Study of the Ecuadorian Vertical Reference System in the Vertical Datum Unification Context

Ecuador, like all the South American countries, currently does not have a single Vertical Reference System (VRS). Each country has the Vertical Datum (VD) associated with a level surface obtained from one or more tide gauges records. Moreover, these references were defined in different epochs. The relationship between the different Local Vertical Frames (LVFs) is conditioned, ideally, for the temporal variations of the ocean surface. The LVFs offset is a key element to achieving a Global VRS (GVRS), which allows the determination of physical heights and contribute to the monitoring of physical parameters of the Earth System. In this article, we present a study of the Ecuadorian VRS (EVRS) in terms of height type, consistency with Global Geopotencial Models (GGMs) and its relationship with a GVRS. In addition, the Residual Terrain Modeling (RTM) technique was explored to complement the high-frequency spectral information in GGMs; the used Digital Elevation Models (DEM) were the Global Multi-Resolution Topography (GMRT) and the ETOPO1 - Global Relief Model. An alternative approach based on the oceanographic model MSS CLS011 and the model GOCONS-TIM-R5 was used for the estimation of the Sea Surface Topography (SSTop) in the fundamental tide gauge in Ecuador.

Keywords:
Ecuadorian Vertical Reference System; Sea Surface Topography; Digital Height Models; Global Geopotencial Models