Wide-field Astrometry Service

Since its foundation, the Spanish Navy Observatory has conducted studies and scientific works in the field of Photographic Astrometry.

The Gautier Astrograph has been a unique element to carry out observations in that field. Since late nineteenth, when it was acquired, this astrograph was used in two of the most important international astronomical projects in the late nineteenth and early twentieth centuries, the Carte du Ciel (CdC) and Astrographic Catalogue (AC). Therefore, in collaboration with the Centro de Investigaciones de Astronomía (CIDA, Venezuela), the digitization of all plates of those catalogues has been carried out in two positions rotated 90 degrees in order to eliminate systematic errors. Thus the information contained in those plates is now available in electronic format (FITS) for further processing and application to the calculation of proper motions.

At the beginning of this century, the Gautier Astrograph was modernized with an Apogee Alta U9 (3 k X 2 k) CCD camera of 9 microns per pixel fitted with a Sloan r' filter. This, together with the development of a new image-observation and image-reduction software, has made possible to have an instrument suitable to conduct observations for scientific and educational purpose, despite the poor conditions of the sky of San Fernando. Moreover, with the adoption of the research project Astrometric Positioning of Artificial Geostationary Satellites (PASAGE) in 2004, a research in the determination of the precise positions of objects in geostationary orbit has been conducted. The results were published in Advances in Space Research review (F.J. Montojo, T. López Moratalla, C. Abad, Astrometric Positioning and Orbit Determination of Geostationary Satellites, ASpR no. 47, pp 1043-1053, 2011).

Another important observational instrument is the Baker-Nunn Camera (BNCs), designed and constructed by the Smithsonian Institution in the early Space Age as the American solution for tracking the first artificial satellites. The USA placed 12 of these BNCs all over the world to have global coverage and in 1958 one of them was installed at this Observatory. It was operative until 1979, when BNCs were superseded by newer technologies (laser, radar and CCDs) and the San Fernando BCN was donated to ROA, where it has been maintained inactive but in excellent state of conservation until 2002 when it was refurbished by a project carried out by the RACAB jointly with the ROA.

The project consisted in a complete transformation of the ROA's BCN that exploits the excellent mechanical and optical original design to obtain an equatorial telescope with a useful 4.4deg x 4.4deg CCD field of view to carry out remote and robotic astrometric observations. Once the refurbish was finished, the telescope, now renamed as Telescope Fabra ROA at Montsec (TFRM), was installed at the Montsec Astronomical Observatory (OAdM) in the Catalonian Pyrenees (Northeast of Spain).

TFRM was inaugurated on September 16th, 2010 and at this moment it remains in commissioning period.