RFM Input Files


The first input file required is the Driver Table, which is always opened in the local directory with the filename 'rfm.drv'. The Driver Table determines the other input files.

Filenames listed in the Driver Table are transferred directly to a FORTRAN OPEN statement so are case-sensitive and should also include any relative directory information, e.g. './atm/std.atm'. The directory+name is also subject to the 200-character limit for any record read from the Driver Table.

It is suggested that the input files are distinguished by the 3-character extensions listed here, which correspond to the Driver Table Sections (eg *ATM) in which the filename is entered.

File Section Description Requirement
.atm *ATM Atmospheric Profiles mandatory
.spc *SPC Spectral axis or irreg.grid file optional
.gas *GAS List of Absorbers optional
.tan *TAN List of Tangent Heights optional
.cia *CIA Collision-Induced Absorption data CIA Flag
.fov *FOV Field-of-View data FOV Flag
.grd *GRD Irregular Grid Files GRD Flag
.hit *HIT HITRAN binary line data Any 'line' molecules
.ils *ILS Instrument Line Shape data ILS Flag
.nte *NTE Non-LTE data NTE Flag
.sfc *SFC Surface Emissivity spectral data SFC Flag
.svd *LUT SVD-compressed Look-Up Tables LUT Flag
.tab *LUT Abs.Coeff. Look-Up Tables LUT Flag
.xsc *XSC Cross-Section data Any 'cross-section' molecules
In the case of the optional files, the user may either supply the name of a file containing the necessary information, or enter the information explicitly in the appropriate section of the Driver Table. The file option may be useful, for example, for entering lists of absorbing species, or sequences of tangent heights corresponding to fixed scan patterns, whereas the direct Driver Table entry is more convenient for setting up simple runs.

For RFM-specific input files (i.e. excluding the .cia, .grd, .hit, .svd and .xsc files) the following principles apply:

  1. Files are ASCII, with maximum record lengths of 80 characters (anything beyond column 80 is ignored)
  2. Files may start with an arbitrary number of comment records, indicated by the first printable character being an exclamation mark '!'
  3. The first record of each file is copied to the rfm.log file, so should contain a comment giving some meaningful identification of the file contents and version.
  4. All text (apart from text used to form filenames) is case-insensitive - everything is converted to lower case within the RFM.
  5. Character fields may be delimited by spaces, tabs, commas or single quotes.
  6. Numerical fields are read free-format, so may be delimited by spaces or commas.