File with the center wavelengths and the wavelength band intervals to be used for
calculations in the thermal range.
thermal_bands_file file
The following three columns are expected:
center (or reference) wavelength, lower wavelength limit, upper wavelength limit [nm].
thermal_bands_file defines the wavelength grid for the radiative transfer
calculation. The RTE solver is called for each of the wavelengths in the first column.
The atmospheric (scattering, absorption, etc) properties are also evaluated at these
wavelengths. For thermal radiation calculations, the Planck function is integrated
over the wavelength bands defined in the second and third columns. The result will
therefore be a band-integrated irradiance which does only make sense when the
source solar file grid equals the thermal_bands_file grid.