The National Oceanographic Data Center includes the National Coastal Data Development Center (NCDDC) and the NOAA Central Library, which are integrated to provide access to the world's most comprehensive sources of marine environmental data and information. NODC maintains and updates a national ocean archive with environmental data acquired from domestic and foreign activities and produces products and research from these data which help monitor global environmental changes. These data include physical, biological and chemical measurements derived from in situ oceanographic observations, satellite remote sensing of the oceans, and ocean model simulations.