text: Chapter 3
  SPACE SITUATIONAL AWARENESS
  3-6. SSA is fundamental to conducting space operations. It integrates space-based surveillance, collection,
  and processing; environmental monitoring; status of U.S. and cooperative nations satellite systems; status of
  U.S. and multinational space readiness; and analysis of the space domain. SSA must incorporate
  understanding of the space capabilities and intent of those who pose a threat to Army space operations and
  capabilities. SSA includes physical, virtual, information, and human dimensions; and the factors, activities,
  and events of all entities conducting, or preparing to conduct space operations. Simply stated, SSA includes
  detection, characterization, and assessment of the capabilities and intent of our adversaries.
  3-7. SSA requires in-depth knowledge of the space domain, understanding of the OE, intelligence on all
  foreign space systems, correlation of effects to a cause, and proper distribution and sharing of SSA
  information. SSA supports these four key objectives.
  * Ensure space operations and spaceflight safety. SSA provides the infrastructure to ensure space
  operators understand the conditions which could adversely impact successful space operations
  and spaceflight safety, such as collision avoidance of on-orbit assets.
  * Implement international treaties and agreements. SSA is a means by which compliance can be
  verified and by which violations can be detected.
  * Protect space capabilities. The ability to monitor all space activity enables protection of space
  capabilities, helps deter others from initiating attacks against terrestrial and space capabilities, and
  assures allies of continuing support during peace, crisis, and conflict.
  * Protect military operations and national interests. SSA supports and enhances military operations.
  3-8. SSA operations are continuous to ensure the current and future locations of terrestrial and space
  systems are known with reliable accuracy. SSA is fundamental to unified land operations because it
  characterizes space capabilities and integrates information collection analysis which contribute to the Army’s
  ability to understand and react to enemy intent.
  3-9. Characterization of friendly assets is necessary to support friendly system anomaly resolution,
  establish baselines for evaluating enemy space object identification and surveillance capabilities, and
  supports indications and warning development.
  3-10. SSA provides the commander the ability to identify the space capabilities available and impacts to
  operations in the area of operations. It provides insight into enemy space capabilities and threats to U.S. space
  capabilities. Understanding enemy intent is critical to every operation. SSA operations are continually
  ongoing to ensure the current and future locations of all satellites are known. Friendly forces may be warned
  when enemy space-based information collection assets will be in position to view and record friendly force
  activities. SSA supports assured communications which are critical for friendly PNT, FFT, and SATCOM
  capabilities to assess unwanted intrusions, attacks, interference, or unintentional hazards. SSA safeguards
  targeting and fires assets from unintentional hazards such as radio frequency interference and other naturally
  occurring phenomenon.
  POSITIONING, NAVIGATION, AND TIMING
  3-11. The GPS is a constellation of Earth orbiting satellites and associated ground control stations
  providing timing data to military and civilian users all over the world. Public law and national policy
  mandates GPS is designated for both military and civilian use.
  3-12. The GPS system is operated by the Air Force. Each GPS satellite broadcasts a continuous timing
  signal so properly equipped users with direct line of sight access to the satellites can receive and use the
  signals simultaneously. When signals from at least four satellites are being received, a GPS receiver can
  calculate three-dimensional position. With the proper equipment users obtain the timing signal and can
  calculate current position and velocity. GPS is a passive system; therefore, a Soldier can receive and use the
  signal without emitting a signal that might compromise their location.
  3-13. GPS provides a continuous, precise, all-weather timing signal accurate to a few nanoseconds (ten-
  billionths of a second). This signal is used to support navigation services, including: