Time Transfer from Combined Analysis of GPS and TWSTFT Data

Abstract

This paper presents the time transfer results obtained from the combination of GPS data and TWSTFT data. Two different methods are used for the combination: a first one (named CV+TW) is based on a least-squares analysis of GPS code and carrier-phase measurements in common view, constrained by TWSTFT data. Using the Vondrak-Cepek algorithm, the second approach (named PPP+TW) combines the TWSTFT time transfer data with the GPS clock solutions computed with Precise Point Positioning. Combining GPS and TWSTFT considerably increases the robustness of the accurate time transfer result due to the complete independence between the two spatial techniques. Both combination methods provide a time transfer solution which benefits from the high short-term stability and high resolution of the GPS data and the high accuracy of the TWSTFT data. The PPP+TW solution is continuous, while some discontinuities exist in the solution CV+TW, due to the noise and diurnal perturbation in the TW data. In general, the solutions obtained with both methods agree well with each other. The r.m.s. of the differences between the results remains below 300 picoseconds for the links investigated.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2008
Accession Number
ADA503895

Entities

People

  • Jiang Zhu
  • M. Chow-Martínez
  • Pascale Defraigne

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Algorithms
  • Artificial Satellites
  • Boundaries
  • Calibration
  • Clocks
  • Continuity
  • Discontinuities
  • Electronic Mail
  • Frequency
  • High Resolution
  • Ku Band
  • Measurement
  • Observation
  • Phase Measurement
  • Time Intervals
  • X Band

Readers

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

Technology Areas

  • Space