New U.S. Absolute Gravity Program

The National Geodetic Survey of the National Oceanic and Atmospheric Administration (NOAA/NGS) and the Hydrographic and Topographic Center of the Defense Mapping Agency (DMA/HTC) began a program of very accurate measurements of the earth's gravity field in December 1986. The primary purposes of the program are to establish and maintain a high-accuracy nationwide absolute gravity reference network and to support research in geophysics and geodynamics.