text: Chapter 2
  protection. Integrated active AMD measures are established and executed concurrently with attack operations
  and passive defenses.
  EXECUTION
  2-27. Ground-based or aerial sensors, or combinations of both when available, are employed to perform
  surveillance of the airspace and provide focused early warning to at-risk forces. The sensors provide
  engagement authorities the time to make engagement decisions that deny threat platforms the ability to see
  or impact the defended assets.
  2-28. These engagement authorities function as a vertically and horizontally integrated kill chain. The kill
  chain is the successive linkage of commanders who can authorize engagements of air and missile
  threats. Engagement decisions are made by the designated engagement authority in the kill chain, providing
  operational control of and, ultimately, directions to the shooter. Integrated sensors, shooters, and C2 networks
  will allow for greatly increased engagement options. As such, engagement authorization must be delegated
  to the lowest level possible.
  2-29. Proactive engagements are conducted in accordance with theater-level rules of engagement (ROE) and
  complementary directives. Engagements are conducted by the best shooter, that weapon system that can best
  deliver the appropriate effects to achieve maximum attrition at the right time and place, and as far forward as
  possible, to ensure keep-out ranges and keep-out altitudes. Keep-out range is the horizontal distance from
  a defended asset at which a successful engagement denies an adversary's desired weapons effects
  against the defended asset. A keep-out range is a key defense design consideration for cruise missiles. It
  also allows AMD systems to counter enemy aerial surveillance and reconnaissance platforms beyond the
  range at which they can surveil an asset and beyond the engagement capability of a defending AMD system,
  contributing to the overall ability of friendly forces to see first. Keep-out altitude is the vertical distance
  above a defended asset at which a successful engagement denies an adversary's desired weapons effects
  against the defended asset. A keep-out altitude is a major design consideration for ballistic missiles.
  Shooters may use shoot-new target-shoot, shoot-look-shoot, salvo, or ripple methods of fire, depending upon
  the type of system. The method of fire may be stipulated in operation plans, directed by the kill chain, or
  influenced by the situation. Coordination is effected by the AMD C2 elements to ensure the threats are
  overmatched by the AMD weapons, facilitating their destruction while simultaneously mitigating the
  potential for fratricide of friendly and neutral aircraft.
  2-30. Combined arms for air defense constitutes another element of Army AMD that can provide vital
  protection from air threats and contribute to the freedom of maneuver for friendly forces. (See chapter 11 for
  a fuller discussion of combined arms contributions to AMD). Maneuver forces can effectively engage
  hovering or slow-moving helicopters within their weapon systems' ranges. Stinger teams organic to maneuver
  formations further enhance this capability. The ADAM cell (see chapter 10) in the maneuver brigade links
  the maneuver forces to the kill chain to implement appropriate ROEs. Intelligence enables cyber and
  electronic warfare elements to electronically attack air targets. Intelligence elements can also provide or assist
  in the surveillance, identification, and classification of air targets, facilitating early warning.
  ENGAGEMENT SEQUENCE
  2-31. The engagement sequence is the successive actions taken by all of the services’ air and missile
  defense systems in the engagement of aerial threats. Terms in the sequence differ by service but capture
  similar actions. The ADA engagement sequence terms are surveil, detect, track/identify, threat evaluation
  and weapons assignment, engage, and assess.
  * Surveil. Surveil is the systematic observation of airspace by electronic, visual, or other means,
  primarily for the purpose of identifying and determining the movements of friendly and enemy
  aircraft and missiles in the airspace.
  * Detect. Detect in tactical operations is the perception of an object of possible military interest but
  unconfirmed by recognition. For ADA units, detect is the acquisition of an aerial object of possible
  military interest by sensor systems.
  * Track/identify. Track is the process of displaying or recording the successive positions of a moving
  object. Identification is the process of determining the friendly or hostile character of an unknown