Spatial distribution of PM2.5 concentration based on aerosol optical thickness inverted by Landsat ETM+ data over Chengdu

This paper proposes a new method of spatial distribution of PM_2.5 concentration, which is based on Aerosol Optical Thickness (AOT) inverted by Landsat7 ETM+ Enhanced Thematic Mapper Plus (ETM+) data and PM_2.5 ground-based instruments. The main steps of the method are as follows:(1) Determination of dark pixels, search for the dark surface targets with the 2.2- μm channel; (2) Determination of the surface reflectance in the blue and red channels;(3) AOT retrieval, inverted from Look-up Tables (LUT) established from a set of atmospheric geometrical conditions;(4)Establish the model of PM_2.5 predicting with predictors and estimate the PM_2.5 value. The study results show that the method is an effective means for predicting the PM_2.5 concentration, and a beneficial supplement to the conventional ground-based measurement.