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WAAS Network Time Performance Using WRS Data

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Conference paper

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Raytheon Systems Company is currently designing the algorithms of the FAAs Wide Area Augmentation System WAAS. This paper will briefly overview the WAAS network time WNT algorithms and their integration into the overall system. The WAAS system is required to provide users with orbit, clock, and ionosphere corrections for single-frequency measurements of the GPS signal. The clock corrections will be made in the WAAS network time WNT reference scale. This reference scale is required to track the GPS time scale, while at the same time providing the users with the translation to UTC. This design must provide the user a seamless transition when switching from one WMSs WNT realization to another. This paper expands on two previous papers, one presented at ION GPS-97 using simulated clock data as input, and the other presented at the I999 Technical Meeting using receiver data from the National Satellite Testbed NSTB and preliminary WAAS data. We included some introductory sections from previous papers here for completeness. Here, we will present the performance results of the WNT algorithm using GPS clock and receiver data from WAAS Reference Station WRS using the standalone WNT algorithm with the WAAS prototype software. We will also show some recent WNT algorithm results from the operational WAAS software, indicating that the WNT design should meet the aforementioned requirements, taking into account possible WAAS WMS switches.

Subject Categories:

  • Test Facilities, Equipment and Methods
  • Air Navigation and Guidance
  • Unmanned Spacecraft

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