A high-resolution geoid for the United States



The National Oceanic and Atmospheric Administrations's National Geodetic Survey is computing a high-resolution geoid height model for the conterminous United States. The model, known as GEOID90, should be available from NGS in December 1990. These geoid heights will be referred to as the Geodetic Reference System of 1980 (GRS 80) and will be appropriate for use with measurements from the Global Positioning System.