1. Professor of Geodesy, School of Earth and Planetary Sciences, Curtin Univ. of Technology, GPO Box U1987, Perth, WA 6845, Australia (corresponding author). ORCID: .
2. Doctoral Student, School of Earth and Planetary Sciences, Curtin Univ. of Technology, GPO Box U1987, Perth, WA 6845, Australia. ORCID: .
3. Geodetic Gravity Officer, National Geodesy Section, Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia. ORCID: .