期刊名称:ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN:2194-9042
电子版ISSN:2194-9050
出版年度:2010
卷号:XXXVIII - Part 7B
页码:424-429
出版社:Copernicus Publications
摘要:One of the main challenges of current climate research is providing Earth-wide characterization of Aerosol Optical Depth (AOD), which indicates the amount of depletion that a beam of radiation undergoes as it passes through the atmosphere. Here, a comprehensive overview will be presented of our ongoing data mining based study aimed at better understanding of spatio-temporal distribution of AOD by taking advantage of measurements collected from multiple ground and satellite-based sensors. In contrast to domain-driven methods for AOD retrieval (prediction from satellite observations), our approach is completely data-driven. This statistical method consists of training a nonlinear regression model to predict AOD using the satellite observations as inputs where the targets are obtained from a network of unevenly distributed ground-based sites over the world. Challenges and our proposed solutions discussed here in context of global scale AOD estimation include (i) AOD regression from mixed-distribution spatio- temporal data; (ii) training such a statistical predictor for robust performance across multiple accuracy measures; (iii) uncertainty analysis of AOD estimation, (iv) active selection of sites for ground based observations, (v) discovery of major sources of correctable errors in deterministic models, and (vi) using conditional random fields to combine nonlinear regression models and a variety of correlated knowledge sources in a unified and more accurate AOD prediction model. The proposed methods is illustrated on experiments conducted using three years of global observations obtained by merging satellite data of high spatial resolution (MODIS Level 2 data from NASA's Terra and Aqua satellites) with ground-based observations of high temporal resolution (a remote-sensing network of radiometers called AERONET network). The experiments revealed that the proposed methods result in more accurate AOD retrieval than the baseline statistical and domain-based predictors
关键词:Atmosphere; Environment; Analysis; Data Mining; Retrieval; Algorithms; Spatial; Temporal