l=1.3;
k=2*pi/l;
x1=.0:1/11:2;
a=4;
x=a.*x1;
r=length(x);



a2=.896:.04:(r-1)*.04+.896;
s2=a.*a2;
a1=.89 :.04:.04*(r-1)+.89 ; 
s1=a*a1;

%sig=s1./s2;
sig=ones(1,r)

%z1=2.5:2.5:r*2.5;
z1=zeros(1,r);
z=a.*z1;
%theta1=0:2: (r-1)*2;
theta1=zeros(1,r);
theta=(pi/180).* theta1;
s11=s1.^2;
p=k^2.*s11;
g=k*z./p;
g2=g.^2;
f=k*x./p;
f2=f.^2;
d=sin(theta);
d1=d.^2;

q=g.^2+(sig+1).^2;
u=(sig+1).*f2+2*sig.*(sig+1).*f.*sin(theta)+sig.*(g2+sig+1).*d1;
c0=4*sig./q;
y=p.*u./q;
n0=1;n1=1.47;
t2=16*(n1*n0)^2/(n1+n0)^4;
t1=t2*c0.*exp(-y);
w=-10*log10(t1);
plot(x1,t1)

