secular and tesseral harmonic perturbations are included. However, in the case when longperiod perturbations (which depend mainly on odd zonal harmonics) are included, the
large differences are for inclinations from 60° to 120°. The differences calculated using
GRIM4-S4P and JGM-3 are larger than for other models for inclinations from 80° to 100°
when zonal harmonic coefficients are included (secular and long-period perturbations
cases) and for the other inclinations when tesseral harmonic coefficients are included
(fig. I).
ACKNOWLEDGMENT
This work has been partly supported by Polish Committee for Scientific Research under
the grant No 10301P03/95/08.
REFERENCES
Decker, B.L., 1986, World Geodetic System 1984, Proceedings o/the Fourth Interna
tional Geodetic Symposium on Satellite Positioning, University of Texas, Austin, May
1986.
Hoots, F.R, 1994, The Need for New Algorithms, In Proceedings 0/ the ArtifiCial Satellite Theory Workshop held at the U.S.Naval Observatory,Nov., 1993, P.K.Siedelmann
and B.Kaufinan, (Eds.), U.S.Naval Observatory, Washington, pp. 1-11.
Lerch, F. J., 1994, A geopotential model from satellite tracking, altimeter, and surface
gravity data: GEM-T3, J. Geophys. Res., vol 99, No. B2, pp. 2815-2839.
Nerem, R S., et. al., 1994b, Gravity Model Development for TOPEXIPOSEIDON: Joint
Gravity Models 1 and 2, J. Geophys. Res., vol. 99, No. C12, pp. 24,421-24,447.
Nerem, R S., F. J. Lerch, R G. Williamson, S. M. Klosko, J. W. Robbins, and G. B.
Patel, Gravity model improvement using the DORIS tracking system on the SPOT 2
satellite, 1994a, J. Geophys. Res., vol. 99, No. B2, pp. 2791-2813.
Rapp, RH., Y.M. Wang, and N.K. Pavlis, 1991, The Ohio State 1991 Geopotential and
Sea Surface Topography Harmonic Coefficient Models, Dept. o/Geodetic Science
and Surveying, The Ohio State University, Report No.410, Columbus, Ohio, August
1991.
Schwintzer, P. et al., 1992, Improvement ofGRIM4 Earth Gravity Models Using
GEOSAT Altimeter and SPOT-2 and ERS-I Tracking Data, Proceedings o/the IAGSymp. No 112 "Geodesy and Physics o/the Earth", Potsdam 1992.
Schwintzer, P., 1995, private communication.
206
large differences are for inclinations from 60° to 120°. The differences calculated using
GRIM4-S4P and JGM-3 are larger than for other models for inclinations from 80° to 100°
when zonal harmonic coefficients are included (secular and long-period perturbations
cases) and for the other inclinations when tesseral harmonic coefficients are included
(fig. I).
ACKNOWLEDGMENT
This work has been partly supported by Polish Committee for Scientific Research under
the grant No 10301P03/95/08.
REFERENCES
Decker, B.L., 1986, World Geodetic System 1984, Proceedings o/the Fourth Interna
tional Geodetic Symposium on Satellite Positioning, University of Texas, Austin, May
1986.
Hoots, F.R, 1994, The Need for New Algorithms, In Proceedings 0/ the ArtifiCial Satellite Theory Workshop held at the U.S.Naval Observatory,Nov., 1993, P.K.Siedelmann
and B.Kaufinan, (Eds.), U.S.Naval Observatory, Washington, pp. 1-11.
Lerch, F. J., 1994, A geopotential model from satellite tracking, altimeter, and surface
gravity data: GEM-T3, J. Geophys. Res., vol 99, No. B2, pp. 2815-2839.
Nerem, R S., et. al., 1994b, Gravity Model Development for TOPEXIPOSEIDON: Joint
Gravity Models 1 and 2, J. Geophys. Res., vol. 99, No. C12, pp. 24,421-24,447.
Nerem, R S., F. J. Lerch, R G. Williamson, S. M. Klosko, J. W. Robbins, and G. B.
Patel, Gravity model improvement using the DORIS tracking system on the SPOT 2
satellite, 1994a, J. Geophys. Res., vol. 99, No. B2, pp. 2791-2813.
Rapp, RH., Y.M. Wang, and N.K. Pavlis, 1991, The Ohio State 1991 Geopotential and
Sea Surface Topography Harmonic Coefficient Models, Dept. o/Geodetic Science
and Surveying, The Ohio State University, Report No.410, Columbus, Ohio, August
1991.
Schwintzer, P. et al., 1992, Improvement ofGRIM4 Earth Gravity Models Using
GEOSAT Altimeter and SPOT-2 and ERS-I Tracking Data, Proceedings o/the IAGSymp. No 112 "Geodesy and Physics o/the Earth", Potsdam 1992.
Schwintzer, P., 1995, private communication.
206