text: Fire Support Coordination Measures
  * Cell. GARS cells divide the surface of the earth into 30-minute by 30-minute cells (approximately
  55-kilometers (km) by 55 km).
  * Quadrant. Each 30-minute cell is divided into four 15-minute by 15-minute quadrants
  (approximately 28 km by 28 km).
  * Keypad. Each 15-minute quadrant is divided into nine 5-minute by 5-minute areas (approximately
  9 km by 9 km).
  * As GARS cells move away from the equator GARS cells get smaller.
  Figure B-5. Kill box graphic example
  AIRSPACE COORDINATION AREA
  B-27. Airspace coordination area is a three-dimensional block of airspace in a target area, established by the
  appropriate commander, in which friendly aircraft are reasonably safe from friendly surface fires. (JP 3-09.3).