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Air pollution control and air quality monitoring are global priority, which also applies to local scales. Ground-based monitoring stations provide high quality values, but their number and cost make them insufficient for use at certain scales and for air monitoring in urban areas. Satellite imagery provides indicators directly related to air quality. Aerosol optical thickness (AOD), used in atmospheric corrections of images, can be used as an indicator of air quality. This product is present in images obtained by satellites of medium spatial resolution, so it is necessary to develop methodologies to obtain it at higher resolution. This work aims to compare methodologies for obtaining AOD and its use in high spatial resolution satellites. [ABSTRACT FROM AUTHOR]

Surface reflectance retrieval is an important step in the data processing chain for the extraction of quantitative information in many applications areas. The aim of this paper is to develop a new method for retrieving surface reflectance and aerosol optical depth simultaneously over both dark vegetated surfaces and bright land surfaces. After applying this new model to the Moderate Resolution Imaging Spectroradiometer (MODIS) data in the Heihe River Basin of China, aerosol optical depth and surface reflectance values of these regions are calculated. The retrieved surface reflectance from MODIS is consistent with measured reflectance from Analytical Spectral Device (ASD) Field Spec spectral radiometer, and the root mean square error (RMSE) are; Band 1 (0.66µm): 0.027; Band 3 (0.47µm): 0.015; Band 4 (0.55µm): 0.017. The R-squared (R2) value reveals a good agreement between MOD09 and retrieved surface reflectance at band 1. The RMSE of the reflectance value differences are quite small; Band 1: 0.031; Band 3: 0.026; Band 4: 0.029. [ABSTRACT FROM PUBLISHER]

In this paper, an analytical strategy is presented to retrieve jointly aerosol optical depth (AOD) and surface reflectance (R) from geostationary satellites. The new algorithm is based on a parameterization of the atmospheric radiative transfer model. Taking AOD and R as unknown parameters and based on some reasonable assumptions of AOD's spatial consistence and R's temporal invariance, both parameters of each pixel can be derived. Applying this algorithm to data from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) observations on board Meteosat Second Generation (MSG), we obtain regional maps of AOD and R from two adjacent observations. Preliminary validation results by comparing our retrieved AOD with Aerosol Robotic Network (AERONET) data show good accuracy, and retrieved R is also reasonable. This method is potential to be applied in instantaneously monitoring aerosol spatio-temporal variation using geostationary satellite sensors with only one single visible channel and high-frequency observations. [ABSTRACT FROM PUBLISHER]

Despite the fact that commercial optical very high spatial resolution satellite imagery has been available for more than 10 years, very little research has been done to take advantage of its multi-temporal and multi-angular information. In this paper, the benefits of using surface reflectance for the analysis of multi-temporal and multi-angular images are discussed using a 23 image time-series acquired between 2002 and 2010 by QuickBird and WorldView-2 over the city of Denver, Colorado. Results show that it is possible to extract useful information from multi-angular data regarding the structure of specific objects. [ABSTRACT FROM PUBLISHER]

Aerosol optical depth (AOD) retrieval from satellite remote sensing is essential to understand aerosol influence on earth climate system. An algorithm to retrieve AOD from geostationary earth orbit (GEO) satellite allows us to monitor sources, sinks and transport of aerosols in higher temporal resolution. In this study, using 30-day visible channel data from the Multi-Functional Transport Satellite-1 Replacement (MTSAT-1R) to estimate surface reflectance and DIScrete Ordinate Radiative (DISORT) model (6 S) to calculate look up tables (LUT), AODs are retrieved at 0.55 μm over East Asia. The retrieved results are compared with the values of AERONET and MODIS. The calculated correlation coefficient(R) during March 2006 with AERONET showed 0.85 at Anmyon and 0.40 at Shirahama. The R for MODIS ranged from 0.2 to 0.96. This algorithm has relatively larger retrieval error than other multiple-channel algorithm due to the limitation in characterizing surface reflectance and aerosol property. [ABSTRACT FROM AUTHOR]