Continental-scale validation of MODIS-based and LEDAPS Landsat ETM+ atmospheric correction methods

The potential of Landsat data processing to provide systematic continental scale products has been demonstrated by several projects including the NASA Webenabled Landsat Data (WELD) project. The recent free availability of Landsat data increases the need for robust and efficient atmospheric correction algorithms. This study compares the accuracy of two Landsat atmospheric correction methods: a MODIS-based method and the Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) method. Both methods are based on the 6SV radiative transfer code but have distinctly different atmospheric aerosol characterization approaches. The MODIS-based method uses the MODIS Terra derived dynamic aerosol type and optical thickness to atmospherically correct ETM+ acquisitions in each coincident orbit. The LEDAPS method uses aerosol characterizations derived independently from each Landsat acquisition and assumes a fixed continental aerosol type. Validation results are presented comparing ETM+ atmospherically corrected data generated using these two methods with each other and with AERONET corrected data at 102 10km x 10km sites centered on AERONET sites located across the conterminous United States. The results indicate that the MODIS-based method has better accuracy than the LEDAPS method for all the ETM+ reflective bands.