Figure 27. SINR Loss for the Fully Adaptive STAP.

Contents

% Coded by Ilias Konsoulas, 16 Sept. 2018.
% Code provided for educational purposes only. All rights reserved.

clc; clear; close all;

Radar System Operational Parameters

radar_oper_params;

Thermal Noise Power Computation

thermal_noise_power;

Thermal Noise Covariance Matrix

Rn = sigma2*eye(M*N);

Clutter Patch RCS Computation

clutter_patch_rcs;

Calculate the Array Transmit and Element Receive Power Gains

Tx_Rx_power_gains;

Calculate the Clutter to Noise Ratio (CNR) for each clutter patch

ksi = Pt*Gtgain.*Grec*lambda^2*sigma/((4*pi)^3*Pn*10^(Ls/10)*Rcik^4);   % Eq. (58)

Clutter Covariance Matrix Computations

beta = 1;   % beta parameter.
phia = 0;   % Velocity Misalignment Angle.

Rc = clutt_cov(ksi,beta);

Jamming Covariance Matrix Calculation

jamm_cov;

Total Interference Covariance Matrix

Ru = Rc + Rj + Rn;                                        % Eq. (98)

SIRN Loss (LSINR) Calculations

ta = chebwin(N,30);                                       % 30 dB Chebychev Spatial Tapper.
tb = chebwin(M,40);                                       % 40 dB Chebychev Doppler Taper.
t = kron(tb,ta);
phit = 0; thetat = 0;                                     % Target Azimuth and Elevation Angles.
fspt = d/lambda*cos(thetat*pi/180)*sin(phit*pi/180);      % Target Spatial Frequency.
fd = 0:.5:300;   Lfd = length(fd);
omega = fd/fr;
a = exp(1i*2*pi*fspt*(0:N-1));                            % Target Spatial Steering Vector.
LSINRopt = zeros(1,Lfd);
LSINRtap = zeros(1,Lfd);
InvRu = inv(Ru);
SNRo = M*N;                                               % Eq. (119)
for n=1:Lfd
    b = exp(1i*2*pi*omega(n)*(0:M-1));                    % Dummy Target Doppler Steering Vector
    v = kron(b,a).';
    gt = t.*v;
    w = InvRu*v; %#ok<*MINV>
    wtap = InvRu*gt;
    LSINRopt(n) = w'*v/SNRo;                              % Eq. (120) for the Optimum Fully Adaptive Case.
    LSINRtap(n) = abs(wtap'*v)^2/real(wtap'*gt)/SNRo;     % Eq. (120) for the Tapered Adaptive Case.
end

Plot the SINR Losses

figure('NumberTitle', 'off','Name', 'Figure 27. SINR Loss for the Fully Adaptive STAP',...
       'Position', [1 1 600 500]);
plot(fd,10*log10(abs(LSINRopt)),'LineWidth',1.5)
hold on;
plot(fd,10*log10(abs(LSINRtap)),'r','LineWidth',1.5)
ylabel('SINR Loss (dB)');
xlabel('Target Doppler Frequency (Hz)');
ylim([-30 1]);
xlim([-2 302]);
legend('Optimum Fully Adaptive', 'Tapered Fully Adaptive', 'Location','South')
grid on;