text: Chapter 1
  1-175. Survivability operations enhance the ability to avoid or withstand hostile actions by altering the
  physical environment. They accomplish this through four tasks:
  * Constructing fighting positions.
  * Constructing protective positions.
  * Hardening facilities.
  * Employing camouflage and concealment.
  The first three tasks focus on providing cover, while the fourth task focuses on providing protection from
  observation and surveillance. These four tasks often have the added benefit of providing some degree of
  shelter or protection from the elements. All four tasks are often addressed in combination. For example,
  constructing fighting positions and protective positions usually also requires employing camouflage and
  concealment. Employing camouflage and concealment often accompanies activities to harden facilities.
  Air and Missile Defense
  1-176. Army air defense artillery forces provide low-to-high altitude air and missile defense (AMD), and
  contribute to situational understanding, airspace management, freedom of movement, freedom from aerial
  attack, and early warning. These capabilities deter or defeat enemy aerial threats, protect the friendly force
  and high-value assets, and enable the friendly force’s freedom to operate. Enemy air threats include but are
  not limited to rockets, missiles, unmanned aircraft, and manned rotary- and fixed-wing aircraft. Counterair
  is a mission at the theater level that integrates offensive and defensive operations to attain and maintain a
  desired degree of control of the air and protection by neutralizing or destroying enemy aircraft and missiles,
  both before and after launch (JP 3-01). Counterair, from the active air defense perspective is a joint
  responsibility and will vary based on assets available and priorities. The area air defense commander through
  the area air defense plan executes this mission for a theater and provides the required integration and close
  coordination between Army air defense artillery forces and other counterair forces. Short-range air defense
  (known as SHORAD) assets may be attached or in direct support of corps and divisions.
  1-177. Units employ both active and passive methods of air defense to include air defense artillery systems,
  direct fire weapons systems, and air guards. Active AMD are direct defensive actions taken to destroy,
  nullify, or reduce the effectiveness of hostile air and missile threats against friendly forces and assets. It
  includes the use of aircraft, air defense weapons, electromagnetic warfare, and other available weapons.
  Active missile defense requires early detection of missiles in flight to permit cueing, acquisition, tracking,
  classification, identification, and destruction as soon as possible after launch. Passive AMD are all measures,
  other than active air defenses, taken to minimize the effects of hostile air and missile threats against friendly
  forces and assets. All units conduct passive actions to reduce the effectiveness of the enemy air threat. These
  measures include camouflage, concealment, military deception, dispersion, reconstitution, redundancy,
  detection and warning systems, and the use of protective construction. Passive actions are a unit’s first line
  of defense and improve survivability by reducing the likelihood of being detected and targeted from the air
  and by mitigating the potential effects of air surveillance and attack. Passive missile defense measures include
  detecting air and missile launches, predicting impact points, providing threat identification, and
  disseminating early warning. It includes measures initiated to reduce vulnerability and to minimize the effect
  of damage caused by missile attack.
  1-178. Generally, the joint force uses both offensive and defensive counterair operations to dominate enemy
  airspace and prevent the launch of threats. Offensive counterair operations include the suppression of enemy
  air defenses. Defensive counterair operations defeat enemy air and missile threats attempting to penetrate or
  attack through friendly airspace. Units integrate joint forces to exploit the mutually beneficial effects of
  offensive and defensive actions to destroy, neutralize, or minimize air and missile threats.
  1-179. Units coordinate and clear air and missile defense fires on the ground and through the airspace to
  enable rapid and timely engagement of threats while preventing fratricide. However, the ground force
  executing the defense ensures that as much as possible of their defended asset list is in range of these air and
  missile defense systems. Units take both active and passive air defense measures to protect themselves from
  aerial attack.
  1-180. A ground force’s organic weapons are its primary defense against short-range air threats. Units
  weigh the air threat with their ability to mitigate the threat when considering options for operations. Units