Equation of Radiative Transfer Formal Solution

The equation of radiative transfer is an energy balance except for this concept, its physical content is slight. The phy.sical problems of interest enter through the extinction coefficient and the source function. Many papers and monographs have been written on its solution 

The formal solution of the equation of transfer is obtained by integration along a given path from the point s = 0 (Fig. 5.11)  

The source function J(s ) over the interval 0 to j must be known to evaluate the Integral in (5.47). 

When the medium extend.s to —oo in the s direction and there are no sources along s, it may be convenient not to stop the integration at the point 0 but to continue it indefinitely  

Thus the intensity obser ed at. t is the result of scattering by all of the particles along the line of sisht- 

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