Aerosol optical depth retrievals from high-resolution commercial satellite imagery over areas of high surface reflectance
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Authors
Vincent, Dominick A.
Subjects
Aerosol
Satellite Observations
Aerosol Optical Depth Retrieval
Over Land
Shadow
High-Resolution Commercial Satellite Imagery
QuickBird
Desert
Urban
Grass
High Surface Reflectance
Satellite Observations
Aerosol Optical Depth Retrieval
Over Land
Shadow
High-Resolution Commercial Satellite Imagery
QuickBird
Desert
Urban
Grass
High Surface Reflectance
Advisors
Durkee, Philip A.
Date of Issue
2006-06
Date
June 2006
Publisher
Monterey, California.: Naval Postgraduate School, 2006.
Language
Abstract
The advancement and proliferation of high-resolution commercial imaging satellites presents a new opportunity for overland aerosol characterization. Current aerosol optical depth retrieval methods typically fail over areas with high surface reflectance, such as urban areas and deserts, since the upwelling radiance due to scattering by aerosols is small compared to the radiance resulting from surface reflection. The method proposed here uses shadows cast on the surface to exploit the differences between radiance from the adjacent shaded and unshaded areas of the scene. Given uniform surface reflectance for the shaded and unshaded areas, the difference in reflected radiance measured by a satellite sensor is related to the direct transmission of solar radiation and inversely proportional to total optical depth. Using an iterative approach, surface reflectance and mean aerosol reflectance can be partitioned to refine the retrieved total optical depth and, ultimately, determine the aerosol optical depth. Initial results based on QuickBird imagery and AERONET data collected during the UAE2 campaign, as well as archive imagery and AERONET data for four other cities, indicate that aerosol optical depth retrievals are possible in the visible and near-infrared region with an uncertainty of ﾫ0.04 for areas with surface reflectance values of 0.15 (15%) or greater.
Type
Description
Series/Report No
Department
Department of Meteorology.
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
xxvi, 169 p. : col. ill. ; 28 cm.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.