There are many thousands of astrometric positions of the first eight Saturn satellites. Stugnell & Taylor (1990) present a catalogue of ground-based observations taken between 1874 and 1989, with more than 51000 observations. Later, Harper & Taylor (1994) analyze an extensive catalog of these positions, Hyperion excluded. The theoretical positions were computed using the theory of the motion of the Saturn satellites (Harper & Taylor 1993). From the residuals of more than 9000 photographic intersatellite positions made by 46 different authors, it is observed that about 20% are larger than 03, about 30% lay between 02 and 03, and the remaining 50% are smaller than 02. As remarked by the authors, the data sets for Mimas and Hyperion are particularly sparse.
In 1982 we started a systematic program of astrometric observations of satellites of the Jovian planets. Our results about the Uranus and Neptune systems were published in previous papers (see for example Veiga & Vieira Martins 1995, 1998). In this, paper we report the results from 138 photographic plates of the Saturnian system carried out during 30 nights distributed in 12 observational missions, in the period from 1982 to 1988. The positions for the first eight satellites are given. This set constitutes the totality of our Saturnian photographic observations. In 1989 we swept to a CCD detector and the results from this observations will be published in a forthcoming paper.
The present paper is organized as follows. In Sect. 2 the observations and reduction procedures are described and the differential coordinates of seven Saturn satellites referred to Titan are presented. In Sect. 3 our results are compared with theoretical calculated positions, as given by the theory TASS1.7 (Vienne & Duriez 1995; Vienne & Duriez 1998) for the eight major satellites.
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