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| Developed by the University of South Florida, exclusive distribution by Ontar Corporation |
| (Released September 10, 2009) |
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Click here
for a more complete description of HITRAN-PC and sample calculations (PDF file).
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Hitran-PC is a PC computer program that can calculate or model the high-resolution
( < 0.01 cm-1 ) optical transmission spectrum of the atmosphere and of selected
gases using primarily the HITRAN Line-by-Line database.
Hitran-PC has been developed over the past 20 years, with various levels of improvements and
capability, starting with Version 1.0 in 1991 through Version 3.0 in 2000.
The latest version, Hitran-PC 4.0, incorporates a major change and advancement in the program
and capabilities, and has been developed over the past several years.
It now uses the latest 2008 HITRAN Line-by-Line database, but also uses the
HITRAN UV and IR Cross Section files, the experimental PNNL IR database, aerosol extinction
using the BACKSCAT program, and the water vapor, CO2 and N2 Continuum.
The overall operation of Hitran-PC 4.0 is shown in the following figure.
As can be seen, the user can specify the path length, temperature, concentration, line
shape (Pressure, Voigt, etc.), and other parameters pertaining to the transmission of the
atmosphere. These startup parameters can also be stored in a configuration file for easy
use at a later time.
The startup parameters are then used along with atmospheric models of
pressure/temperature/altitude to model the geometry of the optical transmission path through
the gas or atmosphere. Both horizontal and slant path spectral calculations can be made.
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The databases and spectral calculations used by Hitran-PC 4.0 consist of:
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the main HITRAN Line-by-Line (LBL) database consisting of about several million individual
absorption lines of gases in the atmosphere (modeled with a spectral resolution greater
than 0.001 cm-1),
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the experimental PNNL database of environmental and chemical gases for about 400 gases
(with a spectral resolution on the order of 0.1 cm-1),
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the Continuum models for the far-wings of water vapor, CO2, and N2 that
add up to a few percent attenuation over a wide spectral range,
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the HITRAN cross section models that give the attenuation for UV and IR gases, and
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the BACKSCAT (Version 4.0) attenuation due to aerosols (clouds, fogs, dust, etc.),
for further use by the user.
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Numerous improvements have been introduced to Hitran-PC 4.0.
The most important of them are mentioned in this section.
- HITRAN 2004 and 2008 database usage http://www.hitran.com.
- Ability to carry out calculations for individual isotopes
- Addition of Aerosols Calculations
- Addition of HITRAN cross sections into calculations
- Automatic use of partial pressures from Standard atmospheres (both horizontal and slant
path calculations) for HITRAN cross sectional molecules
- Addition of PNNL IR Database into calculations
- Temperature and Molecular Partition Function routine updated
- Optional temperature scaling options for PNNL and HITRAN cross sections
- Ability to export calculations into multi-column TXT files
- Ability to automatically recalculate total pressure
- Laser line wavelength files updated
- Numerous interface improvements: Info Panel, Spectral Magnification, Copy-Paste feature
- US / European decimal numbers format differences now handled correctly
- Calculations now stored for each molecule and isotope before displaying spectra so
that plots can be expanded easily without subsequent re-calculation
Click here
for a more complete description of HITRAN-PC and sample calculations (PDF file).
Click here for pricing information.
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