Cosmic Ray Evaluation
- If you look hard enough you can find a cosmic ray hit in almost any magnetogram.
- Some cosmic rays are obvious, some look very much like small magnetic regions.
- It's not too useful to flag every image, so a subjective judgment is made to flag images with more obvious flaws.
- Each evaluator makes their own judgment and this may evolve in time.
- Fortunately the synoptic chart program eliminates most cosmic rays.
- Greater consideration is given to cosmic rays larger in size, stronger in value, and near the central meridian
- Any image with a large streak across it is flagged
- Any image with a visible cosmic ray near the center of the disk is flagged
- Any image with a cosmic ray near the limb is flagged if the cosmic ray is strong or obvious
- It is easier to see cosmic rays in the polar regions and the lower-noise 5-minute magnetograms.
DS9 will show the images for the day in a tiled form. Change to single image mode and step through the images for the day. Blinking back and forth shows the cosmic rays pretty quickly. Each evaluator may wish to set their own color table and other parameters.
Back to SynopticChartReductions