Geodetski list, Vol. 55 (78) No. 2, 2001.
Original scientific paper
Analysis of Scientific Results Obtained in Geodetic Positioning of the Hvar Observatory
Miljenko Solarić
; Faculty of Geodesy, University of Zagreb, Zagreb, Croatia
Nikola Solarić
; Faculty of Geodesy, University of Zagreb, Zagreb, Croatia
Abstract
The paper presents the analysis of the scientific results obtained in geodetic positioning of the Hvar Observatory, Faculty of Geodesy at the University of Zagreb. The first, there were the results of Doppler measurements at the Hvar Observatory analysed in the campaigns IDOC'82 (1982) and WEDOC-2 (1983) and mutually compared. Then, the results obtained in GPS measurements with the instruments having Pi code and two frequencies (by means of phase measurements) were analysed. In order to compare the results of Doppler positioning of the Hvar Observatory with the results of GPS measurements, Doppler determinations had to be transformed from the WGS'72 co-ordinate system in WGS'84 (the old) system and after that to the ITRF'90 datum. The analysis thus carried out indicates that the position co-ordinates of the Hvar Observatory determined almost 20 years ago by means of Doppler measurements:
– with precise ephemerides by co-ordinates with the accuracy better than 1 m, and by ellipsoid height about 0,75 m and
– with broadcast ephemerides from the satellites by the co-ordinates X and Y better than 1 m, and by the co-ordinate Z the accuracy runs up to 2,5 m to 2,9 m, i.e. 4,8 m.
Hence, it can be stated that the Hvar Observatory (trigonometer 209Z) was the most accurately determined point in Croatia almost 20 years ago, and in the farmer state as well, with great efforts invested for its more and more accurate determination doping with the development of modem measuring technology. At the end, there were vertical deflections determined at the Hvar Observatory, as well as the geoid height.
Keywords
Doppler measurements; ellipsoidal heights; geoidal heights; GPS measurements; co-ordinates; co-ordinate systems; WGS'72; WGS'84; ITRS; ITRF'yy; ETRF'89; deflections of vertical
Hrčak ID:
290733
URI
Publication date:
30.6.2001.
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