The Department of Transportation (DOT) and the Department ofDefense (DOD) today announced an agreement assuring civil usersof the satellite-based Global Positioning System (GPS) theavailability of a second frequency. A second frequency isessential for critical civilian uses of GPS. The White HouseCommission on Aviation Safety and Security, chaired by VicePresident Al Gore, called for the establishment of a second civilfrequency as part of a broader program to maintain U.S.leadership in aviation and satellite technology.

DOD agreed to assure civil users uninterrupted access to aportion of its military signal, known as the “carrier phase.”The uninterrupted access to L2 carrier phase for civilian useswill be reflected in the upcoming publication of the FederalRadionavigation Plan, jointly published by both departments.

Guaranteed availability of the L2 carrier phase will supportthe accelerated implementation of the Federal AviationAdministration’s (FAA) Wide Area Augmentation System (WAAS).WAAS is the centerpiece of FAA’s transition to a satellite basedair traffic control system. WAAS enhances the capabilities ofGPS signals by providing the accuracy, integrity, and reliabilityneeded to allow the system to be used by civilian pilots as aprimary means of navigation.

In addition, the DOT and DOD agreed to develop a plan forproviding a second frequency with course acquisition code andnavigation message for civil use. This will enhance worldwideGPS capability and allow each department to most effectively meetits responsibilities as laid out in the President’s GPS Policyissued in 1996. The addition of a second civil frequency willresult in an upgrading of the next generation satellites, knownas the Block IIF. The detailed plan for providing this codedsecond civil frequency will be announced within one year.

Dr. Paul Kaminski, Under Secretary of Defense forAcquisition and Technology, and Frank Kruesi, Assistant Secretaryfor Transportation Policy, met on February 22 to review thefrequencies specified in the Block IIF contract for possible useas the second civil frequency, referred to as L5. Although noneof the candidate frequencies was considered mutually acceptableto all federal agencies with an interest in GPS, DOT and DODreaffirmed their commitment to providing the second codedfrequency for civil use.

As a first step, DOD’s GPS Joint Program Office will requesta proposal from Boeing North American, the Block IIF contractor,for an alternative design for providing the second civilfrequency. Also, the DOD intends to investigate increasing therobustness of GPS for military use by supplementing the currentsystem with an enhanced military capability at a yet to bedetermined frequency.

These planned changes reflect the commitment in thePresident’s GPS Policy that the U.S. will provide the mostcapable and reliable satellite navigation system for use by allthe nations of the world well into the next century.

The DOT and DOD also announced the signing of the charterfor the Interagency GPS Executive Board (IGEB). The charter wassigned by Secretary of Defense William Cohen and Secretary ofTransportation Federico Pena before he left office. This board,established by the President’s GPS Policy, will provideinteragency management of the GPS and U.S. augmentations to theGPS, and policy guidance for U.S. efforts to assure globalacceptance of GPS technology.