Spectral emissivity of northern land cover types derived with MODIS and ASTER sensors in MWIR and LWIR

Abstract

The purpose of this study is to evaluate the potential of satellite-derived emissivity in middle-wave infrared (MWIR) and long-wave infrared (LWIR) for land surface characterization. We compared emissivities derived from advanced spaceborne thermal emission and reflection radiometer (ASTER; temperature emissivity separation (TES) algorithm; validated data V003) and moderate resolution imaging spectroradiometer (MODIS; two different algorithms, classification-based emissivity method and day–night land surface temperature algorithm; provisional data V003) images acquired over northern Canadian regions. We observed disparities in emissivity dynamic range between each algorithm, and a bias also exists for the MODIS day–night algorithm (–0.02 versus ASTER). Lastly, we related MODIS and ASTER emissivity images with land cover type data derived from MODIS visible and near-infrared observations. Emissivity characteristics were determined for each class encountered. However, we generally observed a significant emissivity spatial heterogeneity inside a single land cover class.