Quickstart for thermal mode

Usage

Usage in a shell script

if libradtranpy/src/libradtranpy/libsimulateThermal.py is in the python path:

libsimulateThermal.py [-v] -z <airmass> -w <pwv> -o <oz> -p <P> -c <cld> -m<mod> -q<proc> -s<site-string> -v<verbose-flag>

  • z : airmass from 1.0 to 3.0, typical z=1

  • pwv : precipitable watr vapor in kg per m2 or mm, typical pwv = 5.18 mm

  • oz : ozone in Dobson units from 200 DU to 400 DU

  • p : Pressure in hPa, typical P=775.3 hPa

  • c : Cloud vertical optical depth, typical c=0

  • m : Atmospheric model, typical m=’us’

  • q : Interaction processes, typical q=’sa’ for scattering and absorption

  • s : provide site or altitude as a string : LSST/OHP/PDM/OMK/OSL or altitude in km like akm_2.663

  • v : activate libradtran output verbose mode

  • t : thermal output selected among (brightness,radiance,irradiance,irradiance_integrated,transmisstance). Optional. Default brightness

Examples :

  1. python libsimulateThermal.py -z 1 -w 0 -o 0 -s LSST

  2. python libsimulateThermal.py -z 1 -w 4 -o 300 -c 0 -p 742 -m us -q sa -s LSST -t irradiance

To generate ascii printout of the used atmospheric model tables in a log file :

python libsimulateThermal.py -v -z 1 -w 0 -o 0 -s LSST >& output.log

Actually provided :

Number of arguments: 2 arguments. Argument List: [‘libsimulateThermal.py’, ‘-v’]

Outputs of libradtran

  • Librandtran generates output acii files consisting of rows of (wavelength, transmission).

  • librandtranpy manages the different simulations and their output files in a hierarchical directories. The top level directory is simulations/.

The output of libradtran can be found in subdirs of simulations/RT/2.0.5/observationsite/pp/.

  • note airmass is useless in thermal mode (see radiance for directional flux)

Use of libradtranpy as python package library

The call of libradtran through libradtranpy can be done as follow:

from libradtranpy import libsimulateThermal

path,thefile=libsimulateThermal.ProcessSimulation(am[index],pwv,ozone,pressure,

prof_str=’us’,proc_str=’sa’,cloudext=cloudext,altitude_str=”LSST”,thermal_output=”brightness”)

where the argument thermal_output specifies the type of output required among : * sky brightness (temperature) * irradiance, * integrated irradiance, * radiance, * transmittance.

  • path,thefilename are the path and filename of the output ascii file.

The result of the simulation can be obtained by:

data = np.loadtxt(os.path.join(path,thefile)) wl = data[:,0] atm = data[:,1]

Two examples of images are shown below:

_images/thermalsim_cld_brightness.png
_images/thermalsim_cld_multiirradiance.png

More examples are given in notebooks.

Remarks on the documentation on readthedocs

As libRadtran is not installed on readthedocs computer, the following example below cannot appear.

The access is shown as follow:

These are detailed in API Documentation.

Moreover the libradtranpy.libsimulateThermal API cannot appear on readthedocs website. This API may appear on user’s computer if libRadtran is installed correctly.