ⵉⵜⵜⵓⵙⵡⵓⵔⵉ ⴷ ⴰⵙⴰⵜⵉ ⴰⵏⵙⴰⵖⵓⵍ ⵉ ⵜⴳⵓⵔⵉ ⵏ GPS ⵉⴼⵉⵎⵉⵔⵉⴷ (ⵉⵙⴰⵜⵓⵢⵏ) ⵙⴳ 23 ⵢⴰⵏⴰⵢⵔ 1987.