absorption_bandsReadHITRAN

Workspace.absorption_bandsReadHITRAN(self, absorption_bands: pyarts.arts.AbsorptionBands | None = None, file: pyarts.arts.String | None = None, frequency_range: pyarts.arts.Vector2 | None = None, line_strength_option: pyarts.arts.String | None = None, compute_zeeman_parameters: pyarts.arts.Index | None = None) → None

Reads HITRAN data from a file.

The HITRAN file is assumed sorted in frequency, with each line record filling up one line of text.

If the full 160-char line record is consumed without reaching the end of the line, qns’ and qns’’ are assumed appended with default HITRANonline format.

You may pass an inclusive frequency range to limit what is read. This will limit the data read to the range [fmin, fmax]. All data before fmin is limited to parsing just up until the frequency, and the database is returned if the fmax frequency is exceeded.

The optional parameter einstein_coefficient is used to indicate if it is to be computed from the line strength, or simply read from the Hitran data.

Warning

Several HITRAN lines has Einstein coefficients that will not reproduce the results of pure line strength simulations. If the option is set to read the Einstein coefficicent (“A”) instead of computing it (“S”) the program will throw an error if missing data is encountered. For the computed Einstein coeffcient, if the upper degeneracy is missing, it will be set to either - (2J+1) or -1 if J is not a local quantum number. Note that this will also make the Einstein coefficient negative. This should not affect the simulation, but it is a warning that the data is not complete.

Author(s): Richard Larsson

Parameters:

  • absorption_bands (AbsorptionBands, optional) – Bands of absorption lines for LBL calculations. See absorption_bands, defaults to self.absorption_bands [OUT]

  • file (String) – Filename. [IN]

  • frequency_range (Vector2, optional) – Frequency range selection. Defaults to -inf inf [IN]

  • line_strength_option (String, optional) – Whether the Hitran line strenght or the Hitran Einstein coefficient is used, the latter has historically been less reliable. Defaults to "S" [IN]

  • compute_zeeman_parameters (Index, optional) – Compute the Zeeman parameters from the HITRAN data (will not activate Zeeman calculations, this must be done manually afterwards). Defaults to 1 [IN]