The ExPRES models CMI (Cyclotron Maser Instability) driven radio emissions. It provides radio dynamic spectra observed from a defined location. Since the CMI emission process is very anisotropic, the relative geometry of the radio source and the observer drives the observability of the source. More info on the ExPRES code: ExPRES on the MASER web site. The code can be launched from the MASER run on demand interface.

Reference: Louis et al., ExPRES: a Tool to Simulate Exoplanetary and Planetary Radio Emissions, A&A 627, A30 (2019)

• src contains the ExPRES code IDL routines.
• mfl stores the magnetic field lines used by ExPRES. When installing the code, precomputed data files must be retrieved from http://maser.obspm.fr/support/expres/mfl. See this file for more details.
• ephem stores ephemerides files used by ExPRES. IDL saveset files (.sav) are available for precomputed ephemerides. Other files (plain text format, .txt) will be stored here, and correspond to the output of the MIRIADE IMCCE webservice calls.
• cdawlib is a placeholder for the NASA/GSFC CDAWLib library, required for the CDF files.

The config.ini.template file (in src) must be renamed config.ini and edited with the adequate paths:

• cdf_dist_path must point to the local CDF distribution directory.
• ephem_path is the path to the directory where the precomputed ephemerides files are located, and where temporary ephemerides files will be written.
• mfl_path is the path to the directory where the precomputed magnetic field line data.
• save_path is the path where the data will be saved.
• ffmpeg_path points to the ffmpeg executable, e.g., /opt/local/bin/ffmpeg
• ps2pdf_path points to the ps2pdf executable, e.g., /opt/local/bin/ps2pdf

Examples are provided in the header of config.ini.template.

The code has been tested under IDL 8.5. You must have a functional installation of IDL 8.5 (or better) on your system.

The IDL interpreter must be configured to look for routines into the src and cdawlib directories.

The operation are initiated with the following batch script:

IDL> @serpe_compile

This compiles all the necessary routines in advance. Then the simulation can be launched:

IDL> main,'file.json'

where file.json is the input parameter file. This file must comply with the ExPRES-v1.3 JSON-shema