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On January 29 of this year, the United States National Geodetic Survey (NGS) published the latest experimental geoid model called xGEOID20, along with a new tool for gravity interpolation.
Similarly, you have updated the dynamic model of the geoid in the form of the xDGEOID20. This will be the last experimental geoid model until 2022.
The xDGEOID20 is produced by the NGS within the Geoid Monitoring Service (GeMS), and is part of the new North-American-Pacific Geopotential Datum 2022 (NAPGD2022). Therefore, users will have just a few more years to understand the differences between the hybrid geoid model used today to estimate orthometric heights derived from GNSS satellite positioning systems, and the gravimetric geoid model that will be used to estimate. the GNSS-derived orthometric heights in the NAPGD2022 datum.

The NGS also announced a new gravity determination tool, called “The Experimental Gravity Model 2020 (xGRAV20)”. The xGRAV20 is designed to provide a full gravity field value and digital elevation model height at a specific location. This model will be of great importance for users who calculate orthometric heights derived from leveling, consistent with the NAPGD2022.

It is important to note that the xGEOIDnn models provide a preliminary but increasingly accurate view of the changes expected by the upcoming NAPGD2022. Furthermore, the xGEOID20 geoid model is the first combination of the geoid models calculated by scientists from the NGS and those from the Canadian Geodetic Survey (CGS). A unique element of the xGEOID20 is that the differences between model A and B are due to the contribution of GRAV-D airborne gravity and differences in methodology.
The NGS has published annual experimental geoid models (xGEOID) since 2014. Each of these experimental geoids demonstrate the improvements provided by the addition of airborne gravity data (GRAV-D data) and by refining the calculation methods. geoid.
For more details on the new experimental geoid model and the interactive interpolation tool, please go to the following link:


Original article in English published on February 3, 2021 in the digital magazine GPS World with the title “NGS releases annual experimental geoid models and gravity interpolation tools” in its digital version, and translated into Spanish with certain modifications by Ing. Alexander Gonzalez , MSc.