Current Bathymetry Grid of Rhode Island
Metadata also available as
Metadata:
- Identification_Information:
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- Citation:
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- Citation_Information:
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- Originator: NOAA Coastal Services Center
- Publication_Date: 20010731
- Title: Current Bathymetry Grid of Rhode Island
- Edition: One
- Geospatial_Data_Presentation_Form: Map
- Publication_Information:
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- Publication_Place: Charleston, South Carolina, USA
- Publisher: NOAA Coastal Services Center
- Other_Citation_Details:
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This data layer was created from the Geophysical Data System
(GEODAS) data sets compiled by the National Geophysical Data Center
(NGDC) from NOAA hydrographic surveys.
- Larger_Work_Citation:
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- Citation_Information:
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- Originator: NOAA Coastal Services Center
- Publication_Date: 20010630
- Title: Rhode Island Habitat Restoration Portal
- Publication_Information:
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- Publication_Place: Charleston, South Carolina, USA
- Publisher: NOAA Coastal Services Center
- Online_Linkage: <http://www.csc.noaa.gov/lcr/rhodeisland>
- Description:
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- Abstract:
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The Bathymetry Grid of Rhode Island was created
for use in the Rhode Island Habitat Restoration Portal project.
Hydrographic survey data were imported into Environmental Systems Research
Institute (ESRI), Inc., ArcView geographic information system (GIS)
software for visualization. These data represent a composite of the
bathymetric information gathered through the National Ocean
Service hydrographic survey from Rhode Island waters from 1934 to 1996.
- Purpose:
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The data layer created from this dataset was used to delineate areas of
optimal depth for seagrass habitat. These areas were then overlaid with
other data to determine potential seagrass restoration sites.
- Supplemental_Information:
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Grid creation involved mathematical interpolation of values for some
cells in the data layer. These cell values were calculated
through the creation of a Triangulated Irregular Network (TIN) and a GRID
using the methods described in this document. Therefore, this
represents an estimate of the actual bathymetry of Rhode
Island waters. It is the user's responsibility to
determine the appropriate application of this data layer.
- Time_Period_of_Content:
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- Time_Period_Information:
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- Range_of_Dates/Times:
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- Beginning_Date: 1934
- Ending_Date: 1996
- Currentness_Reference: ground condition
- Status:
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- Progress: Complete
- Maintenance_and_Update_Frequency: None planned
- Spatial_Domain:
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- Bounding_Coordinates:
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- West_Bounding_Coordinate: -71.9002
- East_Bounding_Coordinate: -71.0950
- North_Bounding_Coordinate: 41.8738
- South_Bounding_Coordinate: 41.1154
- Keywords:
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- Theme:
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- Theme_Keyword_Thesaurus: None
- Theme_Keyword: Bathymetry
- Theme_Keyword: Bathymetric data
- Theme_Keyword: Depth
- Theme_Keyword: Geographic Information Systems
- Theme_Keyword: GIS
- Theme_Keyword: Grid
- Place:
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- Place_Keyword_Thesaurus: None
- Place_Keyword: Rhode Island
- Place_Keyword: Narragansett Bay
- Place_Keyword: Rhode Island Sound
- Place_Keyword: New England
- Place_Keyword: Northeast
- Access_Constraints: None
- Use_Constraints:
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It is the user's responsibility to determine the
appropriate use of this data layer.
- Point_of_Contact:
-
- Contact_Information:
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- Contact_Organization_Primary:
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- Contact_Organization: NOAA Coastal Services Center
- Contact_Position:
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Landscape Characterization and Restoration (LCR)
Program Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 2234 South Hobson Avenue
- City: Charleston
- State_or_Province: South Carolina
- Postal_Code: 29405
- Country: USA
- Contact_Voice_Telephone: 843-740-1200
- Contact_Facsimile_Telephone: 843-740-1224
- Contact_Electronic_Mail_Address: csc@csc.noaa.gov
- Hours_of_Service: Monday-Friday, 8am-5pm, Eastern Standard Time
- Native_Data_Set_Environment:
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ESRI Grid format
i:\lcr\rhode_island\web_prototype\gis\grids_e00\bathygridft
- Data_Quality_Information:
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- Attribute_Accuracy:
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- Attribute_Accuracy_Report:
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No formal tests were performed. The accuracy follows
the data accuracy of the Geophysical Data System for Hydrographic
Survey (GEODAS).
- Logical_Consistency_Report:
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The data were compared to Rhode Island state
land boundary data and found to exist within state waters.
- Completeness_Report:
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These data are believed to be complete within the area of
interest. In cases where multiple soundings occurred within 50 meters,
older soundings were discarded. The remaining data available from 1934-1996
surveys were included in layer creation.
- Positional_Accuracy:
-
- Horizontal_Positional_Accuracy:
-
- Horizontal_Positional_Accuracy_Report:
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The accuracy follows the data accuracy of the Geophysical Data System for Hydrographic
Survey (GEODAS). The data were retrieved from the GEODAS database with
latitude/longitude coordinates in decimal degrees
referenced to either the North American Datum of 1927 (NAD 27)
or 1983 (NAD 83). All data points referenced to NAD 27 were then
converted into NAD 83 using ArcView's Projection Utility Wizard extension
and projected into Rhode Island State Plane Feet.
- Vertical_Positional_Accuracy:
-
- Vertical_Positional_Accuracy_Report:
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The data were referenced to local datum of mean low water (MLW) or mean
lower low water (MLLW) at the time of collection, regardless of
collection year, depending on the survey.
- Lineage:
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- Source_Information:
-
- Source_Citation:
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- Citation_Information:
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- Originator:
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NOAA National Environmental Satellite, Data, and
Information Service (NESDIS)
- Publication_Date: 1998
- Title: Geophysical Data System (GEODAS) for Hydrographic Survey Data
- Edition: Volume 1, Version 4.0
- Geospatial_Data_Presentation_Form: tabular digital data
- Publication_Information:
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- Publication_Place: Boulder, Colorado
- Publisher:
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NOAA National Geophysical Data Centers (NGDC), Marine
Geology and Geophysics Division
- Online_Linkage: <http://www.ngdc.noaa.gov/mgg/>
- Type_of_Source_Media: CD-ROM
- Source_Time_Period_of_Content:
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- Time_Period_Information:
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- Range_of_Dates/Times:
-
- Beginning_Date: 1934
- Ending_Date: 1996
- Source_Currentness_Reference: ground condition
- Source_Citation_Abbreviation: NGDC
- Source_Contribution:
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The GEODAS CD-ROM contained the data and retrieval software
needed to create this data layer.
- Process_Step:
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- Process_Description:
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The data were retrieved from the CD-ROM using the default
HYD93 download and tabulated with header information. Data referenced to NAD 27
was separated from data referenced to NAD 83. The
data were saved as DBF files and brought into ArcView as
event themes. NAD 27 data were then converted from NAD 27 to NAD 83
using ArcView's Projection Utility Wizard extension and saved as a shapefile.
All data were projected into Rhode Island State Plane (feet) and then merged using
ArcView's Geoprocessing Wizard Utility.
- Source_Used_Citation_Abbreviation: NGDC
- Process_Date: 20010321
- Process_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: NOAA Coastal Services Center
- Contact_Position:
-
Landscape Characterization and Restoration Program (LCR)
Program Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 2234 South Hobson Avenue
- City: Charleston
- State_or_Province: South Carolina
- Postal_Code: 29405
- Country: USA
- Contact_Voice_Telephone: 843-740-1200
- Contact_Facsimile_Telephone: 843-740-1224
- Contact_Electronic_Mail_Address: csc@csc.noaa.gov
- Hours_of_Service: Monday-Friday, 8am-5pm, Eastern Standard Time
- Process_Step:
-
- Process_Description:
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CREATING A TIN
The shapefile was exported into a coverage using ArcCatalog. The point coverage
was converted to a TIN using ArcToolbox using the
"Create a tin" wizard with the following constraints: A hardclip area, using a
hull approximately the size of the bathymetric point footprint confined the
processing area. Weed tolerance was set to 200; z-value = 1.
The hull (footprint) was created by taking the ribay.shp file
(<http://www.edc.uri.edu/rigis-spf/statewide/state.html#boundaries>) and
stretching four of the southernmost vertices to contain all of the bathymetric
points. This shapefile was then exported to a coverage in ArcInfo workstation
using the SHAPEARC command (default options) and then building for polygons.
"Hard erase" areas were created from boundaries available from the
above Web site (statline.shp). The land area was created from the statline.shp
file by converting that file to a coverage in ArcCatalog. The islands were
created by taking the ribay.shp file and selecting all the polygons that were
not equal to water, converting that subset to a shapefile in ArcView, exporting
that new shapefile to a coverage in workstation ArcInfo using the SHAPEARC
command (default options), and then BUILDing for polygons. Weed tolerance
was set to 200; z-value = 1. The proximal tolerance was set to 10 with a z-factor of 1.
CREATING A GRID
Using ArcToolbox, the tin was converted to a grid using the "Import tin to grid"
tool. Cell size was set to 50 (feet). Using ArcView, Analysis Properties/
Analysis Extent was set to the original point coverage with a cell size set
as "current value." Map calcultor was employed to multiply the existing grid
by 1. This removed some of the edges from the grid, which were of questionable
accuracy because of the way that TIN handles edges. The new map calculation
was saved (convert to grid). A new grid representing soundings in feet was
calculated using the Map Calculator and a conversion factor of 3.280839895013123.
- Source_Used_Citation_Abbreviation: NGDC
- Process_Date: 20010410
- Process_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: NOAA Coastal Services Center
- Contact_Position:
-
Landscape Characterization and Restoration Program (LCR)
Program Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 2234 South Hobson Avenue
- City: Charleston
- State_or_Province: South Carolina
- Postal_Code: 29405
- Country: USA
- Contact_Voice_Telephone: 843-740-1200
- Contact_Facsimile_Telephone: 843-740-1224
- Contact_Electronic_Mail_Address: csc@csc.noaa.gov
- Hours_of_Service: Monday-Friday, 8am-5pm, Eastern Standard Time
- Spatial_Data_Organization_Information:
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- Direct_Spatial_Reference_Method: Raster
- Raster_Object_Information:
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- Raster_Object_Type: Grid Cell
- Row_Count: 5527
- Column_Count: 4386
- Spatial_Reference_Information:
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- Horizontal_Coordinate_System_Definition:
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- Planar:
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- Grid_Coordinate_System:
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- Grid_Coordinate_System_Name: State Plane Coordinate System 1983
- State_Plane_Coordinate_System:
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- SPCS_Zone_Identifier: Rhode Island
- Transverse_Mercator:
-
- Scale_Factor_at_Central_Meridian: 0.999994
- Longitude_of_Central_Meridian: -71.500000
- Latitude_of_Projection_Origin: 41.083333
- False_Easting: 328083.333300
- False_Northing: 0.000000
- Planar_Coordinate_Information:
-
- Planar_Coordinate_Encoding_Method: Row and column
- Coordinate_Representation:
-
- Abscissa_Resolution:
- Ordinate_Resolution:
- Planar_Distance_Units: Feet
- Geodetic_Model:
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- Horizontal_Datum_Name: North American Datum of 1983
- Ellipsoid_Name: Geodetic Reference System 80
- Semi-major_Axis: 20925604.4720406
- Denominator_of_Flattening_Ratio: 298.26
- Entity_and_Attribute_Information:
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- Detailed_Description:
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- Entity_Type:
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- Entity_Type_Label: ArcView Grid
- Entity_Type_Definition: raster grid produced by ArcView Spatial Analyst
- Entity_Type_Definition_Source: ESRI
- Overview_Description:
-
- Entity_and_Attribute_Overview:
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This data layer is a floating point grid, and therefore it
does not have an attribute table or set of attributes. The
cell value ranges are based on calculated depths in feet,
and negative values represent elevation while positive
values represent depth.
- Entity_and_Attribute_Detail_Citation: none
- Distribution_Information:
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- Distributor:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: NOAA Coastal Services Center
- Contact_Position: Clearinghouse Manager
- Contact_Address:
-
- Address_Type: mailing and physical address
- Address: 2234 South Hobson Avenue
- City: Charleston
- State_or_Province: South Carolina
- Postal_Code: 29405
- Country: USA
- Contact_Voice_Telephone: 843-740-1210
- Contact_Facsimile_Telephone: 843-740-1224
- Contact_Electronic_Mail_Address: csc@csc.noaa.gov
- Hours_of_Service: Monday-Friday, 8am-5pm, Eastern Standard Time
- Resource_Description: Bathymetry Grid of Rhode Island
- Distribution_Liability:
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While every effort has been made to ensure that these data
are accurate and reliable within limits of the state of the
art, NOAA will not assume any liability for damages caused
by any inaccuracies in these data, or failure in their use.
- Metadata_Reference_Information:
-
- Metadata_Date: 20010718
- Metadata_Review_Date:
- Metadata_Contact:
-
- Contact_Information:
-
- Contact_Organization_Primary:
-
- Contact_Organization: NOAA Coastal Services Center
- Contact_Position: Metadata Specialist
- Contact_Address:
-
- Address_Type: Mailing and physical address
- Address: 2234 South Hobson Avenue
- City: Charleston
- State_or_Province: South Carolina
- Postal_Code: 29405
- Country: USA
- Contact_Voice_Telephone: 843-740-1200
- Contact_Facsimile_Telephone: 843-740-1224
- Contact_Electronic_Mail_Address: csc@csc.noaa.gov
- Hours_of_Service: Monday-Friday, 8am-5pm, Eastern Standard Time
- Metadata_Standard_Name: FGDC CSDGM
- Metadata_Standard_Version: FGDC-STD-001-1998
Generated by mp version 2.7.27 on Wed May 22 09:25:57 2002