Improving New Zealand’s Geoid-Based Vertical Datum with Airborne Gravimetry

Abstract:

Land Information New Zealand (LINZ) is midway through a project to improve the accuracy of the quasigeoid-based New Zealand Vertical Datum 2009 to 3cm in developed areas. Much of the geoid accuracy improvement is expected to be attributed to the incorporation of recent airborne gravity data, re-analysis of existing terrestrial gravity observations and newer satellite gravity models. In this paper we outline the results of the recent airborne gravity collection campaigns (2013-14) over New Zealand and their contribution to an improved national geoid. The airborne data and the resultant geoid model are validated by comparisons with terrestrial gravity and GNSS-levelling data along two 35-50 km calibration lines. We also evaluate the potential of the resulting geoid to form the basis of the updated New Zealand Vertical Datum.