text: Field Artillery Operations
  for each mission; the methods and techniques used to convert target information into the appropriate fire
  commands (TC 3-09.81). A fire direction center is that element of a command post, consisting of gunnery
  and communications personnel and equipment, by means of which the commander exercises fire direction
  and/or fire control (JP 3-09.3). The FDC receives target intelligence and requests for fire and translates them
  into appropriate fire direction.
  4-77. The FDC provides timely and effective tactical and technical fire control in support of current
  operations. Fire control is all operations connected with the planning, preparation, and actual application of
  fire on a target (TC 3-09.81). The FDC is the control center for the gunnery team. The FDC personnel receive
  calls for fire through the AFATDS, or by voice. The FDC will then process that information by using tactical
  and technical fire direction procedures.
  TACTICAL FIRE DIRECTION
  4-78. Tactical fire direction is primarily performed at the FA BN FDC. Tactical fire direction includes
  processing calls for fire and determining appropriate method of fire, ammunition type and quantity, unit(s)
  to fire, and time of attack. The fire direction officer's decision on how to engage the target is concisely stated
  as a fire order.
  4-79. A fire order is the fire direction officer's decision on what unit(s) will fire and how much and what
  type of ammunition will be fired. It is based on the fire direction officer's analysis of the target. The objectives
  of tactical fire direction include:
  * Providing continuous, accurate, and responsive fires in all conditions.
  * Maintaining the flexibility to engage various target types over wide frontages.
  * Massing the fires of available units.
  * Engaging a number and variety of targets simultaneously.
  TECHNICAL FIRE DIRECTION
  4-80. Technical fire direction is the process of converting weapon and ammunition characteristics (such as
  muzzle velocity, propellant temperature, and projectile weight), weapon and target locations, and MET
  information into firing data. Firing data is all data necessary for firing a weapon at a given target. FA firing
  data are determined by use of various firing tables and equipment. These tables contain the fire control
  information under standard conditions and data correcting for nonstandard conditions. Whether this process
  is done through an automated system or manually, the process is the same.
  4-81. Firing data provided to both cannon and MLRS units includes the number and type of munitions/shell,
  fuze setting and aim point(s), allowing the platform to compute its own firing data (deflection and quadrant
  elevation). Deflection is the setting on the weapon sight to place the line of fire in the desired direction. The
  azimuth of fire is the direction, expressed in mils, that a firing unit is laid (oriented) on when it occupies a
  position (ATP 3-09.50). Cannon units are usually also provided the charge and type of fuze, although this
  too can be calculated at the firing platform. For firing units without an on-board technical computation
  capability, or operating in a degraded mode, the FDC transmits firing data to the firing unit as fire commands.
  4-82. Fire commands are commands used by the FDC to give firing units all the information needed to
  conduct a fire mission. Initial fire commands include all elements needed for orienting, loading, and firing
  the weapon. Subsequent fire commands include only those elements that have changed from the previous
  commands, except quadrant elevation. Quadrant elevation is announced in every set of fire commands and
  allows the firing unit to fire in a weapons release status. For more information on fire commands see ATP 3-
  09.50. The surface-to-surface attack by FA depends on a number of factors including:
  * Meeting the five requirements of accurate predicted fire.
  * Identifying an appropriate target (TA process).
  * Initiating a call for fire into the FS system (the fire request).
  * Analyzing the fire mission to determine the proper method of attack.
  * Conducting clearance of fires (which includes coordinating airspace).
  * Transmitting the call for fire to the selected FDC(s) or firing element(s).