% Int2RayJean(i,f)
%
%    Convert intensities to "Rayleigh-Jeans" temperatures using the
%    Rayleigh-Jeans scaling factor.
%
%    The frequency and intensity vectors/matrices must have the 
%    same size.
%
% FORMAT   invrayjean(i,f)
%        
% OUT   tb   brightness temperatures [K]
% IN    i    intensities [W/m^2Hz]
%       f    frequencies [Hz]

% 2002-12-12   Created by Claudia Emde.


function tb = invrayjean(i,f)

boltzmann = constants('BOLTZMANN_CONST');
speed_light = constants('SPEED_OF_LIGHT');

tb = speed_light^2/(2*f^2*boltzmann) * i;