3.2.3 その他の情報
3.2.3.1 CGSIC Boasts Broad Agenda -FRP, WAAS, Galileo, Modernization
Attendees at the 34th meeting of the Civil GPS Service Interface Committee (CGSIC) held Sunday and Monday heard the traditionally wide-ranging discussion of GPS issues addressed by this forum for information exchange. Organized by the U.S. Department of Transportation and the U.S. Coast Guard, this year's meeting topics included the new civil GPS signals, radionavigation planning, Europe's proposed Galileo system, and GPS precise timing.
Heywood Shirer, a staff member in the Office of the Secretary of Transportation, Policy (OST/P), reported that the Federal Radionavigation Plan (FRP) is expected to be signed by the secretaries of transportation and defense and published within about a month. The primary issue holding up release of the key planning and policy document is the question of retention or phase-out of Loran-C. Originally planned to begin at the end of next year, the phase-out of the widely used terrestrial radionavigation system would be retained for an indeterminate amount of time to provide a back-up to GPS under a more recent proposal from OST/P. The forthcoming FRP (which will be designated as the 1999 version and the biennial publishing cycle moved to odd years from the present even-year cycle) also may be amended to delay phase-down of several other ground-based air navigation aids such as instrument landing systems (ILS).
The stretched-out schedule was proposed to accommodate the Federal Aviation Administration's (FAA's) recent decision to recommend setting back implementation of the GPS Wide Area Augmentation System (WAAS) to coincide more closely with development of Local Area Augmentation Systems (LAAS).
Dr. Chris Hegarty, an FAA consultant, updated the CGSIC audience on the current status of the new civil GPS signal design to be implemented (along with the current C/A code) on future generations of satellites at L1, L2, and the new L5 band centered on 1176.45 MHz. The signal will have a received power at user equipment four times higher than current civil signals. The chipping rate of the CDMA signal will be 10,230-10 times higher than the current C/A code. A dataless channel will be transmitted in parallel with a modulated channel bearing the GPS navigation message to enable carrier-phase techniques without the signal to noise ratio (SNR) degradation caused by data modulation.
Dr. Terry Moore, of the UK's University of Nottingham,
reported on developments with the European Union's (EU's) plans to develop a separate Global Navigation Satellite System (GNSS), Galileo, in cooperation with the European Space Agency (ESA). Working in a“definition phase”through the end of next year, the European Commission (EC, the EU's executive branch) and ESA have both committed more than $40 million each to investigate the technical, operational, and business issues that must be resolved to support a final decision to proceed with the estimated $2.5-3-billion program.
