Core · Unit · Rules

If one or more friendly Units with Surveyor are within 1” of a Zone with friendly Occupiers at the end of the Round, you may place one Mapping Token on that Zone. When Searching for an Objective, you may spend two Mapping Tokens on that Zone to find the Objective on a 2+. If you have no Friendly Units with Surveyor within 1” of a Zone at the end of any activation (yours or your opponent’s), remove all your Mapping Tokens from it.

Source: Dropzone Commander Rulebook 3.02 · 3.02 · p. 47 · unit-special-rules