RFM Flags

BBT Flag: Write Brightness Temperature Spectra

14JUN18

Enabled
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.

Disabled
No brightness temperature spectra written
*BBT section ignored.

Restrictions
Incompatible with TAB Flag.

Notes
  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 = c2ν / ln ( 1 + c1ν3 / 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_dat.f90), 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).

Bugs
Bug#60 (Fixed v4.26)