EGM96: The NASA GSFC and NIMA Joint Geopotential Model

NASA Logo OSU Logo NIMA Logo



The NASA GSFC and NIMA Joint Geopotential Model

Greetings! Welcome to the official webpage of the NASA and NIMA joint geopotential model, EGM96. EGM96 is a spherical harmonic model of the Earth's gravitational potential complete to degree and order 360.

The model coefficients, and other products are available via anonymous FTP to (cd to the directory pub/egm96/general_info/). Click here to retrieve the Model Coefficients, and other products.

The major reference for this model is NASA/TP-1998-206861:

The Development of the Joint NASA GSFC and NIMA Geopotential Model EGM96,
F. G. Lemoine, S. C. Kenyon, J. K. Factor, R.G. Trimmer, N. K. Pavlis, D. S. Chinn, C. M. Cox, S. M. Klosko, S. B. Luthcke, M. H. Torrence, Y. M. Wang, R. G. Williamson, E. C. Pavlis, R. H. Rapp and T. R. Olson,
NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771 USA,
July 1998.

EGM96 Anomalies to L=360

EGM96 Geoid

EGM96 Geoid courtesy of J. Frawley/NASA GSFC

30'x30' value of the geoid undulations from EGM96 to 360x360. The image is shown on a Robinson projection of the Earth. Geoid undulations from N. Pavlis (RITSS/NASA GSFC), and image courtesy of J. Frawley (NASA GSFC)>

Model Description.



Table of Contents.


How to retrieve the Model Coefficients, and other products.

Get the EGM96 Geoid Grid.

View the EGM96 geoid.

Orbit Error Predictions Using JGM-2S, EGM96S, JGM3, TEG3, and EGM96 for various satellite orbits.

Read about PGM2000A

(PGM2000A is an EGM96 derivative model that incorporates normal equations for the dynamic ocean topography implied by the POCM4_B ocean circulation model).


Send questions or comments to: or
Last revised February 24, 2002 21:05 UTC.