*HIT Section

RFM Driver Table Sections: HITRAN line data

01FEB24
Type
Optional Section, depends on whether HITRAN 'line' molecules (ID#1:99) are selected

Description
HITRAN line parameter data, in various forms

Format
Single field.
FieldTypeDescription
HITFIL C200 Name of .bin or .par File
From RFM v4.21 onwards, while the old form will continue to be supported, the recommended form is a series of records each containing a PARAMETER=VALUE structure, with optional qualifiers attached to the VALUE field. Here the order of the records is significant
Parameter Value Type Description
BINFIL= HITFIL C200 Name of a HITBIN-generated binary .bin File
PARFIL= HITFIL C200 Name of a standard HITRAN line parameter .par File
HDBFIL= HITFIL C200 Name of an extracted HITRAN database .hdb File
Qualifier Type Description Units
(GAS(1); GAS(2); ... ) C Molecules to be included from file
(-GAS(1); GAS(2); ... ) C Molecules to be excluded from file
(WNOMIN:WNOMAX) D Wavenumber range of file cm-1

Notes
  1. The *HIT section is optional if all 'line' molecules are represented by Look-Up Tables instead, but since you are likely to have only one version of the HITRAN data then you might as well keep the *HIT section in the driver table anyway (data available in LUTs takes precedence).

  2. The .par file is the 160-character record format that can be downloaded from the HITRAN web-site.

    Changes from RFM v5.21 onwards (allowing for multiple files)

  3. With multiple files the RFM assumes by default (i.e., if you don't use any qualifiers) that the later files take precedence, e.g. if H2O is contained in the both the first and second files, only H2O line data from the second file will be used. This means that if you have a specialised HITRAN file for a particular molecule you should list it after the 'standard' file.

  4. Reading the .par file can be quite slow, so a faster alternative is to convert the .par file to an RFM-specific binary format (.hit file) using the the HITBIN program (although, having said that, I've not noticed any significant difference in time, at least not on my desktop).

  5. With .par and .hdb files the RFM first has to read through the file to determine which molecules are or are not present in the file, and check that the file covers the required spectral range. In these cases it is quicker to use qualifiers to tell the RFM what to assume the file contains (this is not an issue with the .bin file since all the required information is in the file header and forward pointer records).

Example
*HIT hitran_2012.hit ! HITRAN 2012 data

Bugs
[none reported]