Surface Based Modelling of Ground Motion Areas in Lower Saxony

Abstract

Systematic investigations have shown subsidence in almost 30% of the land area in Lower Saxony. It is essential to model these variations of the Earth surface especially to update the spatial reference system. Since the geodetic observations result in discrete points, it is necessary to mathematically model these measurements to have a continues surface. This enables the user to do predictions at any position. This is challenging especially because these types of measurements usually result in non-uniformly distributed data. There are different approaches to deal with this problem, here the stochastic method of Kriging and the deterministic method of Multilevel B-Splines are implemented to model ground motion. This paper investigates the ground motion of specific areas in Lower Saxony through the cooperation of Landesamt für Geoinformation und Landesvermessung Niedersachsen (LGLN) and Geodetic Institute of Hannover. For this investigation, a time series of measurements from leveling, Global Navigation Satellite System (GNSS) observations and height changes that are acquired by Persistent Scatterer Interferometry (PSI) technique are taken into consideration. Evaluation of the results show not only good performance and promising results from both the approaches, but also compatibility between the approximated surface from both of them.