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Coronal Dimming Deployment

Science Testing Document

Input

The Coronal Dimming algorithm currently uses two 3-D Fits datacubes as input, one of which contains a time sequence of 2-D images, and the other containing the corresponding errors - so it uses a 3D datacube and a 3D error cube. The data cubes can be of any size (subject to computer memory restrictions). Currently the algorithm has only been tested on CDS data, therefore as the algorithm develops a seperate error cube may no longer be required as input, but the required errors may be derived from a single input datacube. The input datasets themselves remain unaltered by the processing.

Compilation and Execution:

  • compilation:
    The system uses standard GNU Make to compile and link the various modules. Prior to first compilation the Makefile needs to be modified to point to the fitsio include and library directories. After that, simply run Make:
    $ make all
  • commandline execution:
    $ CorDim datafilename [ errorfilename ]
  • datafilename: The name of the input 3D datacube fits file. Optionally contains the Statistical Error datacube. The pathname should be included if the datafile is in a different directory to where the executable, CorDim, is invoked from.
  • errorfilename (optional): The name of the input 3D datacube fits file. The pathname should be included if the datafile is in a different directory to where the executable, CorDim,is invoked from.
  • If there is no datacube containing the statistical errors, a poisson counting statistics cube is generated from the data cube, i.e. by taking the square root of the data.
  • AstroGrid workflow instructions:

Expected Output

  • final output:

  • The algorithm produces a FITS file containing the original image indicating the Coronal Dimming Region locations. Physical parameters extracted from the images are included as a fits table extension.

  • The new file is created in the same directory as the input file. The file will have "_coronal_dimm_out" inserted into the filename before the .fits extension

  • current level of completion:

  • The details for the current algorithm Is still being developed as the automated prediction rates although reasonable still need fine tuning so some of the functions are being changed. Also the code so far is hard wired to suit rastered CDS data. The next stage is to include the modifications currently being carried out by Danielle Bewsher, whose methodology this algortithm uses, and to make the algorithm more general in nature. Future work on the algorithm will also include development of the necessary IDL GUI components and their linking to the C-code executable.

Unit Testing

There are currently no unit tests available.

Science Test Cases

Case 1: CDS data on the limb

Description

The dimming algorithm was originally developed to identify dimming regions on the limb in CDS data. Limb only regions were chosen because they are the easiest to relate to the occurrence of coronal mass ejections.

For this test case, a dataset that covers the solar limb which has a known ‘deep’ dimming region has been chosen. The Mg IX data has been chosen from the CDS data as this best resembles the EIT 195 data which we will look at in Test Case 3.

Input

esdo_test1.sav contains a data cube called data – and an error cube called error. These are the 2 inputs to the coronal dimming algorithm.

Output

Images of the original data with the dimming region overlayed, and a txt file containing the parameters of the dimming region identified.

Case 2: CDS data on the disk

Description

For this test case, a region on the solar disk that has been observed by CDS has been chosen. Again, the Mg IX data has been chosen because it best resembles the EIT 195 data that we will look at in Test Case 3.

Input

esdo_test2.sav contains a data cube called data – and an error cube called error. These are the 2 inputs to the coronal dimming algorithm. The data has had the effect of solar rotation removed.

Expected Output

Images of the original data with the dimming region overlayed, and a txt file containing the parameters of the dimming region identified.

Case 3: EIT 195 Data

Description

The dimming algorithm has been developed so that dimming regions in full disk EIT images can also be identified. The user must specify whether they are inputting CDS or EIT data. If inputting EIT data, then the only input to the algorithm is a data cube. The errors are determined in a different way to CDS due to the different nature of the instruments.

An EIT dataset from 12th May 1997 that has already been shown to contain a dimming region by Podladchikova & Berghmans (2005) has been chosen.

Input

esdo_test3.sav contains a data cube called data. This is the only input into the dimming algorithm. The data has had the effect of solar rotation removed.

Expected Output

Images of the original data with the dimming region overlayed, and a txt file containing the parameters of the dimming region identified.

Case 4: CDS null example

Description

A CDS null test case has also been chosen to test error handling in the algorithm. A CDS limb dataset that does not contain a dimming region has been chosen.

Input

esdo_test4.sav – contains a data cube, data, and an error cube, error. These are the 2 inputs into the dimming algorithm.

Expected Output

Original data – with no dimming region overlayed. The txt file output will have a comment ‘No dimming region found’.

Results

Timing corresponding to test files esdo_test1.fits, esdo_test3.fits, and esdo_test4.fits is available at CoronalDimmingDeploymentResults.

Running the algorithm from AstroGrid

AstroGrid workflow instructions:

  1. Open AstroGrid workbench and click "Task Launcher"
  2. Tasks: find application, specify variables and file as input, specify files as output, launch
  3. Task Launcher search: coronal dimming or "Coronal Dimming Region Recognition"

-- ElizabethAuden - 04 Aug 2006

Topic attachments
I Attachment History Action Size Date Who Comment
Unknown file formatsav esdo_test1.sav r1 manage 4180.4 K 2007-01-17 - 15:31 UnknownUser Test data for coronal dimming test case 1
Unknown file formatsav esdo_test2.sav r1 manage 222.0 K 2007-01-17 - 15:36 UnknownUser Test data for coronal dimming test case 2
Unknown file formatsav esdo_test3.sav r1 manage 1282.1 K 2007-01-17 - 15:36 UnknownUser Test data for coronal dimming test case 3
Unknown file formatsav esdo_test4.sav r1 manage 1687.8 K 2007-01-17 - 15:36 UnknownUser Test data for coronal dimming test case 4
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Topic revision: r11 - 2007-12-20 - ElizabethAuden
 
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