The maps in this directory (http://sdo.gsfc.nasa.gov/assets/mov/depot/DEMON/) are constructed using output from the Solar DEMON catalog: http://solardemon.oma.be/ The catalog is provided by the Royal Observatory of Belgium, Emil Kraaikamp and Cis Verbeeck. It performs automated detections of solar features. The maps in this directory are from the "Dimming detection on synoptic science data" component: http://solardemon.oma.be/science/dimmings.php The output of the DEMON dimming catalog are maps, movies, and metadata of dimmings that were detected in SDO AIA 211Å images (see Kraaikamp & Verbeeck, 2015, http://adsabs.harvard.edu/abs/2015JSWSC...5A..18K). There are two products in this directory: 1) The maps ending in "_map.png" (such as 20100523_1646_demon_4321_map.png) are masks of all the locations where the dimmings were detected. The value is 255 if a dimming was detected and 51 for the solar disk without dimming. Dimmings can be detected off the disk of the Sun. The coordinates are SDO Level so the 1.5 image coordinates (so they are coaligned but size of the Sun changes through the year), all derotated to the time of the first image. The final DEMON entry time and number of images in each sequence is shown in the top row, while the time of the first image in the sequence is shown in the second row. In general, the image cadence is one image every two minutes.2) The maps ending in "_tmap.png" (such as 20100523_1646_demon_4321_map.png) are color-coded to indicate the timing of the dimmings. Dark blue means that the pixel dimmed close to the start time of the sequence (second row of text at the top) while red shows the pixel dimming towards the end time of the sequence. A value of 128 indicates that the pixel registered a dimming detection during the first image in the sequence, while a value of 255 indicates that a pixel did not dim until the very last image in the sequence.
Here is a movie that shows the AIA images, the DEMON detection, and the assembly of the time map: http://sdo.gsfc.nasa.gov/assets/mov/depot/DEMON/00how_it_works.mov