Mapping woody plant cover in desert grasslands using canopy reflectance modeling and MISR data. Chopping, M. J., Su, L., Laliberte, A., Rango, A, Peters, D., & Martonchik, J. Geophysical Research Letters, 2006.
Mapping woody plant cover in desert grasslands using canopy reflectance modeling and MISR data [pdf]Paper  abstract   bibtex   
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 wereobtained 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 overestimated as a result of the fixing of crown height and shape parameters.
@article{chopping_mapping_2006,
	title = {Mapping woody plant cover in desert grasslands using canopy reflectance modeling and {MISR} data},
	volume = {33},
	url = {http://www.agu.org/journals/gl/gl0617/2006GL027148/2006GL027148.pdf},
	abstract = {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 wereobtained 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 overestimated as a result of the fixing of crown height and shape parameters.},
	journal = {Geophysical Research Letters},
	author = {Chopping, M. J. and Su, L. and Laliberte, A.S. and Rango, A and Peters, D.C. and Martonchik, J.V.},
	year = {2006},
	keywords = {JRN, woody plant}
}
Downloads: 0