National Geodetic Vertical Datum of 1929

The National Geodetic Vertical Datum of 1929 (NGVD29), originally known as the Sea Level Datum of 1929, is the vertical datum established for vertical control surveying in the United States of America by the General Adjustment of 1929. NGVD29 was determined and published by the United States Coast and Geodetic Survey and is used to measure the elevation of a point above and below mean sea level (MSL).

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