clear
lambda=[302,325];
Hozone=5000; 
m0=0.19;

%[I1,I01]=RTE(lambda(1),m0);
%[I2,I02]=RTE(lambda(2),m0);
%I2/I1
%return
el=[2:2:30];
m0=1./airmass(el);
%m0=[0.5:-0.05:0.05];
for i=1:length(m0)
    [I1(i),I01(i)]=RTE(lambda(1),m0(i),Hozone);
    [I2(i),I02(i)]=RTE(lambda(2),m0(i),Hozone);
end    
%plot(m0,I2./I1)
plot(90-el,I2./I1,'s')
hold on
plot(90-el,I2./I1)

xlabel('Solar Zenith Angle')
ylabel('\lambda_2/\lambda_1')
title(['Umkehr \lambda_1 = ',num2str(lambda(1)),'; \lambda_2 = ',num2str(lambda(2))])