% Knife edge diffraction for a half-plane which is at the distance hc from the line of sight.  
% -hc is for the knife edge below the LOS, hc is for above
% use trapezoidal integration
% Hc=hc*sqrt(2*d/(lambda*d1*d2

hcc=-5;
inc=.01;
for k=1:1000
    Hc=hcc+k/100;
    height(k)=Hc;
    u=[];
    u=Hc:inc:90;
    y(k)=abs(inc*trapz(exp(-1j*pi*(u.^2)/2)))/sqrt(2);
end
figure;
plot(height,y,'k')
xlabel('H_c')
ylabel('F_d')

clear all