Lowtran in Python
LOWTRAN7 atmospheric absorption extinction model. Updated to be platform independent and easily accessible from Python and Matlab.
The main LOWTRAN program is accessible from Python by using direct memory transfers instead of the cumbersome and error-prone process of writing/reading text files.
xarray.Dataset high-performance, simple N-D array data is passed out, with appropriate metadata.
See below for how to make these examples.
Lowtran requires a Fortran compiler and CMake.
f2py (part of
numpy) to seamlessly use Fortran libraries from Python by special compilation of the Fortran library with auto-generated shim code.
If a Fortran compiler is not already installed, install Gfortran:
apt install gfortran
brew install gcc
- Windows: Windows Subsystem for Linux
Install Python Lowtran code
pip install -e .
In these examples, optionally write to HDF5 with the
We present Python examples of:
ground-to-space transmittance: TransmittanceGround2Space.py
sun-to-observer scattered radiance (why the sky is blue): ScatterRadiance.py
sun-to-observer irradiance: SolarIrradiance.py
observer-to-observer solar single-scattering solar radiance (up-going) with custom Pressure, Temperature and partial pressure for 12 species: UserDataHorizontalRadiance.py
observer-to-observer transmittance with custom Pressure, Temperature and partial pressure for 12 species: UserDataHorizontalTransmittance.py
observer-to-observer transmittance: HorizontalTransmittance.py
Matlab users can seamlessly access Python modules, as demonstrated in RunLowtran.m.
Here's what's you'll need:
Install Lowtran in Python as at the top of this Readme.
From Matlab, verify everything is working by:
LOWTRAN7 User manual Refer to this to understand what parameters are set to default. Currently I don't have any aerosols enabled for example, though it's possible to add them into the code.
Right now a lot of configuration features aren't implemented, please request those you want.
- Original 1994 Lowtran7 Code
LOWFILprogram in reference/lowtran7.10.f was not connected as we had previously implemented a filter function directly in Python.
LOWSCANspectral sampling (scanning) program in
reference/lowtran7.13.fwas not connected as we had no need for coarser spectral resolution.