PROJECT TITLE :

Development and Validation of a Robust Algorithm for Retrieving Aerosol Optical Depth Over Land From MODIS Data

ABSTRACT:

Because of the limitation of surface “dark-target,” in some regions and over certain surface varieties, Moderate Resolution Imaging Spectroradiometer (MODIS) commonplace aerosol algorithm does not work terribly well. During this paper, we have a tendency to developed and validated a strong algorithm, which combines the revised minimum reflectance technique and the technique of the synergy of Terra and Aqua MODIS to eliminate the dependence on surface conditions. The rationale of our algorithm is to first establish the “clearest” day observations in sure temporal window, assume that the aerosol optical depth (AOD) does not amendment during the restricted period (0-three h) between Terra and Aqua overpass during this day, subsequently acquire the relationships between visible bands and a pair of.1 μm band surface reflectance, and finally retrieve the AOD of all observations within the temporal window. The algorithm was validated using year 2006 measurements from 13 Aerosol Robotic Network (AERONET) sites distributed in North China, Central Asia, jap United States, and Western Europe. For AOD, 65.fivep.c and 72.sevenpercent of retrievals among MOD04 expected error envelope for all levels of quality assurance confidence (QAC) and QAC = three, respectively, R2 of 0.87 and a less amount of gaps are found. In comparison to the MODIS aerosol merchandise, the new algorithm on the full shows similar accuracy over dark land surface, but gives a larger amount of retrievals over bright land surface. This indicates that the new algorithm can provide a more steady inversion for a variety of surface sorts. Especially over urban surface, such as Beijing in China, the inverted AOD is clearly better than that from MODIS aerosol merchandise. Therefore, the new algorithm can provide another way for AOD retrieving over regions where the quality dark target algorithm will not work well or higher spatial resolution is imperative.