normal_l.m

进行ISAR运动补偿的程序 kylsdone 方法来消除越距离单元走动,注释完整

 function [s,V] = normal_l(z,rho,theta)
 % flinction NORMAL_L.M
 % Linear Interpolation Method
 % [s,V] = normal_1(z,rho,theta)
 % z= M by N matrix
 % rho, theta = radius and angles of data points
 % s = interpolated matrix
 % V vector that includes [XO dkx dky fi]

 close all

 % Variables
 bursts = size(z,1); pul_burst = size(z,2);
 thetav = theta(:,1).'; dtheta =thetav(2) - theta(1);
 tv=thetav;
 ac = max(thetav) - min(thetav);
 ca = (max(thetav) + min(thetav))/2;
 rho = rho.*(4*pi/3e8);   %% frequency matrix in rad/mt
 rhov = rho(1,:); X0 = pi/(rhov(2)-rhov(1));
 rhoc = linspace(min(rhov),max(rhov)*cos(ac/2),pul_burst);
 rhoy = linspace(min(rhov)*tan(min(tv)-ca),min(rhov)*tan(max(tv)-ca),bursts);
 drho = rhov(2) - rhov(1); dkx = drho; dky = abs(rhoy(2) - rhoy(1));
 s = zeros(size(rho)); s2 = s;

 %%% Linear interpolation in x direction 
 flops(0); zreal = zeros(bursts,pul_burst); zimag = zreal;
 for a = 1:bursts,
    projx = rhoc./cos(thetav(a) - ca);
    zreal(a,:) = interp1(rho(a,:)+1.5e-5,real(z(a,:)),projx,'linear');
    zimag(a,:) = interp1(rho(a,:)+1.5e-5,imag(z(a,:)),projx,'linear');
 end
 z = zreal + j * zimag;

 %%% Linear interpolation in y direction 
 zreal = zeros(bursts,pul_burst); zimag = zreal;
 for i = 1:pul_burst,
    projy = rhoc(1,i).*tan(thetav - ca);
    zreal(:,i) = interp1(projy,real(z(:,i)),rhoy,'linear')';
    zimag(:,i) = interp1(projy,imag(z(:,i)),rhoy,'linear')';
 end
 s = zreal +j.*zimag; fl = flops;
 V=[X0 dkx dky fl];