What type of surveillance is characterized by the intent for the target to know they are being observed?

The type of surveillance characterized by the intent for the target to know they are being observed is open surveillance. This approach typically involves the visible presence of law enforcement or security personnel, making it clear to the subject that they are being watched. Open surveillance can serve multiple purposes, such as deterrence of criminal behavior or monitoring a subject's actions without the need for secrecy.

In contrast, close surveillance usually refers to closely following an individual while remaining discreet, while covert surveillance aims to observe without the subject’s awareness at all, maintaining complete secrecy about the observation. Undercover surveillance involves an operative disguising their identity to gather intelligence or evidence without the target's knowledge. Each of these other methods operates under the premise that the subject is unaware of being surveilled, which distinguishes open surveillance as the only technique where the fact of observation is made apparent.