Mexico Terrain Corrected Free Air Anomalies (97) |
This 2? gravity anomaly grid for Mexico, North-Central America and the Western Caribbean
Sea is NOT the input data set used in the development of the MEXICO97 model. This
gravity grid represents one million gravity measurements held in the NGS gravity database
as of March 1997. The data used in this grid have NOT been augmented by gravity data
contributions from NGA (former National Imagery and Mapping Agency), but have been
augmented by 2?x2? satellite-altimeter-derived gravity anomalies computed by Sandwell
and Smith (1997). Please note that the MEXICO97 geoid model does contain the NGA (former
National Imagery and Mapping Agency) contributions. Large data gaps south of 20 degrees
North latitude were filled with15?x15? gravity values derived from the EGM96 global
geopotential model. The gravity values are based on the International Gravity Standardization
Net 1971 (IGSN71). The geoid heights are referred to the Geodetic Reference System
1980 (GRS80) ellipsoid, centered at the origin of the International Terrestrial Reference
Frame 1994 (ITRF94(1996.0)). Additional information is available at:http://www.ngs.noaa.gov |
|