Terrestrial monitoring of a radio telescope reference point using comprehensive uncertainty budgeting – Investigations during CONT14 at the Onsala Space Observatory
Journal article, 2016

During the 15-day-long global very long baseline interferometry campaign CONT14, a terrestrial monitoring campaign was carried out at the Onsala Space Observatory. The goal of these efforts was to monitor the reference point of the Onsala 20 m radio telescope during normal telescope operations. Parts of the local site network as well as a number of reflectors that were mounted on the 20 m radio telescope were observed in an automated and continual way using the in-house-developed software package HEIMDALL. The analysis of the observed data was performed using a new concept for a coordinate-based network adjustment to allow the full adjustment process in a true Cartesian global reference frame. The Akaike Information Criterion was used to select the preferable functional model for the network adjustment. The comprehensive stochastic model of this network adjustment process considers over 25 parameters, and, to describe the persistence of the observations performed during the monitoring with a very high measurement frequency, includes also time-dependent covariances. In total 15 individual solutions for the radio telescope reference point were derived, based on monitoring observations during the normal operation of the radio telescope. Since the radio telescope was moving continually, the influence of timing errors was studied and considered in the adjustment process. Finally, recursive filter techniques were introduced to combine the 15 individual solutions. Accuracies at the sub-millimeter level could be achieved for the radio telescope reference point. Thus, the presented monitoring concept fulfills the requirement proposed by the global geodetic observing system.

Reference point determination

Akaike Information Criterion

Radio telescope

Bundle adjustment


Least-squares analysis




Michael Lösler

Goethe University Frankfurt

Rüdiger Haas

Chalmers, Earth and Space Sciences, Space Geodesy and Geodynamics

Cornelia Eschelbach

Goethe University Frankfurt

Journal of Geodesy

0949-7714 (ISSN) 1432-1394 (eISSN)

Vol. 90 5 467-486

Driving Forces

Sustainable development

Innovation and entrepreneurship


Basic sciences


Onsala Space Observatory

Subject Categories

Earth and Related Environmental Sciences



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