The optimal information system contained in the digitized photographic plates and CCD
by
Liviu Serbanescu
Astronomical Institute of Romanian Academy

The images obtained from digitization of photographic plates or directly from CCD camera is put in a standard graphic format, compressed or uncompressed. After the image processing, the result is stocked in a standard graphic format (the most common formats are FITS and TIFF). Each time when is necessary to obtain new information, the image must be reanalyzed. When a comparison with other images (of the same area) is made, the whole set of images must be reanalyzed. Besides, in the processing moment, some information with a certain level of uncertainty may be existing. Because of those aspects, it is necessary to exist a representing system of the information for any area which contains, for each image, at least the following elements: the position of the celestial object, the shape (after the reducing operation in comparison with the other objects from same image), the variation of the light intensity, the uncertainly level of each information that has been inferred. Beside that, the final image will contain not only results obtained from "mixing" of all images from that area, but also the information from catalogues. Practically, these representing systems, judged from the point of view of obtained data, will be formed by two subsystems: a static subsystem - that

contains data for each image and a dynamic subsystem - resulted by the inquiries of the static subsystem that will contain the "mixing" result of all images and catalogue data. From the functional point of view, the system will contain the data part and the dynamic inquiries part, made in such way that the update of all databases to be made automatically. So, the user is seeing the whole system as a relational database, that can be accessed directly by him, or by other software applications and so the image files are no more used.

Date received: February 28, 2005