Fine Tuning GPS Clock Estimation in the MCS

Abstract

With the completion of a 24 operational satellite constellation, GPS is fast approaching the critical milestone, Full Operational Capability (FOC). Although GPS is well capable of providing the timing accuracy and stability figures required by system specifications, the GPS community will continue to strive for further improvements in performance. The GPS Master Control Station (MCS) recently demonstrated that timing improvements are always possible, provided we don't sacrifice system integrity in the process. The most recent improvements have concentrated on a re-evaluation of the MCS Kalman Filter's Continuous Time Update Process Noises, also known as qs. Rubidium (Rb) qs received notable (and well needed) attention in early 1994. In late 1994, the MCS completely re-messed the qs for all individual GPS frequency standards By tuning MCS clock estimation on a satellite-by-satellite basis, we've safely optimized the utility of the GPS Composite Clock, and hence, Kalman Filter state estimation, providing a small improvement to user accuracy.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1994
Accession Number
ADA496087

Entities

People

  • Steven T. Hutsell

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Artificial Satellites
  • Clocks
  • Communities
  • Composite Materials
  • Databases
  • Equations
  • Errors
  • Filters
  • Frequency
  • Frequency Standards
  • Kalman Filters
  • Measurement
  • Metal Matrix Composites
  • Navigation
  • Standards
  • United States

Readers

  • Positioning, Navigation, and Timing (PNT) Technology.
  • Systems Analysis and Design

Technology Areas

  • Space
  • Space - Satellites