www.pudn.com > programradarsystemdisign.zip > fig2_21.m

% Use this program to reproduce Fig. 2.20 of text. 
close all 
clear all 
np = 4; 
pfa = 1e-7; 
pdm = 0.99945; 
pda = 0.99812; 
% calculate the improvement factor 
Im = improv_fac(np,pfa, pdm); 
Ia = improv_fac(np, pfa, pda); 
% caculate the integration loss 
Lm = 10*log10(np) - Im; 
La = 10*log10(np) - Ia; 
pt = 114.7e3; % peak power in Watts 
freq = 3e+9; % radar operating frequency in Hz 
g = 34.5139; % antenna gain in dB 
sigmam = 0.5; % missile RCS m squared 
sigmaa = 4; % aircraft RCS m squared 
te = 290.0; % effective noise temperature in Kelvins 
b = 1.0e+6; % radar operating bandwidth in Hz 
nf = 6.0; %noise figure in dB 
loss = 8.0; % radar losses in dB 
losstm = loss + Lm; % total loss for missile 
lossta = loss + La; % total loss for aircraft 
range = linspace(20e3,120e3,1000); % range to target from 20 to 120 Km, 1000 points 
% modify pt by np*pt to account for pulse integration 
snrmnci = radar_eq(np*pt, freq, g, sigmam, te, b, nf, losstm, range); 
snrm = radar_eq(pt, freq, g, sigmam, te, b, nf, loss, range); 
snranci = radar_eq(np*pt, freq, g, sigmaa, te, b, nf, lossta, range); 
snra = radar_eq(pt, freq, g, sigmaa, te, b, nf, loss, range); 
% plot SNR versus range 
rangekm  = range ./ 1000; 
figure(1) 
subplot(2,1,1) 
plot(rangekm,snrmnci,'k',rangekm,snrm,'k -.') 
grid 
legend('With 4-pulse NCI','Single pulse') 
ylabel ('SNR - dB'); 
title('Missile case') 
subplot(2,1,2) 
plot(rangekm,snranci,'k',rangekm,snra,'k -.') 
grid 
legend('With 4-pulse NCI','Single pulse') 
ylabel ('SNR - dB'); 
title('Aircraft case') 
xlabel('Detection range - Km')