RFM Flags

BBT Flag: Write Brightness Temperature Spectra


Create .bbt files containing brightness temperature spectra, i.e. the temperature [K] of the Planck Function that gives the equivalent spectral radiance.
If *BBT section present in Driver Table, read user-defined filename.

No brightness temperature spectra written
*BBT section ignored.

Incompatible with TAB Flag.

  1. Internally the RFM calculates radiance, these are converted to brightness temperature [K] at the output stage (subroutine wrtout.for) using the inverse of the Planck function, i.e:
             BBT = C2 * ν / LOG ( 1 + C1 * ν**3 / RAD ) 
    where C1,C2 are the radiation constants, approx 1.191E-3 nW/(cm2 sr (cm-1)4) and 1.439 K/cm-1 respectively (actual values in phycon.inc, or in phycon_dat.f90 for RFM v5.0 ), ν is the wavenumber [cm-1], RAD is the radiance [nW/(cm2 sr cm-1)].
  2. See also the Rayleigh-Jeans Temperature, which is closely related to BBT, and converges as ν → 0.
  3. See RFM Outputs for default filename(s).

Bug#60 (Fixed v4.26)