Aiming at estimating parameters that have a physical meaning related to the properties of vegetation, biophysical parameter retrieval is an approach in remote sensing for assessing vegetation status, e.g. physical properties, growth, and health. These biophysical products are useful for a wide range of thematic areas such as crop monitoring and food security applications; forest, water, and natural resources management; land carbon modeling, and weather and climate forecasting. Important biophysical parameters describing vegetation include leaf area index (LAI), the green cover fraction (fCover), the fraction of absorbed photosynthetically active radiation (fAPAR), plant height, and biomass.
Methods to retrieve the biophysical parameters from remote sensing data fall into two main categories.
- Statistical models empirically match data to a biophysical variable. These include techniques measuring a vegetation index and combining the measurements at different wavelengths to one or more biophysical parameters.
- Physically-based modeling is an alternative approach that uses advanced radiative transfer models to describe the transfer and interaction of radiation inside a leaf or canopy based on robust physical, chemical, and biological processes. They compute the interaction between solar radiation and plants and provide a better understanding between biophysical variables and reflectance characteristics. (University of Twente, n.d.)
Explore below some common examples of vegetation biophysical parameters.
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