An adaptive approach to optimise regional geoid undulation model for engineering applications

Geoid undulation model is typically used for the conversion between GNSS obtained ellipsoidal heights and their orthometric counterparts. In this study, an adaptive approach for optimizing regional geoid model based on global geoid model and local GNSS/leveling measurements is presented. A rigorous sequential least squares approach coupled with an adjustable criterion is used for identifying appropriate observables so that an optimized model that fulfills a predefined quality level can be automatically produced. It has been demonstrated that a city scale geoid undulation model with a quality level around ± 14 can be obtained by applying the proposed approach.