U

reconnoiter

verb (used with object)

to inspect, observe, or survey (the enemy, the enemy’s strength or position, a region, etc.) in order to gain information for military purposes.
to examine or survey (a region, area, etc.) for engineering, geological, or other purposes.

verb (used without object)

to make a reconnaissance.

also reconnoitre, 1707, “make a survey,” from older French reconnoitre (Modern French reconnaître), from Old French reconoistre “to identify” (see recognize).