NOAA's National Geodetic Survey defines and manages the [A] - a consistent coordinate system that defines latitude, longitude, height, scale, gravity, and orientation throughout the United States.In addition to a network of continuously operating reference stations (CORS) supporting three-dimensional positioning activities (shown here), the ___A____ includes a network of permanently marked points; a consistent, accurate, and up-to-date national shoreline; and a set of accurate models describing dynamic, geophysical processes that affect spatial measurements