readdata2.m

一些sar数据

clear all
tp=4.00025602e-5;   %脉冲宽度
fc=9.600000000000000e+009;  %中心频率
c=3e8; 
prf=1395.0;   %重复频率
lmda=c/fc;    %波长
gama=-2.3724394e+11;  %调频率
B=gama*tp;  %带宽
fs=1.12492800e+7;  %采样率

% 对此数据进行距离匹配滤波－方位匹配滤波成像

fd1=fopen('raws.dat','rb');
s=fread(fd1,'uchar');
fclose(fd1)
s=s(1:2:2097152)+j*s(2:2:2097152);
s=reshape(s,1024,1024);
s=s-mean(mean(s));
[ran_num,azi_num]=size(s);
% 列为距离快时间  行为方位慢时间
nan=azi_num;
nrn=1024;

tp_nan=200;
tp_nrn=fix(tp*fs);
x=zeros(nrn+tp_nrn,nan+tp_nan);
x(tp_nrn/2+1:nrn+tp_nrn/2,tp_nan/2+1:nan+tp_nan/2)=s;
s=x;
clear x;
[nrn,nan]=size(s);

 
t=[-tp_nrn/2:tp_nrn/2-1]'/fs; %距离快时间匹配 
serf_r1=exp(-j*pi*gama*t.^2);%距离匹配函数
serf_r=[zeros((nrn-tp_nrn)/2,1);serf_r1;zeros((nrn-tp_nrn)/2,1)];
for n=1:nan                              
    s(:,n)=ifftshift(ifft(fft(fftshift(s(:,n))).*conj(fft(fftshift(serf_r)))));
end



ka=9357;                      %方位慢时间匹配
t=[-tp_nan/2:tp_nan/2-1]/prf;
serf_a1=exp(-j*pi*ka*t.^2);%方位匹配函数
serf_a=zeros(1,nan);
serf_a(1,nan/2-100:nan/2+100-1)=serf_a1;
for n=1:nrn                         
   s(n,:)=ifftshift(ifft(fft(fftshift(s(n,:))).*conj(fft(fftshift(serf_a)))));
end