Metadata Identifier: gov.noaa.ngdc.mgg.dem:standrew_bay_g110_30m

Aggregation Info | Bands | Citations | Constraints | Coverage Descriptions | Dimensions | Extents | Formats | Geographic Bounding Box
Georectified Information | Georeferenceable Information | Identifiers | Instruments | Mediums | OnlineResources | Operations
Platforms | Process Steps | Range Elements | Reference Systems | Responsible Parties | Series | Sources | Spatial Grids | Temporal Extents

MD_DataIdentification

Count Component Title Abstract
1 St. Andrew Bay, FL (G110) Bathymetric Digital Elevation Model (30 meter resolution) Derived From Source Hydrographic Survey Soundings Collected by NOAA Bathymetry for St. Andrew Bay was derived from eleven surveys containing 93,025 soundings. Seven overlapping, older, less accurate surveys were omitted entirely. Two older surveys had overlapping portions deleted for the same reasons. The average separation between soundings was 52 meters. One survey in the north dated from 1935; the rest dated from 1983 to 1988. The range of soundings for the eleven surveys was 2.9 meters to -19.0 meters at mean low water. Mean high water values of 0.4 or 0.5 meters were assigned to the shoreline. Twenty-one points were found that were not consistent with the surrounding points. These were removed prior to tinning. DEM grid values outside the shoreline (on land) were assigned null values (-32676). St. Andrew Bay has nine 7.5 minute DEMs and a single one degree DEM. The 1 degree DEMs were generated from the higher resolution 7.5 minute DEMs which covered the estuary. A Digital Elevation Model (DEM) contains a series of elevations ordered from south to north with the order of the columns from west to east. The DEM is formatted as one ASCII header record (A- record), followed by a series of profile records (B- records) each of which include a short B-record header followed by a series of ASCII integer elevations (typically in units of 1 centimeter) per each profile. The last physical record of the DEM is an accuracy record (C-record). The 7.5-minute DEM (30- by 30-m data spacing) is cast on the Universal Transverse Mercator (UTM) projection. It provides coverage in 7.5- by 7.5-minute blocks. Each product provides the same coverage as a standard USGS 7.5-minute quadrangle but the DEM contains over edge data. Coverage is available for many estuaries of the contiguous United States but is not complete.
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SV_Identification

none found
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CI_Citation

Count Component Title Date Citation Identifier
1 Entity and Attribute Information
    1 Global Change Master Directory (GCMD) Horizontal Data Resolution Keywords
      1 Global Change Master Directory (GCMD) Science Keywords
        1 Global Change Master Directory (GCMD) Vertical Data Resolution Keywords
          1 Mean Lower Low Water depth
            2012-08-10
          1 Medium Resolution Vector Shoreline
            1994-01-01
          1 NOAA NOS Estuarine Bathymetry
            1999-01-01
          1 National Ocean Service- Hydrographic Survey Data
            1997-01-01
          1 None
            1 Project control
              1992-05-03
            1 St. Andrew Bay, FL (G110) Bathymetric Digital Elevation Model (30 meter resolution) Derived From Source Hydrographic Survey Soundings Collected by NOAA
              1998-06-06
            1 Uncontrolled
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              CI_Series

              none found
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              CI_ResponsibleParty

              Count Component Individual Organization Position Email Role Linkage
              1 resourceProvider https://epsg.org/crs_5866/MLLW-depth.html
              1 Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Special Projects (SP) originator
              1 EPSG Registry European Petroleum Survey Group publisher https://epsg.org/home.html
              5 DEM Info NOAA National Centers for Environmental Information DEM Information dem.info@noaa.gov pointOfContact
              1 NOAA's National Ocean Service, Special Projects (SP) publisher
              1 NOAA's Ocean Service publisher
              1 NOAA, National Environmental Satellite, Data and Information Service (NESDIS), National Geophysical Data Center (NGDC) publisher
              1 National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS) originator
              1 National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Special Projects originator
              1 National Oceanic and Atmospheric Administration(NOAA), National Ocean Service (NOS), Special Projects (SP) Chief, Integrated Planning and Technical Services robert.wilson@noaa.gov originator
              1 National Oceanic and Atmospheric Administration(NOAA), National Ocean Service (NOS), Special Projects (SP) Chief, Integrated Planning and Technical Services robert.wilson@noaa.gov publisher
              1 National Oceanic and Atmospheric Administration(NOAA), National Ocean Service (NOS), Special Projects (SP) Chief, Integrated Planning and Technical Services robert.wilson@noaa.gov pointOfContact
              1 U.S. Geological Survey publisher
              1 United States Geologic Survey (USGS) or NOAA's National Geodetic Survey (NGS) originator
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              CI_OnlineResource

              Count Component Linkage Name Description Function
              1 https://epsg.org/crs_5866/MLLW-depth.html MLLW depth GML for Mean Lower Low Water vertical coordinate reference system (in meters) available from the epsg-registry. information
              1 https://epsg.org/home.html European Petroleum Survey Group Geodetic Parameter Registry Registry that accesses the EPSG Geodetic Parameter Dataset, which is a structured dataset of Coordinate Reference Systems and Coordinate Transformations. search
              2 https://www.ngdc.noaa.gov/mgg/bathymetry/estuarine project web page text search search
              1 https://www.ngdc.noaa.gov/thredds/dodsC/regional/standrew_bay_g110_30m.nc.html OPeNDAP Dataset Access Form OPeNDAP Dataset Access Form download
              1 https://www.ngdc.noaa.gov/thredds/fileServer/regional/standrew_bay_g110_30m.nc Download NetCDF File Download NetCDF File download
              1 https://www.ngdc.noaa.gov/thredds/ncml/regional/standrew_bay_g110_30m.nc?catalog=https%3A%2F%2Fwww.ngdc.noaa.gov%2Fthredds%2Fcatalog%2Fregional%2Fcatalog.html&dataset=regionalDatasetScan%2Fstandrew_bay_g110_30m.nc NetCDF Markup Language file NetCDF Markup Language file information
              1 https://www.ngdc.noaa.gov/thredds/ncss/regional/standrew_bay_g110_30m.nc/dataset.html Download a subset of the NetCDF Download a subset of the NetCDF download
              1 https://www.ngdc.noaa.gov/thredds/wcs/regional/standrew_bay_g110_30m.nc?service=WCS&version=1.0.0&request=GetCapabilities Web Coverage Service GetCapabilities Web Coverage Service GetCapabilities information
              1 https://www.ngdc.noaa.gov/thredds/wms/regional/standrew_bay_g110_30m.nc?service=WMS&version=1.3.0&request=GetCapabilities Web Map Service GetCapabilities Web Map Service GetCapabilities information
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              MD_Identifier or RS_Identifier

              Count Component Code
              1 26916
              1 G220
              1 urn:ogc:def:crs:EPSG::5866
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              EX_Extent

              Bounding Box Temporal Extent
              Count Component Description West East North South Start End
              1 -85.861141 -85.385152 30.314575 30.014344
              2 1935-01-01 1988-01-01
              1 1970-01-01 1990-01-01
              1
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              EX_GeographicBoundingBox

              Count Component West East North South
              1 -85.861141 -85.385152 30.314575 30.014344
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              EX_TemporalExtent

              Count Component Start End
              2 1935-01-01 1988-01-01
              1 1970-01-01 1990-01-01
              1
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              MD_Format

              Count Component Name Version specification
              1 netCDF 4 Classic netCDF 4 Classic
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              MD_Medium

              none found
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              MD_Constraints

              Count Component Use Limitation
              1 not for navigation Not to be used for navigation. Although these data are of high quality and useful for planning and modeling purposes, they are not suitable for navigation. For navigation, please refer to the NOS nautical chart series.
              1 copyright statement Produced by the NOAA National Centers for Environmental Information. Not subject to copyright protection within the United States.
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              MD_ReferenceSystem

              Count Component Code Authority Title
              1 26916
              1 Mean Lower Low Water depth urn:ogc:def:crs:EPSG::5866 Mean Lower Low Water depth
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              MD_GridSpatialRepresentation

              none found
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              MD_Georeferenceable or MI_Georeferenceable

              none found
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              MD_Georectified or MI_Georectified

              Count Component Number of Dimensions Cell Geometry Code
              1 2 area
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              MD_Dimension

              Count Component Name Code Size
              1 column 1515
              1 row 1091
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              MD_CoverageDescription or MI_CoverageDescription

              none found
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              MD_Band or MI_Band

              Count Component Identifier Descriptor
              1 GDAL Band Number 1
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              MI_RangeElementDescription

              none found
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              MD_AggregateInformation

              Count Component Title Code Association Type Code
              1 G220 crossReference
              1 NOAA NOS Estuarine Bathymetry largerWorkCitation
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              LE_Source or LI_Source

              Count Component Title Date Description
              1 Medium Resolution Vector Shoreline 1994-01-01 Source Contribution: Shoreline position; Source Type: CD-ROM
              1 National Ocean Service- Hydrographic Survey Data 1997-01-01 Source Contribution: Hydrographic Soundings; Source Type: CD-ROM
              1 Project control 1992-05-03 Source Contribution: Ground control points; Source Type: magnetic tape
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              LE_ProcessStep or LI_ProcessStep

              Count Component DateTime Description
              1 The production procedures, instrumentation, hardware, and software used in the collection of standard National Oceanic and Atmospheric Administration (NOAA) Bathymetric Digital Elevation Models (DEMs) vary depending on systems used at the time of the survey. Log sheets were kept at all stages of processing to track file names,dates, hydrographic survey coverage, and soundings or hydrographic surveys that were deleted as part of the quality control process. A short summary of the processing steps for each estuary is available on the individual data pages. In addition, a list of each of the surveys which were included is accessible through the individual data pages. Original hydrographic data from the National Ocean Service and it predecessors was used exclusively as source data. Processing was performed on desktop computers using a variety of commercial and custom software systems. The two main software systems used were Digital Optimization of Grid Systems (DOGS) version 1.5x software developed by NOAA and MapInfo Professional version 4.5 published by MapInfo augmented by a MapInfo add-on named Vertical Mapper published by Northwood Geosciences. The processing sequence for each estuary started with the generation of a comprehensive source data set from the NOS archives, These source sounding were quality controlled to eliminate outliers and superseded surveys, optimized to reduce the number of data values, augmented with points representing the Mean High Water shoreline, and then gridded. The gridded data sets were converted from the internal proprietary grid format to Digital Elevation Model (DEM) format for public distribution. Creating Point Sets of Hydrographic Survey Data: Sounding data obtained from Hydrographic Surveys were extracted using DOGS from the GEODAS CD distributed by the National Geophysical Data Center using each estuary's shoreline as a clipping boundary. Large estuaries were broken into several overlapping regions and subsets of points were extracted and processed. Most historic hydrographic surveys are included on the GEODAS CD. For those regions which were missing data (parts of southern Florida and Chesapeake Bays only), soundings were digitized from a hard copy smooth sheets generated by the Hydrographic Surveys. Editing and Quality Control of Bathymetry Point Data: The first step of the quality control was to review the data using the DOGS software. The data were first examined for surveys or parts of surveys that are redundant. For many areas there are more surveys than are actually useful. Entire surveys or large portions of surveys were deleted for the following reasons: Another more recent survey fully covers the same area. The survey has questionable values which can not be fixed by way of figuring out a mathematical update value for the entire survey, and there are too many bad points to pick out probable "good" values. Sections of surveys were omitted if they were overlapped by more accurate surveys or by similar yet denser coverage. The second step was to display the data by depth values and to remove stray points that were obvious outliers from the surrounding data values. Optimizing the Bathymetry Point Data using DOGS: The data was first triangulated in DOGS in order to optimize the set of points. The computer program DOGS can analyze a large set of bathymetric data and create from it a smaller set of optimized points which describes the bathymetry of a geographic region to within a user defined error. This smaller data set then can be used on its own as a representation of the area's bathymetry, or as input in to other computer programs or Geographical Information Systems. There are two calculation options for triangulation in DOGS: relative and absolute. Bathymetry point files were cut into sections for separate processing based on mean depth of 10 meters. A relative height error criteria of 0.01 was used for the triangulation of regions whose depths averaged above 10 meters. An absolute height error criteria of 0.1 meters was used for areas with average depths less than 10 meters. The two resultant files were saved as text files. After combining these files, the vertical error associated with the optimized data set was 1 percent of depth or 0.1 meters, whichever was greater. The optimized DOG file was imported into MapInfo's MapInfo Professional desktop mapping software. Augmenting the data set with Shoreline Points: The final bathymetry was clipped to NOAA's 1:250,000 Coastal Assessment Framework (CAF) shoreline. A copy of the shoreline file was edited to create a point file from the vector vertices and optimized using DOGS to produce a more workable, smaller file, with little compromise to the shape of the shoreline. Mean High Water tide level was assigned to the shoreline points to give them a height. These Shoreline data points were added to the set of bathymetry points before doing the final triangulation in MapInfo. Generation of a Gridded Bathymetry Dataset: Linear triangulation of the combined point files were done in MapInfo using the Vertical Mapper 2.0 partner product software. The resultant TIN file was then used to create a continuous grid file with 30 meter resolution on a UTM projection using a NAD27 horizontal datum. A second grid was created from the first by aggregating the 30 meter grid values to 90 meter resolution and exporting the 90m center points. A new TIN was created after reattaching the shoreline pts. The triangle side lengths and coincident point distances were small enough to disallow interpolation outside the 90m distance, so as to emulate a rectangular interpolation and still allow the shoreline to be represented without averaging out the values. The result of the new file is a geographic 3 arc second resolution grid. Both grids were cut to the estuary boundary shoreline. 7.5 minute and 1 degree sections were then created from these grids. The 7.5 minute grids have 30 meter resolution in a UTM projection using the NAD27 datum. The 1 degree grids have a 3 arc second resolution in a geographic projection (Latitude/Longitude) using the NAD27 datum. In their native form, both of these grids are in proprietary formats. Creating DEM files: The MapInfo grid files were converted to a public domain USGS format DEM files using the NOAA DEM maker software. The formats available for downloading are 30 meter and 3 arc second DEMs in USGS DEM format. DEMs are viewed on interactive editing systems to identify and correct blunder and systematic errors. DEMs are verified for physical format and logical consistency.
              1 2017-04-14T00:00:00 Original data files were converted to netCDF with GDAL transform utility.
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              MI_Operation

              none found
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              MI_Platform

              none found
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              MI_Instrument

              none found
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