Scripps Institution of Oceanography

SIO Reference 57-51. In this note, we exhibit the formulation of the requisite statements of the four tijne-dependent principles of invariance and show that they are sufficient todorivethe functional relations governing the tine-dependent R and T functions and their corresponding integral operator. The derivations follow closely the pattern used in some earlier studies of the stationary case, in this way we add to the evidence that the classical procedures initiated by Chandrasekhar can be extended to more general setting For brevity the present discussion is limited to plane-parallel media. However the media will be assumed finite, non-separable, and such that the attenuate and scattering functions are generally dependent on time.