Читать книгу Inverse Synthetic Aperture Radar Imaging With MATLAB Algorithms - Caner Ozdemir - Страница 80

%--------------------------------------------------------- % This code can be used to generate Figure 2.17 %--------------------------------------------------------- clear close all t=-25e-9:0.01e-9:25e-9; % choose time vector N=length(t); sine(2451:2551)=-sin(2*pi*1e9*(t(2451:2551))); % form sine pulse sine(N)=0; % Frequency domain equivalent dt=t(2)-t(1); % time resolution df=1/(N*dt); % frequency resolution f=0:df:df*(N-1); % set frequency vector sineF=fft(sine)/N; % frequency domain signal %---Figure 2.17(a)------------------------------------------------ plot(t(2251:2751)*1e9,sine (2251:2751),'k','LineWidth',2); grid minor set(gca,'FontName', 'Arial', 'FontSize',12,'FontWeight','Bold'); xlabel('\ittime, ns'); ylabel('\itamplitude, V'); axis([-2.5 2.5 -1.1 1.1]); %---Figure 2.17(b)------------------------------------------------ figure plot(f(1:750)/1e9,20*log10(abs(sineF (1:750))),'k','LineWidth',2); grid minor set(gca,'FontName', 'Arial', 'FontSize',12,'FontWeight','Bold'); axis([0 f(750)/1e9 -85 -20]); xlabel('\itfrequency, GHz'); ylabel('\itamplitude, dB');