Combination of gravity datasets for geoid computation in New Zealand
20/09/2016 | 17:00 | Session 3: Local/regional geoid determination methods and models
Author(s): Rachelle Winefield and Euan Smith
Rachelle Winefield and Euan Smith
Before computing a gravimetric geoid disparate gravity datasets need to be combined into a single grid. Each gravity observation technique has different parameters and measures different parts of the gravity spectrum. This means that no one gravity dataset is able to fully model the gravity field at the scale necessary for geoid computation.
A case study from Canterbury, New Zealand, is used to evaluate different combination methods with the objective of determining an optimal grid of gravity anomalies for geoid modelling. An assessment is made of three integration methods: natural neighbour, ordinary kriging and least squares collocation. The resulting product is a grid of Bouguer anomalies, which combines satellite altimetry, terrestrial, ship-borne, airborne, and satellite gravimetry using least squares collocation.