Читать книгу Inverse Synthetic Aperture Radar Imaging With MATLAB Algorithms - Caner Ozdemir - Страница 76

%--------------------------------------------------------- % This code can be used to generate Figure 2.9 %--------------------------------------------------------- %---Figure 2.9a--------------------------------------------- clear close all fo=1e3; % set the frequency t=-4e-3:1e-7:4e-3; % choose time vector s=cos(2*pi*fo*t); % time domain CW signal plot(t*1e3,s,'k','LineWidth',2); grid minor set(gca,'FontName', 'Arial', 'FontSize',12,'FontWeight','Bold'); xlabel('\ittime, ms'); ylabel('\itamplitude, V'); axis([-4 4 -1.2 1.2]) %---Figure 2.9(b)------------------------------------------- N=length(t); df=1/(t(N)-t(1)); % Find frequency resolution f=-df*(N-1)/2:df:df*(N-1)/2; % set frequency vector figure; S=fft(s)/N; % frequency domain CW signal plot(f*1e-3,fftshift(abs(S)),'k','LineWidth',2); grid minor set(gca,'FontName', 'Arial', 'FontSize',12,'FontWeight','Bold'); xlabel('\itfrequency, KHz'); ylabel('\itamplitude, V'); axis([-.8e1 .8e1 0 .6])