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News Release


Release No: 095-97
February 27, 1997


The Department of Transportation (DOT) and the Department of Defense (DOD) today announced an agreement assuring civil users of the satellite-based Global Positioning System (GPS) the availability of a second frequency. A second frequency is essential for critical civilian uses of GPS. The White House Commission on Aviation Safety and Security, chaired by Vice President Al Gore, called for the establishment of a second civil frequency 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 a portion of its military signal, known as the "carrier phase." The uninterrupted access to L2 carrier phase for civilian uses will be reflected in the upcoming publication of the Federal Radionavigation Plan, jointly published by both departments.

Guaranteed availability of the L2 carrier phase will support the accelerated implementation of the Federal Aviation Administration's (FAA) Wide Area Augmentation System (WAAS). WAAS is the centerpiece of FAA's transition to a satellite based air traffic control system. WAAS enhances the capabilities of GPS signals by providing the accuracy, integrity, and reliability needed to allow the system to be used by civilian pilots as a primary means of navigation.

In addition, the DOT and DOD agreed to develop a plan for providing a second frequency with course acquisition code and navigation message for civil use. This will enhance worldwide GPS capability and allow each department to most effectively meet its responsibilities as laid out in the President's GPS Policy issued in 1996. The addition of a second civil frequency will result in an upgrading of the next generation satellites, known as the Block IIF. The detailed plan for providing this coded second civil frequency will be announced within one year.

Dr. Paul Kaminski, Under Secretary of Defense for Acquisition and Technology, and Frank Kruesi, Assistant Secretary for Transportation Policy, met on February 22 to review the frequencies specified in the Block IIF contract for possible use as the second civil frequency, referred to as L5. Although none of the candidate frequencies was considered mutually acceptable to all federal agencies with an interest in GPS, DOT and DOD reaffirmed their commitment to providing the second coded frequency for civil use.

As a first step, DOD's GPS Joint Program Office will request a proposal from Boeing North American, the Block IIF contractor, for an alternative design for providing the second civil frequency. Also, the DOD intends to investigate increasing the robustness of GPS for military use by supplementing the current system with an enhanced military capability at a yet to be determined frequency.

These planned changes reflect the commitment in the President's GPS Policy that the U.S. will provide the most capable and reliable satellite navigation system for use by all the nations of the world well into the next century.

The DOT and DOD also announced the signing of the charter for the Interagency GPS Executive Board (IGEB). The charter was signed by Secretary of Defense William Cohen and Secretary of Transportation Federico Pena before he left office. This board, established by the President's GPS Policy, will provide interagency management of the GPS and U.S. augmentations to the GPS, and policy guidance for U.S. efforts to assure global acceptance of GPS technology.

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