Inversion of the anomalous diffraction approximation for variable complex index of refraction near unity.

The Fymat analytic inversion method for retrieving a particle-area distribution function from anomalous diffraction multispectral extinction data tau and total area A is generalized to the case of a variable complex refractive index m(lambda) near unity depending on spectral wavelength lambda. Inversion tests are presented for a water-haze aerosol model. An upperphase shift limit of 5pi/2 retrieved an accurate peak area distribution profile. Analytical corrections using both the total number N and area A improved the inversion.