Hydrology and Land Surface Studies
Mapping woody plant cover in desert grasslands using canopy reflectance modeling and MISR data
Article first published online: 9 SEP 2006
Copyright 2006 by the American Geophysical Union.
Geophysical Research Letters
Volume 33, Issue 17, September 2006
How to Cite
2006), Mapping woody plant cover in desert grasslands using canopy reflectance modeling and MISR data, Geophys. Res. Lett., 33, L17402, doi:10.1029/2006GL027148., , , , , and (
- Issue published online: 9 SEP 2006
- Article first published online: 9 SEP 2006
- Manuscript Accepted: 31 JUL 2006
- Manuscript Revised: 26 JUL 2006
- Manuscript Received: 7 JUN 2006
 A simplified geometric-optical model (SGM) was inverted using red band reflectance data acquired at 275 m in nine viewing angles from the Multiangle Imaging SpectroRadiometer (MISR) flown on NASA's Terra satellite, to provide estimates of fractional woody plant cover for large areas (over 3519 km2) in parts of the Chihuahuan Desert in New Mexico, USA. The use of the model in these semi-arid environments was enabled by the derivation of a priori estimates of the soil/understory background reflectance response. This was made possible by determining relationships between the kernel weights from a LiSparse-RossThin model adjusted against the same MISR data – together with spectral reflectance data derived from MISR's nadir-viewing camera – and the parameters of the Walthall model used to represent the background. Spatial distributions of retrieved fractional woody plant cover match those of % tree cover in the global MODIS Vegetation Continuous Fields product but also include shrubs. Good relationships were obtained with fractional shrub cover measured in pastures in the USDA, ARS Jornada Experimental Range but tree cover in higher elevation and riparian zones was dramatically over-estimated as a result of the fixing of crown height and shape parameters.