The experimental xDEM2022 and its uses for geoid modelling at NGS

The U.S. National Geodetic Survey (NGS), an office of the National Oceanic and Atmospheric Administration (NOAA), is preparing for the release of a new vertical datum, the North American-Pacific Geopotential Datum of 2022 (NAPGD2022). This new datum will be based on a high degree spherical harmonic model of the Earth’s gravitational potential, and will yield a geoid undulation model (GEOID2022) to calculate orthometric heights from GNSS-derived ellipsoid heights.

A critical component of this new vertical datum is the terrain model that will be used for the geoid computation. Currently, an experimental version of this terrain model has been developed at NGS, the experimental Digital Elevation Model 2022 (xDEM2022). The xDEM2022 is composed of data from TanDEM-X, MERIT, and USGS 3DEP elevation data sets. Bathymetry and Ice thickness data has also been added to the latest version of the xDEM2022. An overview of the xDEM2022 will be presented with comparisons to other independent elevation datasets. Uses of this terrain model for geoid modelling at NGS will also be shown.