text: Reconnaissance and Security
  Figure 5-4. Reconnaissance-push, example
  5-58. The chief reason for preferring one method tothe other is the time available or confidence in the IPB.
  The time required to develop a COAcan give the enemy enough time to recover and prepare so that taking
  an objective may cause higher casualties than necessary. Commanders balance the time needed to develop a
  COA with the need to act rapidly and decisively on the battlefield. There is no available model that a
  commander can use to determine how much enough is;that determination is part of the art of command (the
  creative and skillful exercise of authority through decision-makingand leadership).
  SURVEILLANCE
  5-59. Surveillance is the systematic observation of aerospace, cyberspace, surface, or subsurface areas,
  places, persons, or things by visual, aural, electronic, photographic, or other means (JP 3-0). Surveillance
  may be a stand-alone mission or part of a reconnaissance mission (particularly area reconnaissance). Both
  reconnaissance and surveillance produce raw data and information, some of which may be combat
  information that meets one or more of the CCIRs or intelligence requirements. A key difference between
  surveillance missions and reconnaissance is that surveillance is tiered and layered with technical assets and
  it is passive and continuous. Reconnaissance is active in the collection of information (such as maneuver)
  and usually includes human participation.