This repository contains the source code to reproduce the coronal holes segmentation model from the paper Segmentation of coronal holes in solar disk images with a convolutional neural network (published in MNRAS).
Try a demo running directly in the browser to see how the model will process solar disk images you will feed to it.
Clone the repo
git clone https://github.com/observethesun/coronal_holes.git
or download it as an archive.
For quickstart you need to have an archive of SDO/AIA 193 A jpeg images in 1K resolution that correspond to annotated coronal holes in date and time of observation and check that all required libraries are installed.
The repository is organized as follows:
src
folder contains the neural network architecture, methods for image loading and processing and classes that handle large datasets.notebooks
folder contains tutorials that explain how everything works. More detailed, you may needtrain_segmentation_model.ipynb
to reproduce the model training procedurerun_segmentation_model.ipynb
to test the model on SDO/AIA imagesconvert_images.ipynb
to convert.jpeg
images to more memory efficient.blosc
file format.
data
folder provides a daily archive of coronal holes (CHs) in.abp
file format. CHs were obtained from SDO/AIA 193 A images in 1K resolution for the period 2010 to 2018. These.abp
files are targets for the segmentation model. Visit http://observethesun.com/ to look at the distribution of CHs over the Sun.requirements.txt
contains a list of python libraries required to run the code.
.abp
is a text format used at the Kislovodsk Mountain Astronomical Station to describe active regions (in particular, coronal holes) isolated in solar disk images.
All .abp
files have similar structure:
- Filename contains date and time of the solar disk observation.
- First line of a file contains 7 numbers. First three numbers are x- and y-coordinates of the solar disk center and its radius given in pixel units. Last numbers are not important for CHs.
- Second line is not important for CHs.
- Third line contains a number of active regions.
- The rest lines are given by pairs of lines one for each active region. Pairs are organized as follows:
- first line contains 7 numbers, where the first one is an index of active region within the current file, second one in a number of pixels occupied by active region. Following numbers are not important for CHs.
- second line contains triples x, y, c one for each pixel within the active region. Here x, y are coordinates of pixel belonging to active region and c is a flag whether this pixel is inner (c=2) or edge (c=1) for the active region. Coordinates are in pixel units.
We suggest http://jsoc.stanford.edu/ for massive queries. For single images with preview consider http://suntoday.lmsal.com/suntoday/.
During the neural network training we read images from disk multiple times. However, I/O operation are known to be slow. To speed up the process we suggest to keep data in optimized formats that can be operated faster. Using .blosc
format one can have a speed benefit up to several times. Read more at http://blosc.org/.
Illarionov E., Tlatov А., 2018, MNRAS, 481, 4.
Using provided .abp
files in your research please cite
Tlatov A., Tavastsherna K., Vasil’eva V., 2014, Solar Physics, 289, 4.