The Wide-Field Plate Database
Milcho Tsvetkov, Katya Tsvetkova and Nikolai Kirov
Bulgarian Academy of Sciences

The Wide-Field Plate Database (WFPDB) as a basic source of data for the wide-field astronomical photographic plates stored worldwide, is presented. The Catalogue of Wide-Field Plate Archives comprises 476 plate archives with more than 2.4 million plates. The Catalogue of Wide-Field Plate Indexes contains up to September 2011 the parameters of 563 600 plates from 133 archives with provided possibilities for data search, quick plate preview with low resolution in JPEG files of some of the plates and complete plate image with high resolution in FITS files upon request. The technology developed in Sofia for plate digitization by commercial high-quality flatbed scanners is presented, too. The Data Bank of Digitized Plate Images contains images with low resolution for quick plate visualization and easy online access, and with high resolution aiming photometric and astrometric investigations. Links to online services and cross-correlation with journals and other catalogues characterize the development to photographic plate libraries.