Abstract
This work examines the application of a geometric-optical canopy reflectance model to provide measures of woody shrub abundance in desert grasslands at the landscape scale. The approach is through inversion of the non-linear simple geometric model (SGM) against 631 nm multi-angle reflectance data from the Compact High Resolution Imaging Spectrometer (CHRIS) flown on the European Space Agency's Project for On-Board Autonomy (Proba) satellite. Separation of background and upper canopy contributions was effected by a linear scaling of the parameters of the Walthall bidirectional reflectance distribution function model with the weights of a kernel-driven model. The relationship was calibrated against a small number of sample locations with highly contrasting background/upper canopy configurations, before application over an area of about 25 km2. The results show that with some assumptions, the multi-angle remote sensing signal from CHRIS/Proba can be explained in terms of a combined soil-understory background response and woody shrub cover and exploited to map this important structural attribute of desert grasslands.
Original language | English |
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Pages (from-to) | 62-73 |
Number of pages | 12 |
Journal | Remote Sensing of Environment |
Volume | 104 |
Issue number | 1 |
DOIs | |
State | Published - 15 Sep 2006 |
Keywords
- Canopy reflectance
- Dessert grasslands
- Geometric-optical
- Modeling
- Multi-angle remote sensing
- Semi-arid environments
- Woody shrub encroachment