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NOS Hydrographic Survey DataHydrographic Survey Rap Sheets display survey summaries and locations, cross references, statistics, comprehensive platforms and correctors, processing and archive information. Survey types include Hydrographic, Field Edit, Reconnaissance, Lake, and Non-NOS sources. The National Ocean Service (NOS) Hydrographic Data Base (NOSHDB) and Hydrographic Survey Meta Data Base (HSMDB), both maintained by NOS and NGDC, provide extensive survey coverage and Federal Geographic Data Committee (FGDC) with Remote Sensing Extensions (RSE) metadata of the coastal waters and Exclusive Economic Zone (EEZ) of the United States and its territories. The NOSHDB contains digitized data from smooth sheets of hydrographic surveys completed between 1837 and 1965, and from survey data acquired digitally on NOS survey vessels since 1965. Over 76 million soundings from over 6,600 surveys are included in the NOSHDB. NGDC has developed an interactive map and data discovery tool, the Bathymetry Map Service, and a text-based search engine, the Hydrographic Survey Text Search, which enable rapid data discovery and download. The NOSHDB data with search and retrieval software are also available on a DVD-ROM or CD-ROM set. Data products from NOS surveys, including BAG files, Descriptive Reports, smooth sheet images, survey data images, textual gridded data, and geo-referenced sidescan sonar mosaics, FGDC/RSE metadata, and survey statistics are available for download from NGDC.
Bathymetric Attributed Grid (BAG) is a non-proprietary file format for storing and exchanging bathymetric data developed by the Open Navigation Surface Working Group. BAG files are gridded, multi-dimensional bathymetric data files and is the standard NOS hydrographic data file for public release. Current versions of the BAG file contain position and depth grid data, as well as position and uncertainty grid data, and the metadata specific to that BAG file, providing end users information about the source and contents of the BAG file. Please visit the Open Navigation Surface Working Group for additional information on BAG files.
Descriptive Reports (DRs) are approved metadata documents relevant to survey level hydrographic data and are available in Portable Document Format (PDF) form. The DR serves as a narrative document that describes the conditions under which the hydrographers performed the work and discusses various factors affecting the adequacy and accuracy of the results. Smooth Sheets are available from NGDC as images in Tagged Image File Format (TIFF) or Multi-resolution Seamless Image Database (MrSID) format. A smooth sheet is the final, neatly drafted, accurate plot of a hydrographic survey using verified or corrected data. NGDC archives and disseminates over 11,000 smooth sheets and over 8,000 DRs dating from the mid-1800s to the present. The survey data images, gridded data, and sidescan sonar mosaics are available only for recent surveys where NOS collected high-resolution data. Related Links:
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