The Global Positioning System: A Shared National Asset (1995)
Chapter: Current and Future Applications and Requirements
to replace all other operational systems.3 The coalition military forces demonstrated the effective use of GPS for many of these proposed applications during the Persian Gulf War, despite the fact that the GPS constellation consisted of only 16 satellites at the time. This limited three-dimensional coverage of the Persian Gulf region to 18 hours per day. Another limiting factor was the small number of P-code military receivers in the DOD inventory at the time of the conflict. This prompted a National Command Authority decision to turn SA to zero during the war and led to the DOD's purchase of thousands of civilian GPS receivers, which became known as "sluggers".4 In addition to this official procurement, many units and individuals deployed to the Persian Gulf ordered their own GPS receivers directly from vendors and manufacturers.5
Current and Future Applications and Requirements
The most common use of GPS during the Persian Gulf War, and perhaps the most critical, was for land navigation. U.S. Army tanks and infantry relied heavily on GPS to avoid getting lost during movements to various destinations in the featureless desert. GPS also was used by coalition forces for en route navigation by aircraft, helicopter search and rescue, marine navigation, and even munitions guidance in the case of the U.S. Navy's Standoff Land Attack Missile (SLAM).6
The use of GPS for precision-guided munitions such as the SLAM will increase in the future. The U.S. military currently has, or is developing, eight additional types of precision land attack weapons that utilize GPS integrated with inertial navigation systems for mid-course guidance.7 Another important GPS application under consideration is the
