Hostname: page-component-77c89778f8-5wvtr Total loading time: 0 Render date: 2024-07-22T20:34:02.547Z Has data issue: false hasContentIssue false

The Definition and Stability of Local Inertial Reference Frames

Published online by Cambridge University Press:  19 July 2016

R. N. Treuhaft
Affiliation:
Jet Propulsion Laboratory, California Institute of Technology 4800 Oak Grove Drive Pasadena, California 91109, USA
S. T. Lowe
Affiliation:
Jet Propulsion Laboratory, California Institute of Technology 4800 Oak Grove Drive Pasadena, California 91109, USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Inertial reference frames spanning approximately 10°-30° square on the sky and capable of locating objects to few-hundred microarcsecond accuracies are useful for a broad class of astrometric measurements. Deep space tracking and general relativistic angular deflection experiments are examples of astrometric measurements which can profitably reference the positions and/or motions of objects to a field of radio sources in a local frame. A method for defining local inertial reference frames has been developed based on Very Long Baseline Interferometry (VLBI) measurements of extragalactic radio sources. By observing the radio emission from the object to be located in the frame, as well as that from about five radio sources which define the frame, dominant systematic astrometric errors can be minimized through parameter estimation. The entire reference frame measurement is of the order of 30 minutes including all the sources in a frame. The limiting error for single-epoch position determination in a local frame is the unknown structure of both target and reference objects. Structure can cause systematic milliarcsecond-level errors. The limiting error for epoch-to-epoch differential position measurements is tropospheric fluctuations, assuming that the radio source structures do not change from one epoch to the next. Preliminary results of an epoch-to-epoch measurement of relativistic gravitational deflection by Jupiter, in which the total deflection was about 600 microarcseconds, suggest that the local reference frame is stable at the 240-microarcsecond level over twelve days. Data have been taken at longer time intervals to determine the annual stability of the frames. At the time of preparation of these proceedings, those data have not yet been analyzed.

Type
Part 4: Realization and comparison of reference frames
Copyright
Copyright © Kluwer 1990 

References

REFERENCES

Bierman, G. J., Factorization Methods for Discrete Sequential Estimation , Academic Press, New York, 169, 169. Charlot, P., “Radio Source Structure in Astrometric and Geodynamic VLBI,” submitted to Astronomical Journal , 1990.Google Scholar
Ma, C., “The Realization of an Inertial Reference Frame from VLBI,” in proceedings of IAU Symposium 141, 1989.Google Scholar
Marcaide, J. M. and Shapiro, I. I., “High-Precision Astrometry via Very Long Baseline Radio Interferometry: Estimate of the Angular Separation Between the Quasars 1038+528A and B,” Astronomical Journal , 88, 1133, August 1983.Google Scholar
Porcas, R. W., “Summary of Known Superluminal Sources,” in Superluminal Radio Sources , ed. Zensus, J. A., and Pearson, T. J., Cambridge University Press, Cambridge, p. 18, 1987.Google Scholar
Reasenberg, R. D., Shapiro, I. I., MacNeil, P. E., Goldstein, R. B., Breidenthal, J. C., Brenkle, J. P., Cain, D. L., Kaufman, T. M., Komarek, T. A., and Zygielbaum, A. I., “Viking Relativity Experiment: Verification of Signal Retardation by Solar Gravity,” Astrophysical Journal , 234, L219, December 1979.Google Scholar
Sovers, O. J., Edwards, C. D., Jacobs, C. S., Lanyi, G. E., Liewer, K. M., and Treuhaft, R. N., “Astrometric Results of 1978-1985 Deep Space Network Radio Interferometry: The JPL 1987-1 Extragalactic Source Catalog,” Astronomical Journal , 95, 1647, June 1988.CrossRefGoogle Scholar
Sovers, O. J., “An Extragalactic Reference Frame from DSN VLBI Measurements-1989,” in proceedings of IAU Symposium 141, 1989.Google Scholar
Treuhaft, R. N. and Lanyi, G. E., “The Effect of the Dynamic Wet Troposphere on Radio Interferometric Measurements,” Radio Science , 22, 251, March 1987.CrossRefGoogle Scholar
Treuhaft, R. N., “Deep Space Tracking in Local Reference Frames,” Jet Propulsion Laboratory Telecommunications and Data Acquisition Progress Report , 42-94, 1, August 1988.CrossRefGoogle Scholar