Varying one of the many aerosol properties will force a change in the model radiance and polarization. The retrieval viability of a given aerosol property is based on how large these changes are compared with the measured radiance and polarization uncertainties. For radiance, the absolute (radiometric) uncertainty is estimated at 10%. The uncertainty in polarization is more complicated and can be determined using equation (3.3). For the geometry used, the uncertainty is approximately 0.03. (See section 3.2.1 for a discussion of the uncertainties.) An aerosol quantity is deemed retrievable to within the amount by which varying it will force a change in this quantity equal to the uncertainty.
All model calculations are made assuming no refraction.