Radar Cross Section (RCS) - MATLAB Simulations for Radar Systems Design - page 582

sigma = 0:0.001:6;
sigma_bar = 1.5;
swer_3_4 = (4. / sigma_bar^2) .* sigma .* ...
exp(-2. * (sigma ./ sigma_bar));
%t.*exp(-(t.^2)./2.
swer_1_2 = (1. /sigma_bar) .* exp( -sigma ./ sigma_bar);
plot(sigma,swer_1_2,'k',sigma,swer_3_4,'k');
grid;
gtext ('Swerling I,II');
gtext ('Swerling III,IV');
xlabel ('sigma');
ylabel ('Probability density');
title ('sigma-bar = 1.5');