Preliminary GRACE Geoids
In late July 2003, the first gravity products from the GRACE mission began to be released. These are geoid height maps based on three models issued by the University of Texas (UT) and the Geoforschungszentrum (GFZ) in Potsdam, Germany. All the maps shown below were generated by the author of this web site and have geoid height contours of 5 meters.
The first map below is based on spherical harmonic coefficients computed at UT. It is a combination solution of GRACE results combined with earlier space geodetic data used in the development of the TEG4, UT model. This model is complete to spherical harmonic degree and order 200, but only the terms up to degree and order 170 are plotted below.
The next model also comes from UT. It is based on the first 111 days of GRACE data. It is complete to spherical harmonic degree and order 120, all of which is plotted in the map below. One will note that there are some interesting north/south artifacts showing up in the Pacific and southern Indian Oceans.
This last model comes from GFZ. It is based on 39 days of data from GRACE acquired during periods of data acquisition in August and November, 2002. Again, one will note similar north/south artifacts in the southern ocean basins.
Last Modified: July 27, 2003