf(:,i)); end

% figure; Gr=abs(saf);

% imagesc([Rmin,Rmax],[-Ls,Ls],Gr(:,1:Nwg)); % axis([Rmin,Rmax,-Ls,Ls]);

% xlabel('距离/m');ylabel('方位/m'); % title('多散射点二维SAR条带式成像结果');

figure; Gr=20*log10(abs(saf)/max(max(abs(saf)))); mesh(Gr(200:280,950:1200));

xlabel('距离向');ylabel('方位向');zlabel('幅度/dB') title('单个散射点二维SAR条带式成像结果'); axis tight