cosang=38/63.5;   %cosine of the angle of camera sightline wrt laser beam.
r=(49-pos(2,:))/cosang;
z=251-pos(1,:);
theta=2*pi*pos(3,:);

x=r.*cos(theta);
y=r.*sin(theta);
t=pos(3,:);
 plot(t,y)
 shg