Improved cloud and snow screening in MAIAC aerosol retrievals using spectral and spatial analysis
An improved cloud/snow screening technique in the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm is described. It is implemented as part of MAIAC aerosol retrievals based on analysis of spectral resid- uals and spatial variability. Comparisons with AERONET aerosol observations and a large-scale MODIS data analy- sis show strong suppression of aerosol optical thickness out- liers due to unresolved clouds and snow. At the same time, the developed filter does not reduce the aerosol retrieval ca- pability at high 1 km resolution in strongly inhomogeneous environments, such as near centers of the active fires. De- spite significant improvement, the optical depth outliers in high spatial resolution data are and will remain the prob- lem to be addressed by the application-dependent specialized filtering techniques.