Modern GPS receivers have a grid implemented in their software by which they obtain, from the current position, the height of the geoid (e.g. the EGM-96 geoid) over the World Geodetic System (WGS) ellipsoid.
GPS receivers win amarăd ilan griyaj ehan software tan s karrăšan ɣur edag wan ahan iddikud n izuk n geoid (almital EGM-96 Geoid) fal World Geodetic System (GWS) ellipsoid