Hostname: page-component-5c6d5d7d68-wp2c8 Total loading time: 0 Render date: 2024-08-18T07:26:55.189Z Has data issue: false hasContentIssue false
  • English
  • Français

Report of Special Commission 3 of IAG

Published online by Cambridge University Press:  12 April 2016

Erwin Groten
Erwin Groten*
Affiliation:
Institute of Physical Geodesy, Technical University of Darmstadt, Peterestr. 13, 64287, Darmstadt, Germany

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.

Since the last presentation of SC-3 on numerical values of fundamental geodetic parameters at the IAU General Assembly at Kyoto in 1997 there were some conceptual as well as fundamental numerical changes. The four basic parameters of geodetic (ellipsoidal) reference systems (GRS) can no longer be considered as constant with time: J2, a, ω, and GM have to be replaced by clearly (±10−8 or better) specified mean values or have to be associated with a specific epoch or, in case of GM, with specific reference frames (a = semi-major axis of Earth ellipsoid, J2 = second degree zonal harmonic of geopotential, ω = spin of Earth rotation). In case of (a, J2 ....) associated tidal reductions must be specifically defined in view of particular applications and significant differences between different tidal reduction types. Or we may replace “a” by a quantity which is independent of tides like the geopotential at the geoid, W0, where, however, also temporal changes are now discussed. The official geodetic reference systems such as GRS 80 and WGS 84 (revised in 97-form) are also no longer truly representing reality; a new system GRS 2000 is desired. We are, meanwhile, able to define and determine tidal and non-tidal (secular, periodic, aperiodic) variatipns of some fundamental geodetic parameters. Others are under investigation. New precession and/or nutation formulas to be adopted by IAU in 2000 or later would imply, again, changes in geodetic parameters such as H = hydrostatic flattening. Those and related other consequences are considered.

Type
Section 4. Time and Standards
Information
International Astronomical Union Colloquium , Volume 180: Towards Models and Constants for Sub-Microarcsecond Astrometry , March 2000 , pp. 337 - 352
Copyright
Copyright © US Naval Observatory 2000

References

Bursa, M., 1992, The four primary geodetic parameters, Studia geoph. et geod., 36, 199–206.CrossRefGoogle Scholar
Bursa, M., 1995, Special Commission 3, Fundamental Constants (SCFC), Report submitted to IAG, IUGG Gen. Ass., Boulder, Travaux IAG, Tome 30, 370–384.Google Scholar
Bursa, M., Kouba, J., Radej, K., True, S.A., Vatrt, V., Vojtiskova, M., 1997, Monitoring geoidal potential on the basis of Topex/Poseidon altimeter data and EGM 96. Geodesy on the Move, IAG Sci. Ass., Rio de Janeiro, Sept. 3-9, Springer Verlag, 352–358.Google Scholar
Bursa, M., Radej, K., Sima, Z., True, S.A., Vatrt, V., 1997, Tests for accuracy of recent Geopotential models, Intern. Geoid Service, Bulletin 6, 167–188.Google Scholar
Bursa, M., Kouba, J., Radej, K., True, S.A., Vatrt, V., Vojtiskova, M., 1998a, Monitoring Geoidal Potential on the Basis of Topex/Poseidon Altimeter Data, Aviso Altimetry Newsletters 6, 130–131.Google Scholar
Bursa, M., Kouba, J., Müller, A., Radej, K., True, S.A., Vatrt, V., Vojtiskova, M., 1998b, Determination of Geopotential Differences between local vertical Datums and realization of a world height system, Proc. Symp. IAG, München.Google Scholar
Bursa, M., Demianov, G.V., Yurkina, M.I., 1998c, On the determination of the earth’s model — the mean equipotential surface, Studia geoph. et geod., 42, 467–471.CrossRefGoogle Scholar
Bursa, M., Kouba, J., Radej, K., True, S.A., Vatrt, V., Vojtiskova, M., 1998d, Mean earth’s equipotential surface from Topex/Poseidon altimetry, Studia geoph. et geod., 42, 459–466.CrossRefGoogle Scholar
Bursa, M., Kouba, J., Radej, K., True, S.A., Vatrt, V., Vojtiskova, M., 1998e, Final Report on testing accuracy of geopotential models EGMX05, EGM 96. Intern. Geoid Service, Bulletin N. 7.Google Scholar
Bursa, M., Kouba, J., Kumar, M., Müller, A., Radej, K., True, S.A., Vatrt, V., Vojtiskova, M., 1999, Geoidal geopotential and world height system, Studia geoph. et geod., 43, 327–337.CrossRefGoogle Scholar
Cheng, M.K., Eanes, R.J., Tapley, B.D., 1992, Tidal deceleration of the Moon’s mean motion, Geophys. J. Int., 108, 401–409.CrossRefGoogle Scholar
Defraigne, P., Dehant, V., 1996, Toward new non-rigid Earth nutations, Proc. Journ. de Reference 1995, ed. Capitaine, N., Warsaw, 45–52.Google Scholar
Dickey, J.O., Bender, P.L., Faller, J.E., Newhall, XX, Ricklefs, R.L., Ries, J.G., Shelus, P.J., Veillet, C., Whipple, A.L., Wiant, J.R., Williams, J.G., Yoder, C.F., 1994, Lunar laser ranging: a continual legacy of the Apollo program, Science, 265, 482–490.CrossRefGoogle ScholarPubMed
Fukushima, T., 1993, IAU Standards - What’s it?, Proc. IAG. Gen. Ass. Beijing.Google Scholar
Fukushima, T., 1994, Time ephemeris. Proc. of 26th Symp. on “Cel. Mechanics”, Tokyo, Japan, Jan 12-13, eds. Kinoshita, H. and Nakai, H., 149–159.Google Scholar
Grafarend, E., Sanso, F., 1984, The multibody space-time geodetic boundary value problem and the Honkasalo term, Geophys. J. R. astr. Soc., 78, 255–275.CrossRefGoogle Scholar
Grafarend, E., Ardalan, A.A., 1997, W0: an estimate in the Finnish Height Datum N60, epoch 1993.4, from twenty-five GPS points of the Baltic Sea Level Project. J. Geodesy, 71, 673–679.CrossRefGoogle Scholar
Grafarend, E., Ardalan, A.A., 1999, The form parameters of the Somigliana-Pizetti level ellipsoid from current best estimates of fundamental geodetic parameters based on a functional analytical review of the Somigliana-Pizetti gravitational field, J. Geodesy, (in press).Google Scholar
Grafarend, E., Ardalan, A.A., 1999, World Geodetic Datum 2000, J. Geodesy, 73, 611–623.CrossRefGoogle Scholar
Groten, E., 1994, A comment on fundamental geodetic constants. IAG-SCFC 1991-1995, pres. at LAU General Ass. The Hague.Google Scholar
Groten, E., 1994, Global tidal parameters, Studia geoph. et geod., 38, 221–234.CrossRefGoogle Scholar
Kinoshita, H., 1994, Is the equatorial radius of the Earth a primary constant, or a defining constant?, Studia geoph. et geod., 38, 109–116.CrossRefGoogle Scholar
Kopejkin, S.M., 1991, Relativistic manifestations of gravitational fields in gravimetry and Geodesy, Manuscripta Geodaetica, 16, 301–312.Google Scholar
Lemoine, et al, 1996, The development of the NASA GSFC and NIMA joint geopotential model, Paper presented at IAG Symposium, Tokyo, Sept. 1996.Google Scholar
Marchenko, A.N. and Abrikosov, O.A., 1999, Evolution of the Earth principal axes and moments of inertia, J. Geodesy, (in press).Google Scholar
McCarthy, D.D., ed., 1992, IERS Standards. Technical Note 13, Observatoire de Paris.CrossRefGoogle Scholar
McCarthy, D.D., 1996, IERS Conventions.Google Scholar
Nerem, R.S., Chao, B.F., Au, A.Y., Chan, J.C., Klosko, S.M., Pavlis, N.K., Williamson, R.G., 1993, Temporal variations of the Earth’s gravitational field from satellite laser ranging to LAGEOS, Geophys. Res. Let., 20, 595–598.CrossRefGoogle Scholar
Nerem, R.S., Lerch, F.J., Williamson, R.G., Klosko, S.M., Robbins, J.W., Patel, G.B., 1994, Gravity model improvement using the DORIS tracking system on the SPOT 2 satellite, J. Geophys. Res., 99, B2, 2791–2813.CrossRefGoogle Scholar
Nerem, R.S., Lerch, F.J., Marshall, J.A., Pavlis, E.C., Putney, B.H., Tapley, B.D., Eanes, R.J., Ries, J.C., Schutz, B.E., Shum, C.K., Watkins, M.W., Klosko, S.M., Chan, J.C., Luthcke, S.B., Patel, G.B., Pavlis, N.K., Williamson, R.G., Rapp, R.H., Biancale, R., Nouel, F., 1994, Gravity model development for TOPEX/POSEIDON: Joint gravity models 1 and 2, J. Geophys. Res., 99, C12, 24, 421-24, 447.Google Scholar
Nesvorný, D., Šima, Z., 1994, Refinement of the geopotential scale factor R0 on the satellite altimetry basis, Earth, Moon, and Planets, 65, 79–88.CrossRefGoogle Scholar
NIMA, National Imagery and Mapping Agency, 1997, Technical Report TR 8350.2, Third Edition, Department of Defense, World Geodetic System, 1984, Its Definition and Relationships with Local Geodetic Systems.Google Scholar
Rapp, R.H., 1987, An estimate of equatorial gravity from terrestrial and satellite data, Geophys. Res. Lett., 14, 730–732.CrossRefGoogle Scholar
Rapp, R.H., 1993, Geoid undulation accuracy. IEEE Transaction on geoscience and remote sensing, 31, 365–370.CrossRefGoogle Scholar
Rapp, R.H., Yi, Y., Wang, Y.M., 1994, Mean sea surface and geoid gradient comparison with Topex altimeter data, J. Geophys. Res., 99, C12, 24, 657-24, 667.Google Scholar
Ries, J.C., Eanes, R.J., Shum, C.K., Watkins, M.M., 1992, Progress in the determination of the gravitational coefficient of the Earth, Geophys. Res. Lett., 19, 529–31.CrossRefGoogle Scholar
Ries, J.C., 1998, Personal communications.Google Scholar
Stephenson, F.R., Morrison, L.V., 1994, Long-term fluctuations in the Earth’s rotation: 700 BC to AD 1990, Phil. Trans. Royal Soc. (London) Ser. A.Google Scholar
Wang, Z., Kakkuri, J., 1998, The time dependency of gravity potential on the geoid, J. Geodesy, (in press).Google Scholar
Williams, J.G., Newhall, XX, Dickey, J.O., 1993, in Contributions of space geodesy to geodynamics: Earth Dynamics, eds. Smith, D.E., Turcotte, D.L., Geodynamics series 24, AGU, Washington, 83.Google Scholar
Williams, J.G., 1994, In Contributions to the Earth’s obliquity rate, precession and nutation, Astron. J., 108, 711–724.CrossRefGoogle Scholar
Yan, H.J., Groten, E., 1994, The celestial and terrestrial departure points and their various aspects in geodesy and astrometry, Studia geoph. et geod., 38, 117–130.CrossRefGoogle Scholar
Yurkina, M.I., 1993, Determination of Stokes’ constants respecting zero-frequency tidal term due to the Moon and the Sun, Studia geoph. et geod., 37, 317–325.CrossRefGoogle Scholar