the act of reconnoitering.

Military . a search made for useful military information in the field, esp. 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

exploration , investigation , maneuvers , probe , recon , reconnoiter , review , scan , scrutiny , search , surveillance , survey , inspection , observation , scouting