Terrain mapper

Terrain mappers were a type of device that could be used to identify features of a planet's terrain. At some point between 0 ABY and 3 ABY, Corporal Purpruff of the Alliance to Restore the Republic's Special Forces brought a terrain mapper with her to the planet Hoth while scouting for a new location for Alliance headquarters. Using the mapper she located a subterranean cavern near her landing site and hiked to the nearest entrance.

Behind the scenes
Terrain mappers were first mentioned in the 2017 reference book Star Wars: The Rebel Files, which was written by Daniel Wallace.