We present results from a new vertical deflection (VD) traverse observed in Perth, Western Australia, which is the first of its kind in the Southern Hemisphere. A digital astrogeodetic QDaedalus instrument was deployed to measure VDs with {\$}{\$}{\{}{\backslash}sim {\}}{\$}{\$}∼0.2{\$}{\$}''{\$}{\$}{\textasciiacutex}{\textasciiacutex}precision at 39 benchmarks with a {\$}{\$}{\{}{\{}{\backslash}sim {\}}{\}}1{\textasciitilde}{\backslash}hbox {\{}km{\}}{\$}{\$}∼1kmspacing. For the conversion of VDs to quasigeoid height differences, the method of astronomical--topographical levelling was applied, based on topographical information from the Shuttle Radar Topography Mission. The astronomical quasigeoid heights are in 20--30 mm (RMS) agreement with three independent gravimetric quasigeoid models, and the astrogeodetic VDs agree to 0.2--0.3{\$}{\$}''{\$}{\$}{\textasciiacutex}{\textasciiacutex}(north--south) and 0.6--0.9{\$}{\$}''{\$}{\$}{\textasciiacutex}{\textasciiacutex}(east--west) RMS. Tilt-like biases of {\$}{\$}{\{}{\backslash}sim {\}}1{\backslash},{\backslash},{\backslash}hbox {\{}mm{\}}{\$}{\$}∼1mmover {\$}{\$}{\{}{\backslash}sim {\}}1{\backslash},{\backslash},{\backslash}hbox {\{}km{\}}{\$}{\$}∼1kmare present for all quasigeoid models within {\$}{\$}{\{}{\backslash}sim {\}}20{\backslash},{\backslash},{\backslash}hbox {\{}km{\}}{\$}{\$}∼20kmof the coastline, suggesting inconsistencies in the coastal zone gravity data. The VD campaign in Perth was designed as a low-cost effort, possibly allowing replication in other Southern Hemisphere countries (e.g., Asia, Africa, South America and Antarctica), where VD data are particularly scarce.     «

We present results from a new vertical deflection (VD) traverse observed in Perth, Western Australia, which is the first of its kind in the Southern Hemisphere. A digital astrogeodetic QDaedalus instrument was deployed to measure VDs with {\$}{\$}{\{}{\backslash}sim {\}}{\$}{\$}∼0.2{\$}{\$}''{\$}{\$}{\textasciiacutex}{\textasciiacutex}precision at 39 benchmarks with a {\$}{\$}{\{}{\{}{\backslash}sim {\}}{\}}1{\textasciitilde}{\backslash}hbox {\{}km{\}}{\$}{\$}∼1kmspacing. For the conversion of V...     »