This is the fraction of radiation - entering the canopy via the reference plane at the top-of-canopy - that has been absorbed by those scatterers in the scene that are labelled as foliage elements i.e., needles or leaves irrespective of whether they are represented as turbid or discrete objects wihtin the scene. In fabs_fol, absorption events by 'wood' components and the background surface are excluded.
This measure applies to all scene in RAMI-V and only the bands included in the Photosynthetically
Active Radiation (PAR) spectral region (400-700 nm). Hence in RAMI-V they are O03 (442.5nm), O04(490nm), O06(560nm), O08(665nm), O10(681.25nm).
Illumination to be considered are either direct illumination as defined in brfpp, as well as isotropic diffuse.
|absorption by the canopy foliage||%.6f|
|standard deviation of fabs_fol estimate*||%.6f|
*: if available, otherwise set to −1.000000.