System of astrometric databases of Pulkovo observatory. ... The purpose of these observations is the determination of precise coordinates of Solar system bodies, which is necessary for development and improvement of motion theories, and for studying the evolution of the Solar system. ... Accuracy of photographical observations is about 0.2-0.3 arcsec for equatorial coordinates and 0.1-0.3 for relative coordinates of planetary satellites, depending on object and observational conditions. ...