Collages of Granulation Pictures

摘要

One of the best techniques available to solar astronomers for obtaining a sharp picture is to take a burst of photographs with short exposures during moments of good seeing. The astronomers then selects the best frame within the burst by eye. If a movie is desired, a series of bursts is taken and the astronomer selects those frames that will form the movie. With the advent of the CCD array with its digital output, one can do this selection process automatically with a computer. In addition, since the sharpness varies over the scene, the comptuter could extend the selection process to small areas and then, after a suitable time(the order of a few seconds), could assemble all the best pieces into a final picture representing the best image that occured during the burst. This reprint describes two small-area selection schemes that we have applied to CCD observations of solar granulation.