Fig.6 Performance evaluation of different cap radii (Ψ ) 0 for different degrees of modification (P) Fig.7 RMS Error variations for selected cap radius of size (Ψ 0 = 1.50) with degrees of modification (P) Factor, J.K., Trimmer, R.G., Pavlis, N.K., Chinn, D.S., Cox, C.M., Klosko, S.M., Luthcke, S.B., Torrences, M.H., Wang, Y.M., Williamson, R.G., Pavlis, E.C., Rapp, R.H., Olson, T.R., 1998, The development of the joint NASA GSFC and the National Imagery and Mapping Agency (NIMA) geopotential model EGM 96, NASA/TP –1998- 206861. National Aeronautics and Space Administration Maryland, USA, 575pp. 6. Molodensky, M.S., Eremeev, V.F., Yurkina, M.I.,1962. Methodes for study of the external gravitational field and figure of the Earth. The Israeli Programme for the translation of Scientific Publications, Jerusalem, Israel, 248 pp. 7. Nagarajan,B.,1994.Definition and realization of a global vertical Datum,Report N0.427,Deptt. Of Geodetic Science ,The Ohio State University,Columbus,Ohio. 8. Nagarajan, B., Singh, S.K.,, 2005. On the Derivation of Orthometric Heights from COORDINATES IS AVAILABLE FOR FREE DOWNLOAD www.mycoordinates.org GPS-Levelling Observations. GIS Development, 9(4). 9. Stokes, G.G., 1849. On the variation of gravity on the surface of the Earth. Transaction of Cambridge Philosophical Society 8, 672-695. 10. Vanic̃ek P., Sjöberg, L.E., 1981. Reformulation of Stoke’s theory of higher than second-degree reference field and modification of integration Kernels. Journal of Geophysical Research – Solid Earth 96 (B4), 6529 – 6539. 11. Vanic̃ek P., Featherstone, W.E., 1998. Performance of three types of Stoke’s Kernel in the combined solution for the geoid, Journal of Geodesy 72 (12), 684-697. 12. Vanic̃ek P., Kleusberg, A., 1987. The Canadian geoid- Stokesian approach manuscript a geodaetica 12 (2), 86-98. 13. Wong L., Gore, R., 1969. Accuracy of geoid heights from modified Stokes Kernel, Geophysical Journal of the Royal Astronomical Society 18, 81-91. 12 April 2006 SK Singh Geodetic & Research Branch, Survey of India, Dehradun, India gandrb@vsnl.net.in Brig (Dr) B Nagarajan Geodetic & Research Branch, Survey of India, Dehradun, India gandrb@vsnl.net.in PKGarg Department of Civil Engineering, Indian Institute of Technology, Roorkee, India gargpfce@iitr. ernet.in
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