4 column file, containing the Rahman, Pinty, and Verstraete (RPV) BDRF
parameterization Rahman1993.
rpv_file file
Bidirectional reflectance distribution functions for a variety of
surfaces are given in the paper. This option is only supported with
solvers: cdisort, fdisort2
and rte_solver
montecarlo (MYSTIC). The columns of the input file are wavelength
[nm], rho0, k, and theta. The parameters are interpolated linearly to
the internal wavelength grid. To make sure that the results are
reasonable, specify the RPV data on a wavelength grid similar or equal
to that used internally for the radiative transfer calculation!
Optionally, a fifth column with a constant scaling factor may be
defined. If it has seven columns, the fifth to seventh are sigma, t1,
t2, and if it has eight, the eighth is scale again.