A strategic independent VLBI network for Europe to accurately determine Earth Orientation Parameters needed for precision positioning and navigation on Earth and in space

摘要

Earth Orientation Parameters (EOP) are required to link the International Celestial Reference Frame (ICRF) to the International Terrestrial Reference Frame (ITRF). The ITRF is required for modern mapping (cadastral surveying, topographical, geological and hydrographical) and is used in all activities where precise positioning in a modern reference frame is required; this includes precise satellite orbit determination and high accuracy navigational requirements. These EOP cannot be modelled to high accuracy, due to the complicated and stochastic nature of global mass transport on Earth, and therefore must be measured using the space geodetic technique of Very Long Baseline Interferometry (VLBI). In a strategic sense, the USA, China, the Russian Federation and the European Union (EU) have recognised the need to develop independent Global Navigation Satellite Systems (GNSS) constellations, resulting in the GPS, Beidou, Glonass and Galileo constellations, respectively. Of these, only the EU does not have the landmass to enable VLBI networks with sufficiently long North-South and East-West baselines to allow EOP measurements with high accuracy. Here we report on our results to create a strategic EOP network for the EU, based on VLBI stations in Europe (Wettzell) and South Africa (HartRAO), and German owned stations in South America (Chile) and Antarctica (O’Higgins). The Vienna VLBI Software (VieVS) is used to analyse the strategic network. We find that these long baselines will provide independent EOP of sufficiently high accuracy. It is essential that the German VLBI station in South America, which has now moved from Chile to Argentina, be equipped with a modern VLBI antenna meeting Global Geodetic Observing System (GGOS) standards; this will ensure also providing the EU with capacity to maintain satellite orbits and be non-reliant on other superpowers for advanced navigational requirements.