《合成孔径雷达成像算法与实现》Figure2.16

 代码复现如下：

clc
close all
clear all

N = [4,8,16,8];
n = 256;
n1 = 2^10;
for i = 1:4
    %t = -N(i)/2:1/n:N(i)/2-1/n;
    t = linspace(-N(i)/2,N(i)/2,n);
    y = sinc(t);
    title_1 = [num2str(N(i)),'点sinc插值核'];
    if i == 4
        y = sinc(t).*kaiser(length(t),2.5)';
        title_1 = ['加Kaiser窗的',title_1];
    end
    dt = N(i)/n;
    fs = 1/dt;
    f = -fs/2:fs/n1:fs/2-fs/n1;
    Sf = fftshift(fft(y,n1));
    subplot(2,2,i),plot(f,abs(Sf)/max(abs(Sf)),'k')
    axis([-1,1,0,1.1]),xlabel('频率'),ylabel('幅度')
    title(title_1)
end