Py4CAtS --- Python for Computational ATmospheric Spectroscopy

lbl2od scheme
[Image: DLR]

Main Scripts/Functions: From Hitran/Geisa to cross sections to optical depths and radiance (intensity)

HItran-GeiSa extract (select) lines of a certain molecule (and isotope) and/or wavenumber range from line parameter database
line-by-line (lbl) cross sections for some molecule(s) and some p, T
computation of line-by-line optical depth due to molecular absorption (combines lbl2xs, xs2ac, ac2od)
Given the (layer, delta) line-by-line optical depth solve Schwarzschild equation to radiation intensity

Installation: Getting started with Py4CAtS

Download a tarball of Python sources, some data files, and the documentation and unpack it at some convenient place:
tar xfvz py4CAtS.tgz

The top-level directory py4CAtS includes a 1.ReadMe file with basic instructions, and four subdirectories bin, data, doc, and src.

Prerequisites: Python (3) and numpy (sometimes scipy and matplotlib for plotting)

And you need some line data (HITRAN and/or GEISA). For the beginning, here is a thermal infrared excerpt of Hitran 86.


Py4CAtS can be used in two ways, from the Unix/Linux (or Windows/Mac?) console/terminal or (much better, more flexible, ..... See the demo!NEW! or the poster for the ASA-HITRAN 2016 congress) inside the (I)Python interpreter or Jupyter Qt Console or notebook.


For a detailed review of line-by-line modeling for infrared radiative transfer see the manual py4cats.pdf in the doc directory.
Sections 5 and 6 describe Py4CAtS' usage from the Unix/Linux shell and the (i)python shell, respectively.

How to cite Py4CAtS?

(download BiBTeX entries)

What's new?

September 2019 -- January 2020
Module function loadxyy with new optional argument xLimits
Module cgsUnits: lengthsUnits: ly, pc added; functions lambda2nu, nu2lambda: first argument (wavelengths or wavenumbers) are variable list arguments
Module function Rautian now calling hum2wei32 (old: hum1wei24)
Module function show_lambda with new arguments frmt, yShift, nanometer
Module import show_lambda added;
Module functions oDepth_altitudes, oDepth_pressures optionally return altitudes or pressures in km, mb, ....
Module function xsSave: third and fourth arguments swapped (interpolate <--> commentChar)
function xsRead: now can be called recursively
July 2020
Module functions convolveBox, convolveTriangle, convolveGauss: the number of grid points for the new wGrid is now evaluated as int()
Module new module with some extra settings
Module last section with matplotlib settings removed (now in new file

© fgs   (+49-8153-28-1234)
Wed Oct 14, 2020; 12:34
Privacy Policy
Terms of Use