text: Chapter 4
  involves observing an area to collect information and observing the threat and local population in an NAI or
  a TAI. Surveillance may be a stand-alone mission or part of a reconnaissance mission (particularly area
  reconnaissance). Elements conducting surveillance must maximize assets, maintain continuous surveillance
  on all NAIs and TAIs, and report all information accurately. A variety of assets (ground, air, sea, and space),
  means (Soldiers and systems), and mediums (through the electromagnetic spectrum) can perform
  surveillance tasks. Effective surveillance—
  * Maintains continuous observations of all assigned NAIs and TAIs.
  * Provides early warning.
  * Detects, tracks, and assesses key targets.
  * Provides mixed, redundant, and overlapping coverage.
  4-32. Cavalry units conduct surveillance as a “task” while conducting reconnaissance operations.
  Surveillance is similar to reconnaissance, because they both include observation and reporting and involve
  detection, location, tracking, and identification of entities in an assigned area, gaining environmental data.
  Surveillance is distinct from reconnaissance in that surveillance is tiered and layered with technical
  capabilities and systems that collect information. Surveillance is passive and continuous; reconnaissance is
  active in the collection of information (such as maneuver) and usually includes human participation and
  fighting for information. Surveillance and reconnaissance complement each other by cueing the commitment
  of collection capabilities against locations or specially targeted enemy units.
  SECTION II – RECONNAISSANCE TYPES
  4-33. The five types of reconnaissance operations are zone, area, route, reconnaissance in force, and special
  reconnaissance. All types of reconnaissance, driven by the fundamentals of reconnaissance, answer PIRs that
  allow the commander and staff to understand and visualize the environment, develop the situation, create
  options, identify opportunities, and make decisions.
  4-34. Zone reconnaissance allows intelligence development on threat, terrain, infrastructure, and society
  within a specified zone of operations. Zone reconnaissance operations are generally large, deliberate, and
  thorough efforts designed to gain a significant amount of information. Area reconnaissance focuses
  reconnaissance efforts within a smaller geographic area than zone reconnaissance but requires collecting the
  same information as for zone reconnaissance, as well as information about dominant terrain outside the
  specified area from which the threat can still influence friendly operations. Route reconnaissance is a directed
  operation to obtain detailed information of a specific route and the influential terrain along the route.
  Reconnaissance in force is an operation to determine the enemy’s strength, disposition, and reactions in a
  specified area, conducted by battalion-sized TFs or larger elements. Special reconnaissance is an operation
  conducted by SOF in hostile, denied, or diplomatically and politically sensitive environments to collect or
  verify information of strategic or operational significance. Special reconnaissance capabilities and assets are
  not usually available to conventional forces.
  Note. When the Cavalry unit receives a reconnaissance mission from higher headquarters, the unit
  may perform a combination of reconnaissance types to answer the higher commander’s
  information requirements. For example, if the Cavalry squadron’s mission is to conduct zone
  reconnaissance, their subordinate units may conduct a combination of zone, area, or route
  reconnaissance missions inside the assigned squadron zone of operations.