St. Andrew/St. Simons Sounds, GA (S160) Bathymetric Digital Elevation Model (30 meter resolution) Derived From Source Hydrographic Survey Soundings Collected by NOAA | spatialRepresentationInfo|
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(MI_Metadata) fileIdentifier: gov.noaa.ngdc.mgg.dem:standrew_stsimons_sounds_s160_30m language: eng; USA characterSet: (MD_CharacterSetCode) utf8 hierarchyLevel: (MD_ScopeCode) dataset contact: (CI_ResponsibleParty) organisationName: NOAA National Centers for Environmental Information positionName: DEM Information contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: dem.info@noaa.gov role: (CI_RoleCode) pointOfContact dateStamp: 2018-06-14 metadataStandardName: ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data metadataStandardVersion: ISO 19115-2:2009(E) return to top spatialRepresentationInfo: (MD_Georectified) numberOfDimensions: 2 axisDimensionProperties: (MD_Dimension) dimensionName: (MD_DimensionNameTypeCode) column dimensionSize: 1064 resolution: Measure: 30.000000 axisDimensionProperties: (MD_Dimension) dimensionName: (MD_DimensionNameTypeCode) row dimensionSize: 1498 resolution: Measure: 30.000000 cellGeometry: (MD_CellGeometryCode) area transformationParameterAvailability: true checkPointAvailability: false pointInPixel: (MD_PixelOrientationCode) center return to top referenceSystemInfo: (MD_ReferenceSystem) referenceSystemIdentifier: (RS_Identifier) authority: (CI_Citation) title: Mean Lower Low Water depth alternateTitle: MLLW depth date: (CI_Date) date: 2012-08-10 dateType: (CI_DateTypeCode) revision citedResponsibleParty: (CI_ResponsibleParty) organisationName: (withheld) contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://epsg.org/crs_5866/MLLW-depth.html name: MLLW depth description: GML for Mean Lower Low Water vertical coordinate reference system (in meters) available from the epsg-registry. function: (CI_OnLineFunctionCode) information role: (CI_RoleCode) resourceProvider citedResponsibleParty: (CI_ResponsibleParty) organisationName: European Petroleum Survey Group contactInfo: (CI_Contact) onlineResource: (CI_OnlineResource) linkage: https://epsg.org/home.html name: European Petroleum Survey Group Geodetic Parameter Registry description: Registry that accesses the EPSG Geodetic Parameter Dataset, which is a structured dataset of Coordinate Reference Systems and Coordinate Transformations. function: (CI_OnLineFunctionCode) search role: (CI_RoleCode) publisher code: urn:ogc:def:crs:EPSG::5866 return to top referenceSystemInfo: (MD_ReferenceSystem) referenceSystemIdentifier: (RS_Identifier) code: 26917 codeSpace: EPSG version: 8.6.2 return to top identificationInfo: (MD_DataIdentification) citation: (CI_Citation) title: St. Andrew/St. Simons Sounds, GA (S160) Bathymetric Digital Elevation Model (30 meter resolution) Derived From Source Hydrographic Survey Soundings Collected by NOAA date: (CI_Date) date: 1998-06-06 dateType: (CI_DateTypeCode) publication edition: First citedResponsibleParty: (CI_ResponsibleParty) organisationName: NOAA's National Ocean Service, Special Projects (SP) contactInfo: (CI_Contact) address: (CI_Address) city: Silver Spring administrativeArea: MD role: (CI_RoleCode) publisher citedResponsibleParty: (CI_ResponsibleParty) organisationName: Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Special Projects (SP) role: (CI_RoleCode) originator presentationForm: (CI_PresentationFormCode) mapDigital otherCitationDetails: The NOAA NOS Special Projects Office was dissolved around 2013. NCEI is archiving and maintaining the Estuarine Bathymetry and questions should be forwarded to NCEI DEM info. abstract: Bathymetry for St. Andrew/St. Simons Sounds was derived from fifteen surveys containing 87,618 soundings. Two older, overlapping, less accurate surveys were omitted before tinning the data. The average separation between soundings was 44 meters. Fourteen of the surveys used dated from 1934 to 1937. The remaining survey, located in the northeast, dated from 1954. The total range of sounding data was 1.5 meters to -22.9 meters at mean low water. Mean high water values between 2.0 and 2.4 meters were assigned to the shoreline. Fifteen points were found that were not consistent with the surrounding data. These were removed prior to tinning. DEM grid values outside the shoreline (on land) were assigned null values (-32676). St. Andrew/St. Simons Sounds have ten 7.5 minute DEMs and two one degree DEMs. 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. purpose: Bathymetric DEM's can be used as layers in Geographic Information Systems (GIS) for earth science analysis. DEM's can also serve as tools for volumetric analysis, for site location of structures, or for drainage basin delineation. The source soundings are collected by the NOS Office of Coast Survey (OCS). status: (MD_ProgressCode) completed pointOfContact: (CI_ResponsibleParty) organisationName: NOAA National Centers for Environmental Information positionName: DEM Information contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: dem.info@noaa.gov role: (CI_RoleCode) pointOfContact resourceMaintenance: (MD_MaintenanceInformation) maintenanceAndUpdateFrequency: (MD_MaintenanceFrequencyCode) irregular descriptiveKeywords: (MD_Keywords) keyword: Earth Science > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography keyword: Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry keyword: Earth Science > Oceans > Bathymetry/Seafloor Topography > Water Depth keyword: Earth Science > Oceans > Coastal Processes > Coastal Elevation type: (MD_KeywordTypeCode) theme thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Science Keywords date: (unknown) descriptiveKeywords: (MD_Keywords) keyword: 1 meter - < 30 meters type: (MD_KeywordTypeCode) dataResolution thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Horizontal Data Resolution Keywords date: (unknown) descriptiveKeywords: (MD_Keywords) keyword: 1 meter - < 10 meters type: (MD_KeywordTypeCode) dataResolution thesaurusName: (CI_Citation) title: Global Change Master Directory (GCMD) Vertical Data Resolution Keywords date: (unknown) descriptiveKeywords: (MD_Keywords) keyword: Coastal Relief keyword: Gridded elevations keyword: Bathymetry type: (MD_KeywordTypeCode) theme thesaurusName: (CI_Citation) title: Uncontrolled date: (unknown) descriptiveKeywords: (MD_Keywords) keyword: St. Andrew/St. Simons Sounds, GA keyword: Georgia keyword: United States type: (MD_KeywordTypeCode) place thesaurusName: (CI_Citation) title: None date: (unknown) resourceConstraints: (MD_Constraints) useLimitation: 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. resourceConstraints: (MD_Constraints) useLimitation: Produced by the NOAA National Centers for Environmental Information. Not subject to copyright protection within the United States. resourceConstraints: (MD_LegalConstraints) accessConstraints: (MD_RestrictionCode) otherRestrictions otherConstraints: Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives. aggregationInfo: (MD_AggregateInformation) aggregateDataSetName: (CI_Citation) title: NOAA NOS Estuarine Bathymetry date: (CI_Date) date: 1999-01-01 dateType: (CI_DateTypeCode) publication citedResponsibleParty: (CI_ResponsibleParty) organisationName: National Oceanic and Atmospheric Administration(NOAA), National Ocean Service (NOS), Special Projects (SP) positionName: Chief, Integrated Planning and Technical Services contactInfo: (CI_Contact) phone: (CI_Telephone) voice: 301-713-3000 facsimile: 301-713-4384 address: (CI_Address) deliveryPoint: 1305 East West Highway N/MB7 city: Silver Spring administrativeArea: Maryland postalCode: 20910 electronicMailAddress: robert.wilson@noaa.gov role: (CI_RoleCode) originator citedResponsibleParty: (CI_ResponsibleParty) organisationName: National Oceanic and Atmospheric Administration(NOAA), National Ocean Service (NOS), Special Projects (SP) positionName: Chief, Integrated Planning and Technical Services contactInfo: (CI_Contact) phone: (CI_Telephone) voice: 301-713-3000 facsimile: 301-713-4384 address: (CI_Address) deliveryPoint: 1305 East West Highway N/MB7 city: Silver Spring administrativeArea: Maryland postalCode: 20910 electronicMailAddress: robert.wilson@noaa.gov role: (CI_RoleCode) publisher citedResponsibleParty: (CI_ResponsibleParty) organisationName: National Oceanic and Atmospheric Administration(NOAA), National Ocean Service (NOS), Special Projects (SP) positionName: Chief, Integrated Planning and Technical Services contactInfo: (CI_Contact) phone: (CI_Telephone) voice: 301-713-3000 facsimile: 301-713-4384 address: (CI_Address) deliveryPoint: 1305 East West Highway N/MB7 city: Silver Spring administrativeArea: Maryland postalCode: 20910 electronicMailAddress: robert.wilson@noaa.gov role: (CI_RoleCode) pointOfContact otherCitationDetails: The NOS Special Projects Office was dissolved around 2013. The Estuarine Bathymetry DEM products were assimilated by NCEI in 2016 for archive and redistribution. associationType: (DS_AssociationTypeCode) largerWorkCitation initiativeType: (DS_InitiativeTypeCode) campaign aggregationInfo: (MD_AggregateInformation) aggregateDataSetIdentifier: (MD_Identifier) code: S160 associationType: (DS_AssociationTypeCode) crossReference initiativeType: (DS_InitiativeTypeCode) collection spatialRepresentationType: (MD_SpatialRepresentationTypeCode) grid language: eng; USA characterSet: (MD_CharacterSetCode) utf8 topicCategory: (MD_TopicCategoryCode) oceans topicCategory: (MD_TopicCategoryCode) elevation extent: (EX_Extent) geographicElement: (EX_GeographicBoundingBox) extentTypeCode: true westBoundLongitude: -81.728279 eastBoundLongitude: -81.391337 southBoundLatitude: 30.859804 northBoundLatitude: 31.266734 temporalElement: (EX_TemporalExtent) extent: TimePeriod: beginPosition: 1934-01-01 endPosition: 1954-01-01 supplementalInformation: The datum for these bathymetric DEMs is not the same as that used by the United States Geological Survey (USGS) for land based DEMs which results in a discontinuity if the two datasets are merged together. Moreover, the shoreline for the USGS DEMs is indeterminate and not the same as that used for the Bathymetric DEMs. Because of these differences, extreme care should be used in merging NOAA and USGS DEM data. 7.5-minute DEMs have rows and columns which vary in length and are staggered. The UTM bounding coordinates form a quadrilateral (no two sides are parallel to each other), rather than a rectangle. The user will need to pad out the uneven rows and columns with blanks or flagged data values, if a rectangle is required for the user's application. Some software vendors have incorporated this function into their software for input of standard formatted USGS DEMs. The data within the bathymetry file is floating point. When using the data within a GIS care must be taken to ensure that the data are being read as floating point and not integer data. return to top contentInfo: (MD_ImageDescription) attributeDescription: (missing) contentType: (MD_CoverageContentTypeCode) image dimension: (MD_Band) descriptor: GDAL Band Number 1 bitsPerValue: 32 return to top contentInfo: (MD_FeatureCatalogueDescription) includedWithDataset: false featureCatalogueCitation: (unknown) (CI_Citation) title: Entity and Attribute Information date: (unknown) otherCitationDetails: Entity and Attribute Overview: The digital elevation model is composed of a elevation value linked to a grid cell location representing a gridded form of a bathymetric map overlay. Each grid cell entity contains a 6-character integer value between -32,767 and 32,768. The grid is generated from profiles of data each containing header information (profile identifier, starting point, relative datum for profile values (deepest value within the DEM), number of values, etc) followed by profile values relative to the relative datum for the profile. All non-null values in the profile are positive. Entity and Attribute Detail Citation: U.S. Department of the Interior, U.S. Geological Survey, 1992, Standards for digital elevation models: Reston, VA, is available at:http://rockyweb.cr.usgs.gov/nmpstds/demstds.html return to top distributionInfo: (MD_Distribution) distributionFormat: (MD_Format) name: netCDF version: 4 Classic distributor: (MD_Distributor) distributorContact: (CI_ResponsibleParty) organisationName: NOAA National Centers for Environmental Information positionName: DEM Information contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: dem.info@noaa.gov role: (CI_RoleCode) pointOfContact transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/thredds/fileServer/regional/standrew_stsimons_sounds_s160_30m.nc protocol: HTTPS name: Download NetCDF File description: Download NetCDF File function: (CI_OnLineFunctionCode) download transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/thredds/dodsC/regional/standrew_stsimons_sounds_s160_30m.nc.html protocol: OPeNDAP:OPeNDAP name: OPeNDAP Dataset Access Form description: OPeNDAP Dataset Access Form function: (CI_OnLineFunctionCode) download transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/thredds/wcs/regional/standrew_stsimons_sounds_s160_30m.nc?service=WCS&version=1.0.0&request=GetCapabilities protocol: OGC:WCS name: Web Coverage Service GetCapabilities description: Web Coverage Service GetCapabilities function: (CI_OnLineFunctionCode) information transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/thredds/wms/regional/standrew_stsimons_sounds_s160_30m.nc?service=WMS&version=1.3.0&request=GetCapabilities protocol: OGC:WMS name: Web Map Service GetCapabilities description: Web Map Service GetCapabilities function: (CI_OnLineFunctionCode) information transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/thredds/ncss/regional/standrew_stsimons_sounds_s160_30m.nc/dataset.html protocol: HTTPS name: Download a subset of the NetCDF description: Download a subset of the NetCDF function: (CI_OnLineFunctionCode) download transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/thredds/ncml/regional/standrew_stsimons_sounds_s160_30m.nc?catalog=https%3A%2F%2Fwww.ngdc.noaa.gov%2Fthredds%2Fcatalog%2Fregional%2Fcatalog.html&dataset=regionalDatasetScan%2Fstandrew_stsimons_sounds_s160_30m.nc protocol: HTTPS name: NetCDF Markup Language file description: NetCDF Markup Language file function: (CI_OnLineFunctionCode) information transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/mgg/bathymetry/estuarine protocol: HTTPS name: project web page description: text search function: (CI_OnLineFunctionCode) search transferOptions: (MD_DigitalTransferOptions) onLine: (CI_OnlineResource) linkage: https://www.ngdc.noaa.gov/mgg/bathymetry/estuarine protocol: HTTPS name: project web page description: map search function: (CI_OnLineFunctionCode) search return to top dataQualityInfo: (DQ_DataQuality) scope: (DQ_Scope) level: (MD_ScopeCode) dataset report: (DQ_AbsoluteExternalPositionalAccuracy) nameOfMeasure: Horizontal Positional Accuracy Report evaluationMethodDescription: The horizontal accuracy of the DEM is expressed as an estimated root mean square error (RMSE). The estimate of the RMSE is based upon horizontal accuracy tests of the source soundings used to generate the DEM. As a first approximation the locational accuracy of the source soundings are 0.0015 m at source "Smooth Sheet" scale (120 m @ 1:80,000 to 15 m @ 1:10,000). Smooth Sheets are maps generated as a principle product of each (historic) hydrographic survey with fully corrected soundings plotted on them. result: (missing) report: (DQ_AbsoluteExternalPositionalAccuracy) nameOfMeasure: Horizontal Positional Accuracy measureDescription: Digital elevation models comply with the National Map Accuracy Standards (NMAS) accuracy requirements. result: (DQ_QuantitativeResult) valueUnit: BaseUnit: identifier: meters unitsSystem: http://www.bipm.org/en/si/ value: Record: 3 meters (estimated) report: (DQ_AbsoluteExternalPositionalAccuracy) nameOfMeasure: Vertical Positional Accuracy Report evaluationMethodDescription: The vertical RMSE statistic is used to describe the vertical accuracy of a DEM. It encompasses both random and systematic errors introduced during production of the data. The RMSE is encoded in element number 5 of record C of the DEM. This accuracy estimate includes components related to quantization of the source soundings (1.3 to 0.15 m), the systematic editing of the source data (1percentor 0.10m), un-sampled bathymetric features (estimated at less than 5 percent of depth), time related changes (erosion, deposition, and seismic shifts), and dredging operations (cut and fill). It is estimated that the accuracy of the Bathymetric DEMs is 2 percent of depth or 1 meter for depths greater than 20 meters and 2 percent of depth or 0.20 meters for depths shallower than 20 meters. THESE DEMs SHOULD NOT BE USED FOR NAVIGATION. There are three types of DEM vertical errors: blunder, systematic, and random. These errors are reduced in magnitude by editing but cannot be completely eliminated. Blunders are errors of major proportions and are easily identified and removed during interactive editing. Systematic errors follow some fixed pattern and are introduced by data collection procedures and systems. Systematic error artifacts include vertical unsampled elevation shifts, relative spacing of the source soundings, misinterpretation of terrain surface caused by softness or poor reflectivity and by the resolution of the collected soundings (feet, feet and fractions, fathoms, fathoms and fractions, meters, tenths of meters etc.). Random errors result from unknown or accidental causes. The 1 degree (DSQ) DEMs are generated from 30 m grids on UTM projection. The RMSE difference between these surfaces is an estimate of the vertical accuracy of the DSQ DEMs. result: (missing) report: (DQ_CompletenessCommission) evaluationMethodDescription: The DEM is visually inspected for completeness on a DEM view and edit system for the purpose of performing a final quality control and if necessary, edit of the DEM. The physical format of each DEM is validated for content completeness and logical consistency during production quality control. Due to the variable orientation of the 7 1/2 minute quadrilateral in relation to the Universal Transverse Mercator (UTM) projection grid, profiles that pass within the bounds of the DEM quadrilateral may be void of elevation grid points and are not represented in the DEM. This condition occurs infrequently and is always the first or last profile of the dataset. DEMs may contain void areas caused by elevations being above Mean High Water or on non-tidal land. Void elevations are assigned the value of -32,767. In addition, suspect elevation areas may exist in the DEM but are not specifically identified. Only available data digitized before 1997 were used in this project. Additional sounding information may exist for areas which have holes in the bathymetric data set, but was not available at the time this project was completed. No additional updates or error corrections are planned for this data set. result: (unknown) report: (DQ_ConceptualConsistency) measureDescription: The fidelity of the relationships encoded in the data structure of the DEM are automatically verified using a NOAA-NOS software program upon completion of the data production cycle. The test verifies full compliance to the DEM specification. result: (unknown) lineage: (LI_Lineage) processStep: (LE_ProcessStep) description: 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. dateTime: (unknown) processStep: (LE_ProcessStep) description: Original data files were converted to netCDF with GDAL transform utility. dateTime: DateTime: 2017-04-14T00:00:00 processor: (CI_ResponsibleParty) organisationName: NOAA National Centers for Environmental Information positionName: DEM Information contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: dem.info@noaa.gov role: (CI_RoleCode) pointOfContact source: (LI_Source) description: Source Contribution: Hydrographic Soundings; Source Type: CD-ROM sourceCitation: (CI_Citation) title: National Ocean Service- Hydrographic Survey Data date: (CI_Date) date: 1997-01-01 dateType: (CI_DateTypeCode) publication citedResponsibleParty: (CI_ResponsibleParty) organisationName: NOAA, National Environmental Satellite, Data and Information Service (NESDIS), National Geophysical Data Center (NGDC) contactInfo: (CI_Contact) address: (CI_Address) city: Boulder administrativeArea: CO role: (CI_RoleCode) publisher citedResponsibleParty: (CI_ResponsibleParty) organisationName: National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Special Projects role: (CI_RoleCode) originator presentationForm: (CI_PresentationFormCode) mapDigital otherCitationDetails: Surveys Used in Bathymetry Processing - H05579, 1937; H05581, 1934; H05590, 1934; H05591, 1935; H05594, 1934; H05685, 1934; H05686, 1935; H05687, 1935; H05688, 1935; H05689, 1935; H05691, 1935; H05698, 1935; H05752, 1935; H05753, 1935; H08215, 1954ne sourceExtent: (EX_Extent) temporalElement: (EX_TemporalExtent) extent: TimePeriod: beginPosition: 1934-01-01 endPosition: 1954-01-01 source: (LI_Source) description: Source Contribution: Shoreline position; Source Type: CD-ROM sourceCitation: (CI_Citation) title: Medium Resolution Vector Shoreline date: (CI_Date) date: 1994-01-01 dateType: (CI_DateTypeCode) publication citedResponsibleParty: (CI_ResponsibleParty) organisationName: NOAA's Ocean Service contactInfo: (CI_Contact) address: (CI_Address) city: Boulder administrativeArea: CO role: (CI_RoleCode) publisher citedResponsibleParty: (CI_ResponsibleParty) organisationName: National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS) role: (CI_RoleCode) originator presentationForm: (CI_PresentationFormCode) mapDigital sourceExtent: (EX_Extent) temporalElement: (EX_TemporalExtent) extent: TimePeriod: beginPosition: 1970-01-01 endPosition: 1990-01-01 source: (LI_Source) description: Source Contribution: Ground control points; Source Type: magnetic tape sourceCitation: (CI_Citation) title: Project control date: (CI_Date) date: 1992-05-03 dateType: (CI_DateTypeCode) publication citedResponsibleParty: (CI_ResponsibleParty) organisationName: U.S. Geological Survey contactInfo: (CI_Contact) address: (CI_Address) city: Reston administrativeArea: VA role: (CI_RoleCode) publisher citedResponsibleParty: (CI_ResponsibleParty) organisationName: United States Geologic Survey (USGS) or NOAA's National Geodetic Survey (NGS) role: (CI_RoleCode) originator sourceExtent: (EX_Extent) temporalElement: (EX_TemporalExtent) extent: (unknown) return to top metadataMaintenance: (MD_MaintenanceInformation) maintenanceAndUpdateFrequency: (MD_MaintenanceFrequencyCode) annually maintenanceNote: This metadata was automatically generated from the FGDC Content Standards for Digital Geospatial Metadata standard (version FGDC-STD-001-1998 Generated by mp version 2.8.26 on Tue Jun 06 11:30:55 2006) using the 2012-07-27 version of the FGDC RSE to ISO 19115-2 transform for DEMs. maintenanceNote: Last Translation from FGDC 2018-02-23T12:10:09.378-07:00 contact: (CI_ResponsibleParty) organisationName: NOAA National Centers for Environmental Information positionName: DEM Information contactInfo: (CI_Contact) address: (CI_Address) electronicMailAddress: dem.info@noaa.gov role: (CI_RoleCode) pointOfContact |