The radiation field measurements using a polarimeter and a multispectral radiometer can be used to infer the equivalent optical parameters of aerosol particles. The importance of this experiment lies in the fact that radiative effects of particulates can be calculated without ambiguity if these effective parameters are known. In addition to providing illustrative examples of the derivation of atmospheric parameters from radiation measurements, a critical discussion of the implications underlying these model calculations are given so that the physical significance and the usefulness of these experi-ments can be better appreciated.