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GPS APPLICATIONS AND REQUIREMENTS 25 Table 2-3 Military Land Applications and Requirementsa Application Accuracy Resistance to RF Interference Chemical Warfare 100.0 m CEP High Engineer Mine Neutralization 100.0 m CEP High Mine Dispensing & Gap Crossing 50.0m CEP High Field Artillery MLRS 20.0 m CEP High Howitzer 175 m CEP High Mortars 50.0 m CEP High Fist-V & Forward Observer 30.0 m CEP High Artillery and Mortar Radar 10.0 m CEP High Infantry & Armorb 100.0 m CEP High Missile Munitions 93.0 m CEP High Signal 15.0 m CEP High Special Operations Forces 30.0 m CEP High Intelligence Electronic Warfare 20.0 m CEP High Ordnance 84.0 m CEP High Air Defense Artillery Patriot 10.0 m CEP High Hawk 40.0 m CEP High a. Availability, integrity, and continuity of service requirements are not specified for military land transportation applications. b. The Infantry & Armor category also includes transportation, soldier support, military police, and quartermaster. Anti-Jam and Anti-Spoof Capability Although the "Resistance to RF Interference" column in Tables 2-1 through 2-3 does not include quantitative values, a high level of resistance to RF interference is a critical requirement for most military applications.10 For the military, the primary interference concerns are deliberate jamming and spoofing by an adversary or by our own forces. In future conflicts, a potential enemy also will be utilizing the capabilities of GPS and DGPS against U.S. and allied military forces. In order to deny this use, friendly forces must have the ability to eliminate an adversary's use of GPS signals without impacting the effectiveness of their own user equipment. This dictates that military GPS receivers also must be capable of continued operation in an environment populated with both U.S. and enemy jammers. Therefore, GPS-based navigation systems used on aircraft, ships, land vehicles, and precision-guided munitions must possess one or more of the following capabilities: 10 Quantifiable values for resistance to RF interference are given in decibels (dB), and relate to the ratio of jammer power to signal power (J/S). These values are very specific to a given mission and operational environment, making a generic J/S requirement for a given application difficult to determine.