5.5.1 - LSA SAF FVC

The estimation of FVC is based on the analysis of K0 for VIS 0.6 μm, VIS 0.8 μm and NIR 1.6 μm channels. The K0 component of surface reflectance is the less affected by shadows and, therefore is able to provide a physically correct estimation of FVC. Taking into account the spectral signature of pure types of vegetation (V1,V2,V3) and soil (S1,S2,S3), the SMA process allows to estimate the fraction of the vegetation types present in the pixel.
Next figure shows an example, considering a 2 dimensional space [0.8 μm K0 and 0.6 μm K0 ]


FVC_06_08

Therefore FVC is estimated by the following expression:


FVC_expression

Pure vegetation types consider species prevalent in:

  • V1 - Crops
  • V2 - Herbaceous ecosystems
  • V3 - Forest

Soil types include:

  • S1 - Bare soil
  • S2 - Rock
  • S3 - Human-built surfaces

Next figure shows an example of FVC over the Full SEVIRI disk (figure on the left), and the corresponding Error (figure on the right) for the 15th April 2007.

FVC_and_Error

The FVC image adequately captures the spatial patterns of vegetation cover at continental level. Large spatial variation gradients are observed over Africa. This figure also highlights the spatial homogeneity and the absence of large gaps in the FVC field.