Analysis of a Time-Varying Scene Observed with a Digital CCD Camera

The analysis of digital solar flare images obtained with a CCD camera, their representation in graphical form, and the various corrections (calibrations, image motion, atmospheric conditions) to be applied to the data are presented. Specially treated is the description of time-varying scenes and the possibility of reducing the information of the two-dimensional images to one value in order to study photometric parameters as a function of time. It is discussed in detail how original raw data can be restored by Fourier-filtering techniques in space and time yielding an almost noise-free light curve. All data analysis has been done on a large general-purpose computer and not on a specialized picture analysis system which usually is not commonly available. Though the object of our study is the sun, the analysis presented here is equally well applicable to any two-dimensional digital image.