RSAA Colloquia / Seminars / Feast-of-Facts: Thursday, 17 November 2016, 11:00-12:00; Duffield Lecture Theatre

Lucia Plank

"Millimetre geodesy and the potential of VLBI satellite tracking"

In geodesy - the science of measuring the Earth - we are interested in the shape, the rotational behaviour and the gravitational field of our planet. Combining measurements to satellites using positioning and laser techniques with very long interferometry observations (VLBI) of extra-galactic radio sources, nowadays accuracies at the centimetre to millimetre scale are achievable. At the University of Tasmania we operate the Australian-wide AuScope VLBI array. Striving for the new way of remote operations as well as for improved observations, we can now report on significantly improved global and continental results. With increasing accuracies, understanding systematic errors between the measurement techniques becomes more and more important. One way to address this issue is a space tie satellite. This is the idea of a satellite carrying components from all techniques, namely a GPS receiver, an SLR (laser ranging) reflector and a VLBI transmitter. In this talk I will introduce the motivation for and the concept of a space tie, present current research on VLBI satellite tracking and review ongoing and future satellite mission proposals in this area.