Retrieval of aerosol optical properties from multi-angle satellite imagery

摘要

The authors have been investigating a novel method for retrieving atmospheric aerosol optical properties over land. The described method makes use of the presence of spatial contrasts, within the imagery, and compares the spatial Fourier transforms of the multiangle images at zero and nonzero spatial frequencies. An initial guess for the aerosol properties is made and the Fourier components of the surface reflectance distribution are retrieved at zero and nonzero frequencies. A comparison of the angular shape of the retrieved functions is then used to establish whether the initial guess for the aerosol parameters was correct. Other than the need to define a relationship between the angular variation of the Fourier transform of the intrinsic surface angular reflectance at the zero and nonzero frequencies, the method assumes no prior knowledge about the aerosols or surface characteristics. The authors discuss sensitivities to various aerosol properties.