HISTORY OF OBSERVATORY

The Observatory at Borowiec was founded as a part of the Department of Astronomy of the Polish Academy of Sciences under the name of the Astronomical Latitude Station in the mid-fifties in order to work on determination of the polar motion, time correction and maintenance of the time standard UTC. These tasks were realised in cooperation with the Bureau International de l'Heure (BIH) with the help of two visual zenith telescopes and two transit instruments and quartz clocks constructed at Borowiec. Gravimetric measurements were conducted periodically.

In the mid sixties the Observatory was incorporated as a part of the Institute of Geophysics of the Polish Academy of Sciences, and in 1972 its name was changed into Astronomical Latitude Observatory. In 1964 the staff of the Observatory in cooperation with the Astronomical Observatory of the Adam Mickiewicz University in Poznan started observations of the artificial Earth satellites, at first by a simple photographic camera PO-1, then its improved version PO-3, later replaced by a high quality SBG camera made by C. Zeiss Jena.

In 1976 the laser measurements of distances to the satellites were started by a satellite laser ranging system of the Intercosmos type. Till 1983 the measurements with the help of the Intercosmos laser ranging were carried out with the accuracy of 70 cm. From 1983 the satellite measurements were performed by the Doppler technique using own DOG-2 receivers.

In 1977 the Observatory together with the Department of Planetary Geodesy was included into the Space Research Centre of the Polish Academy of Sciences, founded in the same year.

The time base was modernized by introduction of the cesium frequency standard Rhode & Schwarz (1980) and connection to the international time system by the television method which ensured the time accuracy of below 1 microsecond and allowed the access of the Borowiec Observatory into creation of the international atomic time scale TAI.

Starting from 1982 the classical measurements of the Earth rotation were continued with the use of Danjon astrolab which replaced the outdated transit instruments and visual zenith telescopes.

In 1988 regular measurements were begun with the use of the second generation satellite laser ranging system designed and constructed in cooperation with the Astronomical Observatory of the Adam Mickiewicz University in Poznan. In 1991 a third generation laser CONTINUUM PY-62 was installed which improved the accuracy of the measurements of the distances to satellites to 1 cm.

In 1993 the Doppler observations were abandoned and instead the Global Positioning System (GPS) observations started. Since 1994, when a GPS TURBO ROGUE SNR-8000 receiver was installed, the Observatory has been included into the network of the International GPS Service for Geodynamics (IGS).

The measurements with the help of the laser system and GPS method allowed the Observatory in Borowiec to continue the cooperation with the International Earth Rotation Service (IERS) on determination of the Earth rotation. At the same time the time service was equipped with the cesium frequency standard OSCILLOQUARTZ EUDICS 3020 which in connection with the LORAN-C receiver constructed at the Observatory and than with the GPS time receivers ensured the time recording accuracy of the order of 10 ns. The time service at the Observatory is currently engaged in creation of the atomic time scale TAI and UTC in the cooperation with the Bureau International des Poids et Mesures (BIPM). Also in the nineties the gravimetric measurements were resumed. Since 1983 the works on VLBI and satellite interferometry, and since 1992 the works on determination of position of moving objects (planes, cars, ships) by the DGPS (Differential GPS) have been continued.

In 1995 the name of the Observatory was changed to the Borowiec Astrogeodynamic Observatory.