HITRAN procedures for Igor

Collection of functions and procedures for loading data from the HITRAN database and simulating optical transmission through the atmosphere as a function of temperature, pressure and gas composition as well as thermal emission.

For more information about the HITRAN database, and to access the data files, go to:

Note that the free database does not include atmospheric data. This package includes composition data for just sea level atmospheric composition (from Wikipedia) and not a complete atmospheric model, nor is the GUI capable of combining multiple transmission layers. The framework is present, though and with some direct calls to the core calculation functions and input of temperature, pressure and composition data, multi-layer calculations can be coded.

There is no automated package installer: You should place the two procedure files into the user procedures folder (or a place a shortcut there) and the help file into the "Igor Help Files" folder (if you want it to load everytime) and invoke the procedures by adding

#include "HITRAN"

to the procedure window in an experiment. (The second procedure file, LineBroadening.ipf, is #included in the HITRAN file and can be downloaded separately as a stand alone Igor Exchange Project). Open the help file for more detailed setup instructions.

The package also includes a demo packed experiment file which can be run without any other downloads from the HITRAN site, although it only includes a small subset of the whole database.

Currently only line-by-line data is supported, but I plan to start incorporating other data that is available as well.
1. Access to the database (available for free and open to the public, they ask for your email and to fill out a questionnaire regarding intended usage)
2. Two files downloaded from the database (note the two different file paths: see below):
3. At least one file of line parameters (*.par files downloaded as compressed *.zip files. Individual molecules are available in *.par files named by their database index, or the entire database can be loaded from HITRAN2012.par)
4. Installation of MultiPeakFit.xop. I think this is now enabled by default on a new Igor installation, but it didn't use to be. If you get an error flagging LorentzianFit or VoigtFit as unknown objects, then enable the XOP by creating a shortcut to the file

C:\Program Files (x86)\WaveMetrics\Igor Pro Folder\More Extensions\Curve Fitting\MutliPeakFit.xop

and placing it in

C:\users\username\Documents\WaveMetrics\Igor Pro 6 User Files\Igor Extensions

(or the comparable folders on MacOS or older Windows versions)

*Parsum.dat (a file that contains partition function data for a range of temperatures) has not been updated for 2012. It's not clear if a newer version will be provided but if it is I would anticipate it showing up in the HITRAN2012/GlobalData/ directory.

Project Details

Current Project Release

HITRAN procedures for Igor IGOR.6.30.x-1.2

Release File: HITRANprocs_1_2.zip
Version: IGOR.6.30.x-1.2
Version Date: Sat, 08/17/2013 - 02:00 pm
Version Major: 1
Version Patch Level: 2
OS Compatibility: Mac-Intel Windows
Release Notes: Not a lot of changes on my end, but I had to tweak the parameter data loading routine to be compatible with the recently released HITRAN 2012 data and so decided to release an update. See HITRANhelp for a more complete list of changes.

In related news: HITRAN 2012 is out! New molecules and new isotopomers have been added and in order to use the new line database, you will have to run the initial setup procedure again (HITRAN->Setup->HITRAN Start) in order to regenerate the *.pxp versions of the data contained in molparam.txt and parsum.dat. Note that the new molparam.txt will be required:


whereas the partition data has not been upgraded (or even moved to the 2012 directory). The old version works and is still available at


Obviously, though, this means none of the new molecules / isotopomers have partition function data. They can still be used in simulations but the intensities will be wrong if the temperature is changed from 296K.
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I was trying to get these to work and the links for the parameters are parsnum files no longer work. Is there anyone that can update this? Do these procedures work for the newer HITRAN files?


Ryan Thalman




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