From quasars to geodesy: how astronomy can enable a new era in ultra-precise geodetic measurements


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Novel Techniques for the VLBI Global Observing System (NT-VGOS) is a consortium of the Finnish Geospatial Research Institute and Aalto University Metsähovi Radio Observatory funded by the Academy of Finland. The aim of the NT-VGOS is to bring together expertise from astronomy and geodesy to develop a new method to foster the ultra-precise Very Long Baseline Interferometry (VLBI) observations. Geodetic VLBI observations utilize extragalactic radio sources, quasars, as reference points when measuring Earth's shape and orientation in space. Quasars, however, are not point-like sources but their internal structure will degrade the accuracy of the observations and ultimately, accuracy of the final product, the global reference frame.

We will develop an automated method to measure and apply the actual structure of the radio source in future VLBI observations which will be a big leap towards the millimetre-accurate global geodetic reference frame. New levels of accuracy for global geodetic reference frames have far-reaching consequences in studies of the global change, ultra-precise positioning and real-time navigation.

The project reinforces and supports exploring the full capacity of new global geodetic observing network VGOS (VLBI Global Observing System) – a global infrastructure project in which Finland takes part. The new VGOS radio telescope has been built at Metsähovi Geodetic Research Station in 2018 and is currently going through the commissioning phase.

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Academy of Finland
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Aalto University Metsähovi Radio Observatory