U

reconnaissance

noun

the act of reconnoitering.
Military. a search made for useful military information in the field, especially by examining the ground.
Surveying, Civil Engineering. a general examination or survey of a region, usually followed by a detailed survey.
Geology. an examination or survey of the general geological characteristics of a region.

noun

the act of reconnoitring
the process of obtaining information about the position, activities, resources, etc, of an enemy or potential enemy
a preliminary inspection of an area of land before an engineering survey is made

1810, from French reconnaissance “act of surveying,” literally “recognition,” from Old French reconoissance “recognition, acknowledgement” (see recognizance).