The design plans discussed so far include options for a 21-or36-satellite middle-earth-orbit constellation plus communication satellites. Several frequency options are under consideration as the transmission bands for a code-division multiple access (CDMA) signal service that would provide 10-meter positioning accuracy and 33-nanosecond timing (95 percent), according to Moore.
At the CGSIC's timing subcommittee meeting on Sunday, Mihran Miranian, of the U.S. Naval Observatory (USNO) time division, described the new multichannel GPS timing receivers that have recently arrived at the nation's (and GPS system's) timekeepers. The prototype 12-channel TTR12s are basically dual-frequency (Ll/L2) Allen Osborne Associates TurboRogue receivers modified for time-transfer applications. According to Miranian, the TTR12s have an improved external time-reference locking unit and improved time control for l pulse per second (PPS) comparisons.
When“keyed”to operate under antispoofing (encrypted) conditions, they can use the GPS Precise Positioning Service (PPS)-both code and carrier phase from the P-code signals-in addition to the C/A-code and carrier available with the current single-channel receivers that dominate the precise timing centers of the world. Maranian says the USNO will use the units to maintain GPS system time and Coordinated Universal Time (UTC) corrections as well as for common-view and two-way time transfer applications.
Joe Canny, deputy assistant secretary of transportation and CGSIC chairman, and Scott Pace, of the RAND Corporation's Critical Technologies Institute provided updates on U.S. efforts to preserve and extend GPS spectrum allocations.
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3.2.3.2 Racal's Role in EGNOS and Galileo
Racal (booth G) has won a series of development and initial production contracts valued at around $16 million, which give the company a significant role in the development of the European Geostationary Navigation Overlay Service (EGNOS) and the Galileo satellite navigation system. Working with NovAtel, Racal will supply Ranging and Integrity Monitoring Stations for EGNOS. To validate the Galileo signal structure, Racal will develop a signal generator, work with subcontractors at Dassault-Sercel to develop a prototype receiver, and work with the UK Defence Evaluation and Research Agency to carry out system testing.
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