# Figure 28. SINR Improvement Factor for the Optimum and Tapered Fully Adaptive STAP.

## Contents

```clc; clear; close all;
```

```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 Computation

```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)
```

## SINR Improvement Factor Calculation

```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.
ISINRopt = zeros(1,Lfd);
ISINRtap = zeros(1,Lfd);
InvRu = inv(Ru);
ksiin = sum(ksi) + sum(ksi_j) ;                           % Input Interference-to-Noise-Ratio on a single element for a single pulse.
SINRin = 1/(1+ ksiin);                                    % Eq. (121)
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;
ISINRopt(n) = w'*v/SINRin;                            % Eq. (124) for the Optimum Fully Adaptive Case.
ISINRtap(n) = abs(wtap'*v)^2/real(wtap'*gt)/SINRin;   % Eq. (124) for the Tapered Fully Adaptive Case.
end
```

## Plot the SINR Improvement Factors

```figure('NumberTitle', 'off','Name', ...
'Figure 28. SINR Improvement Factor for the optimum and tapered fully adaptive STAP',...
'Position', [1 1 600 500]);
plot(fd,10*log10(abs(ISINRopt)),'LineWidth',1.5)
hold on;
plot(fd,10*log10(abs(ISINRtap)),'r','LineWidth',1.5)
ylabel('SINR Improvement Factor (dB)');
xlabel('Target Doppler Frequency (Hz)');
ylim([45 76]);
xlim([-2 302]);