Australia-Germany joint research cooperation to measure vertical deflections across Perth

Perth vertical deformation

The Department has received modest funding to bring in a German astrogeodetic observing system (QDaedalus) to measure a profile of vertical deflections across the Perth Basin.

Vertical deflections are the angular difference between the ellipsoidal normal and direction of the Earth’s gravity vector.  Perth exhibits one of the steepest gravity gradients on the planet, so vertical deflections can reach a minute of arc, thus presenting a challenging test of the instrument.

QDaedalus works by taking digital photographs of the night sky and uses a star almanac to determine astronomical latitude and longitude.  These are compared to geodetic latitude and longitude from a GPS receiver to determine the vertical deflections at each point along the profile.

These field observations will be used to validate the vertical deflections computed from AUSGeoid2020.  This will be first deployment of a high accuracy (0.2 arc second) astronomical camera along a geodetic traverse in Australia and even the Southern Hemisphere.

The project involves, from Curtin, Professor Will Featherstone, Dr Amy Parker and Todd Lyon, and from the Technical University of Munich, Dr Christian Hirt (a former employee of Curtin), Peter Schack and Markus Hauk.  It is funded by the Universities Australia consortium and DAAD, the German Academic Exchange Service.