The ETH-QM21 model is a gravimetric quasigeoid of 2'x2' spatial resolution developed over Ethiopia. This solution has been derived from the ETH-GM21 gravimetric geoid model by using the ETH-GQS geoid-to-quasigeoid separation surface over Ethiopia (see Dataset Description). Considering the rough topography of Ethiopia, the ETH-QM21 would be beneficial for normal height measurements. The ETH-QM21 model would be beneficial for normal height measurements, also considering the rough topography of Ethiopia.

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).