AVG Flag

RFM Flags: Spectral Averaging

26MAR24

Enabled
Output spectra represent spectral averages at the output grid spacing

Disabled
Output spectra represent spectral sampling at the output grid spacing (assuming the ILS Flag isn't enabled instead).

Restrictions
Incompatible with ILS, OPT and TAB Flags.

Notes
  1. This flag is a convenient way for performing spectral averaging (for example to reduce the net file size) without losing contributions from atmospheric fine spectral structure, which might happen if just sampling the spectra at too coarse a resolution.

  2. With this flag, the output spectra represent a convolution of spectra calculated on the RFM fine grid (see also FIN flag) with a triangular function of base = 2 x output resolution. Thus each fine grid point contributes to either 1 or 2 output points (1 if the fine grid point coincides with an output grid point, otherwise 2).

  3. The output spectral resolution is, as usual, specified in the *SPC section (RESSPC)

  4. The spectral averaging is performed by creating an internal 'instrument line shape' which is a triangle with a base width equal to twice the output resolution. This is equivalent to explicitly using the ILS Flag option and supplying such a triangular ILS as the .ils file.

Bugs
Bug#34 (Fixed v5.13)
Bug#31 (Fixed v5.13)