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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