|Rango, Albert - Al|
Submitted to: International Geoscience and Remote Sensing Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/20/2004
Publication Date: 9/20/2004
Citation: Chopping, M.J., Laliberte, A., Rango, A. 2004. Multi-angle data from CHRIS/PROBA for determination of canopy structure in desert rangelands. Proceedings of the International Geoscience and Remote Sensing Symposium. VII:4742-4745. Interpretive Summary: Interpretive summary not required for proceedings.
Technical Abstract: Multi-angle spectral radiance images from the Compact High-Resolution Imaging Spectrometer (CHRIS) on the European Space Agency's Proba satellite were acquired over desert grasslands in the USDA-ARS Jornada Experimental Range near Las Cruces, New Mexico, USA. The data were used to obtain multi-angle ratio images and to effect spatial bidirectional reflectance distribution function (BRDF) model inversions. The results show that there is canopy 3-D structure information observable in ratio images but physical interpretation is difficult. Inversion of a simple, nonlinear model for three canopy parameters resulted in low root-mean-square error values. The difficulty of decomposing the effects of brightness and reflectance anisotropy (BRDF shape) in complex desert shrub landscapes with varying soil-understory characteristics was overcome by allowing linear scaling of the parameters of the soil-understory submodel as a function of near-nadir 631 nm reflectance. The retrieved parameter maps show a high spatial correlation between width and height but a different distribution for density. Examination of high-resolution panchromatic and multispectral imagery shows that there are strong relationships between the retrieved parameters and canopy characteristics although further validation is required.