trig point
noun /ˈtrɪɡ pɔɪnt/
/ˈtrɪɡ pɔɪnt/
(also triangulation point)
(specialist)- a position on a high place used as a reference point, especially by people who make and use maps. It is usually marked on the ground by a short stone pillar.
（地图制作和使用者设的）三角点 词源mid 19th cent.: abbreviation of trigonometrical point.