Author
Schmugge, Thomas | |
French, Andrew | |
OGAWA, KENTA - HITACHI LTD |
Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 7/1/2002 Publication Date: 9/16/2002 Citation: Schmugge, T.J., French, A.N., Ogawa, K. 2002. Quantitative estimates of emissivity using ASTER data [abstract]. Recent Advances in Quantitative Remote Sensing Symposium. p. 121. Interpretive Summary: Technical Abstract: A new tool for observing land surface properties is now available, i.e. multispectral thermal infrared (TIR) data from the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer. ASTER has 5 channels in the 8 to 12 micrometer wave band with 90 meter resolution. These data can be used to assess the spectral variations of surface emissivity. Knowledge of the surface emissivity is important for determining the radiation balance at the land surface. This is significant for arid lands with sparse vegetation because the emissivity of the exposed soils and rocks is highly variable. The results we will present are from ASTER data acquired over the Jornada Experimental Range in New Mexico during 2000 and 2001. The Temperature Emissivity Separation (TES) algorithm is used to extract the temperature and 5 emissivities from the 5 channels of ASTER data. In spite of the 90 m resolution, the results agree well with laboratory measurements of the emissivity for the quartz rich soils of the site with values < 0.85 for the 8 - 9 micrometer channels. For the longest wavelength channels little spatial variation of the emissivity was observed with values of 0.96 ± 0.005 over large areas. The White Sands National Monument with its dunes of gypsum sand was also observed. Emissivity values from the ASTER data for 3 scenes for the gypsum were in good agreement with values calculated from the lab spectra and with each other. The results for vegetated targets show little or no spectral variation with emissivities > 0.97. |