CHMAP: Coronal Hole Mapping and Analysis Pipeline

CHMAP is a python package focused on the detection, mapping, tracking, and general analysis of coronal holes in the solar corona.

CHMAP includes methods for:

• Data Acquisition
• Data Reduction
• Limb Brightening Correction
• Inter-Instrument Scaling
• Flexible Map Creation
• Coronal Hole Detection
• Coronal Hole Tracking

Although CHMAP was designed for analyzing coronal hole evolution from seconds to years, many of the database, image processing, and mapping procedures are relevant a broad range of solar features and scientific analysis.

Requirements

This package requires a custom python environment that includes Sunpy.
At time of writing the version of Sunpy (3.1.6) available from the conda-defaults channel is fatally flawed. So be sure that the conda-forge channel is added to your conda preferences before using the enclosed conda recipe file. Check for conda-forge:

conda config --show channels

If needed, add conda-forge:

conda config --append channels conda-forge

Now we are ready to build the custom 'chmap' conda environment:

conda env create --file conda_recipe_chmap.yml

Raw data reduction steps may also require SSW/IDL (for STEREO/EUVI) and a GPU deconvolution algorithm.

Database

CHMAP uses database methods (SQLite, MySQL) to facilitate flexible interaction with solar imaging data and their byproducts (maps, time-series, etc).

Create your own database using CHMAP or use our example database, which includes sample data and 14+ years of data-derived image correction coefficients (5.7GB).

Additionally, we have processed EUV and coronal hole maps every 2 hours for 2008-2020. These can be viewed using the CHMAP Database Browser.

Documentation and Examples

Pipeline documentation and examples can be found here: predsci.github.io/CHMAP.

Acknowledgements

Copyright 2021 Predictive Science Incorporated (Apache 2.0 License).

A research paper describing the initial release of CHMAP and some applications is currently in preparation. In the meantime, if you use CHMAP code or concepts in your own work, please refer to our prior work on this topic (Caplan et al., 2016) and cite the corresponding Zenodo release for CHMAP: .

The development of CHMAP was primarily supported by the NASA Heliophysics Guest Investigators program (grant NNX17AB78G). Additional support is from the Heliophysics Supporting Research program (grants 80NSSC18K0101 & 80NSSC18K1129).

Contact

Cooper Downs (cdowns@predsci.com)

Contributors

• Cooper Downs
• James Turtle
• Tamar Ervin
• Opal Issan
• Ronald M. Caplan
• Jon A. Linker