The geoid for Costa Rica GCR-RSH-2020 (Geoide-Costarricense-Regional Calculado con el Método de Stokes-Helmert) is a 1 arc minute grid computed from terrestrial, marine and satellite gravity data. It is remarkable the comprehensive data cleaning and the use of new terrestrial gravity values which were not included in any other geoid determinations. The GECO global geopotential model was used for the data gap filling. The GCR-RSH-2020 computation was based on the Stokes-Helmert approach developed by the University of New Brunswick, using GOCO05s as background global geopotential model. The resulting geoid is distributed in the WGS84 system (note that between WGS84 and WRS80, there is a shift of approximately 93 cm for Costa Rica). The GCR-RSH-2020 accuracy was assessed by comparing it with GNSS/levelling values on 25 selected benchmarks of the Costa Rica vertical reference system, showing differences with a standard deviation of 0.207 m.

The geoid model is provided in ISG format 2.0 (ISG Format Specifications), while the file in its original data format is available at the model ISG webpage.

The International Service for the Geoid (ISG) was founded in 1992 (as International Geoid Service - IGeS) and it is now an official service of the International Association of Geodesy (IAG), under the umbrella of the International Gravity Field Service (IGFS). The main activities of ISG consist in collecting, analysing and redistributing local and regional geoid models, as well as organizing international schools on the geoid determination (Reguzzoni et al., 2021).