The MK_HREF2022 quasi-geoid model is a height reference surface for North Macedonia, referred to the GRS80 ellipsoid. It was computed by the Agency for Real Estate Cadastre of the Republic of North Macedonia, in cooperation with the Norwegian Mapping Authority (Kartverket), and it is given in the form of a regular grid, with resolution of 0.01° × 0.01°, within the limits of 40.8° < latitude < 42.4° and 20.4° < longitude < 23.1°. The model is based on a set of relatively new gravity data measured in 2014 (along the high accuracy levelling lines and in the frame of the regional gravimetric survey), in total 2470 points in mean-tide system. Stokes/Molodensky equations and the Fast Fourier transform technique were applied in the calculations, with use of the global geopotential model EGM2008. The computed quasi-geoid surface was fitted to 77 high quality GNSS/levelling points, fairly distributed throughout the territory of the country. The resulting height reference surface allows the conversion between ellipsoidal heights (ETRS89, epoch 1989.0) and heights in the official national height system (NVT1, datum Trieste 1875.0, normal orthometric heights). The inner accuracy of the calculated quasi-geoid model is 4.0 cm, while the outer accuracy (based on 1035 control GNSS/levelling measurements along levelling lines) is up to 10 cm. MK_HREF2022 is the official quasi-geoid model for North Macedonia since November 28, 2025.

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).