CMEchaser wiki

CMEchaser looks for the occultation of background astronomical sources by CMEs, to enable measurement of effects such as variations in the ionised content and the associated Faraday rotation of polarised signals along the line of sight to the background source.

To do this CMEchaser transforms a given Galactic coordinate (with or without projected velocity) to its concordant point in the Helioprojective, Sun-centred plane and estimates the point at which the line of sight from the source to the Earth passes through it. It then searches a user selected database to detect if any CMEs which launched before the observation date would have crossed the line of sight at the epoch of observation.

For all such CMEs, it then produces two kinds of plots; the Quad plot containing polar depictions of all the CMEs and the position of the point at the line of sight punctures the Helioprojective plane and for each CME, a corresponding combined image of the LASCO+EIT observation closest to the launch epoch of the CME with the position of the point of puncture of the MDLOS overlaid.

There are two ways to use CMEchaser currently, the legacy method where CMEchaser runs as a flat script or a more modern version which can be installed as a package.

To use the legacy version:

Copy this repository to your computer with:

$ git clone https://bitbucket.org/golamshaifullah/cme_chaser.git

Getting set up:

In either case, we recommend creating a virtual environment to avoid changing your system python packages. CMEchaser was developed using conda environments, however any virtualisation system with the same dependencies should work.

Create a conda environment :

$ conda env create -f CMEchaser.yml

You might run in to problems with conda complaining about channels not found. Try this command to let conda find some of the 'experimental' packages sunpy needs.

$ conda config --append channels conda-forge

Then try :

$ conda activate CMEchaser_new

To use the package version

Currently the easiest method is to clone the repository and switch to the package branch as follows.

$ git clone https://bitbucket.org/golamshaifullah/cme_chaser.git
$ git checkout package

$ virtualenv cmechaser -p python3.5
$ python setup.py install

If you prefer to install cmechaser to your system packages, simply clone the repository and switch to the package branch and execute

$ pip install .

Testing the script itself

Try one of the commands in the legacy command examples or the package version in package command examples

Have fun!