www.pudn.com > programradarsystemdisign.zip > fig1_16.m

% Use this program to reproduce Fig. 1.16 of text. 
close all 
clear all 
tsc = 2.5; % Scan time i s2.5 seconds 
sigma = 0.1; % radar cross section in m sqaured 
te = 900.0; % effective noise temperature in Kelvins 
snr = 15; % desired SNR in dB 
nf = 6.0; %noise figure in dB 
loss = 7.0; % radar losses in dB 
az_angle = 2; % search volume azimuth extent in degrees 
el_angle = 2; %serach volume elevation extent in degrees 
range = linspace(20e3,250e3,1000); % range to target from 20 Km 250 Km, 1000 points 
pap1 = power_aperture(snr,tsc,sigma/10,range,te,nf,loss,az_angle,el_angle); 
pap2 = power_aperture(snr,tsc,sigma,range,te,nf,loss,az_angle,el_angle); 
pap3 = power_aperture(snr,tsc,sigma*10,range,te,nf,loss,az_angle,el_angle); 
% plot power aperture prodcut versus range 
% figure 1.16a 
figure(1) 
rangekm  = range ./ 1000; 
plot(rangekm,pap1,'k',rangekm,pap2,'k -.',rangekm,pap3,'k:') 
grid 
legend('\sigma = -20 dBsm','\sigma = -10dBsm','\sigma = 0 dBsm') 
xlabel ('Detection range in Km'); 
ylabel ('Power aperture product in dB'); 
% generate Figure 1.16b 
lambda = 0.03; % wavelength in meters 
G = 45; % antenna gain in dB 
ae = linspace(1,25,1000);% aperture size 1 to 25 meter squared, 1000 points 
Ae = 10*log10(ae); 
range = 250e3; % rnage of interset is 250 Km 
pap1 = power_aperture(snr,tsc,sigma/10,range,te,nf,loss,az_angle,el_angle); 
pap2 = power_aperture(snr,tsc,sigma,range,te,nf,loss,az_angle,el_angle); 
pap3 = power_aperture(snr,tsc,sigma*10,range,te,nf,loss,az_angle,el_angle); 
Pav1 = pap1 - Ae; 
Pav2 = pap2 - Ae; 
Pav3 = pap3 - Ae; 
figure(2) 
plot(ae,Pav1,'k',ae,Pav2,'k -.',ae,Pav3,'k:') 
grid 
xlabel('Aperture size in square meters') 
ylabel('Pav in dB') 
legend('\sigma = -20 dBsm','\sigma = -10dBsm','\sigma = 0 dBsm')