The NGS GEOID Page

First created 3/01/2000. DAS.

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What is the geoid? (Definition, History)	What is a deflection of the vertical? (Definition, History)	What geoid and deflection models has NGS made in the last decade? (Updated 1/4/2001 to include the 1990-1994 models)
The latest models: GEOID03, USGG2003, GEOID99, G99SSS , G99BM , and DEFLEC99 An update to the GEOID03 model has been postponed until possibly 2006
Comparison of the latest models with other geoid models
Geoid Links (Agencies, Models)	Research Links (Projects at least loosely tied to the geoid)	Ongoing geoid research projects at NGS (Papers in review, currently unpublished research topics)
Online papers about the geoid	Who uses the geoid? (Studies with NGS geoid models)	NGS geoid research software
Online slideshow presentations	Absolute Gravimeter	Cryogenic Gravimeter