ⵉⴷⵖⴰⵔ ⵉⵜⵜⴰⵎⵣⵏ ⴳⵯ GPS ⵓⵊⴷⵉⴷ ⵖⵓⵔⵙⵏ ⵜⴰⵔⴰⵜⵙⴰ ⴰⴳⵯⵏⵙⵓ ⵏⴰⵙ ⵜⴰⵎⵥⵏ, ⵙⴳⵯ ⵓⴷⵖⴰⵔ ⵏⴰⴳⵯ ⵍⵍⴰⵏ, ⵜⵉⵊⴳⵯⵍⵜ ⵏ ⵊⵉⵢⵓⴷ (ⵣⵄⵏⴷ EGM-96 ⵊⵉⵢⵓⴷ) ⴳⵯ ⵓⵏⴳⵯⵔⴰⵡ ⵏⵉⴷ ⵊⵉⵢⵓⴷ ⵏⵓⵎⴰⴹⴰⵏ (WGS).