Local Ties at Fundamental Stations
In this article we discuss and give an example of three different methods to measure the local tie between the IGS GPS antenna reference point (ARP) and the VLBI antenna reference point at the Metsähovi fundamental station. First we introduce traditional survey approach combined with a space intersection technique and then local tie based on kinematic GPS during geo-VLBI campaigns and finally local ties with static GPS measurements. We discuss the measurements and computations, problems and error sources encountered between the planning of the measurements and the end product, the local tie vector. Although millimetre precision can be achieved, our experience during tests at Metsähovi fundamental station shows that some techniques are very time consuming and impractical for a routine use. We aim for a more automated process in local tie measurement.
Based on our experiments and results, we propose that in the future, the VLBI antenna tie could be tracked permanently during geo-VLBI campaigns with attached GPS antennas.
KeywordsGeodetic ties VLBI GPS Fundamental stations
The authors would like to thank the personnel of the Aalto University Metsähovi Radio Observatory for their invaluable help. This project was partly funded by the Academy of Finland, decision number 134952.
- Bilker-Koivula M, Ollikainen M (2009) Suomen geoidimallit ja niiden käyttäminen korkeuden muunnoksissa, Geodeettinen laitos, tiedote 29, 2009 (in Finnish)Google Scholar
- Dach R, Hugentobler U, Fridez P, Meindl M (eds) (2007) Bernese GPS software, version 5.0. Astronomical Institute, University of Bern, 612ppGoogle Scholar
- IERS (2011) Proposed IERS local tie report layout, http://www.iers.org/nn_11306/IERS/EN/Organization/WorkingGroups/SiteSurvey/documents.html (24.1.2011)
- ITRF (2011) Co-location survey: online reports, ITRF web site: http://itrf.ensg.ign.fr/local_surveys.php (24.1.2011)
- Jokela J, Häkli P, Uusitalo J, Piironen J, Poutanen M (2009) Control measurements between the geodetic observation sites at Metsähovi. In: Drewes H (ed) Geodetic reference frames. IAG symposium, Munich, 9–14 Oct 2006. Springer, Berlin, pp 101–106Google Scholar
- Kallio U, Poutanen M (2009) Can we really promise a mm-accuracy for the local ties on a geo-VLBI antenna. In: Proceedings of the IAG symposium geodesy for planet Earth, Buenos Aires, Aug 31–Sep 4, 2009, Manuscript no: OS1-Mo14Google Scholar
- Kallio U, Poutanen M (2010) Simulation of local tie accuracy on VLBI antennas. In: Behrend D, Baver K (eds) VLBI2010: from vision to reality, proceedings of the sixth IVS general meeting, Feb 7–13, 2010, Hobart. NASA/CP-2010-215864. pp 360–364Google Scholar
- Kallio U, Poutanen M (2012) Can we really promise a mm-accuracy for the local ties on a geo-VLBI antenna. In: Geodesy for Planet Earth. Proceedings of the 2009 IAG Symposium, Buenos Aires, Argentina, 31 August 31 - 4 September 2009. Eds. Kenyon, S; M. Pacino; U. Marti. International Association of Geodesy Symposia, Vol. 136. Springer Verlag. p. 35-42, DOI: 10.1007/978-3-642-20338-1_5Google Scholar
- Leick A (1995) GPS satellite surveying. Wiley, New York. ISBN 0-417-30626-6Google Scholar
- Lösler M, Hennes M (2008) An innovative mathematical solution for a time-efficient vs reference point determination. In: Measuring the changes, 2008. 4th IAG symposium on geodesy for geotechnical and structural engineering, Lisbon, May 12–15, 2008Google Scholar