www.pudn.com > programradarsystemdisign.zip > casestudy1_1.m

% This program is used to generate Fig. 1.17  
% It implements the search radar equation defined in Eq. 1.67 
clear all 
close all 
snr = 15.0;          % Sensitivity SNR in dB 
tsc = 2.;            % Antenna scan time in seconds 
sigma_tgtm = -10;    % Missile RCS in dBsm 
sigma_tgta = 6;      % Aircraft RCS in dBsm 
range = 60.0;       % Sensitivity range in Km,  
te = 290.0;         % Effective noise temprature in Kelvins 
nf = 8;             % Noise figure in dB 
loss = 10.0;         % Radar losses in dB 
az_angle = 360.0;   % Search volume azimuth extent in degrees 
el_angle = 10.0;    % Search volume elevation extent in degrees 
c = 3.0e+8;         % Speed of light 
% Compute Omega in steradians 
omega = (az_angle / 57.296) * (el_angle /57.296); 
omega_db = 10.0*log10(omega); % Convert Omega to dBs 
k_db = 10.*log10(1.38e-23); 
te_db = 10*log10(te); 
tsc_db = 10*log10(tsc); 
factor = 10*log10(4*pi); 
rangemdb = 10*log10(range * 1000.); 
rangeadb = 10*log10(range * 1000.); 
PAP_Missile = snr - sigma_tgtm - tsc_db + factor + 4.0 * rangemdb + ... 
   k_db + te_db + nf + loss + omega_db 
PAP_Aircraft = snr - sigma_tgta - tsc_db + factor + 4.0 * rangeadb + ... 
   k_db + te_db + nf + loss + omega_db 
index = 0; 
% vary rnage from 2Km to 90 Km  
for rangevar = 2 : 1 : 90 
   index = index + 1; 
   rangedb = 10*log10(rangevar * 1000.0); 
   papm(index) = snr - sigma_tgtm - tsc_db + factor + 4.0 * rangedb + ... 
      k_db + te_db + nf + loss + omega_db; 
  missile_PAP(index) = PAP_Missile; 
  aircraft_PAP(index) = PAP_Aircraft; 
   papa(index) = snr - sigma_tgta - tsc_db + factor + 4.0 * rangedb + ... 
      k_db + te_db + nf + loss +omega_db; 
end 
var = 2 : 1 : 90; 
figure (1) 
plot (var,papm,'k',var,papa,'k-.') 
legend ('Missile','Aircraft') 
xlabel ('Range - Km'); 
ylabel ('Power Aperture Product - dB'); 
hold on 
plot(var,missile_PAP,'k:',var,aircraft_PAP,'k:') 
grid 
hold off