Current Bathymetry Grid of Rhode Island

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: NOAA Coastal Services Center
Publication_Date: 20010731
Title: Current Bathymetry Grid of Rhode Island
Edition: One
Geospatial_Data_Presentation_Form: Map
Publication_Information:
Publication_Place: Charleston, South Carolina, USA
Publisher: NOAA Coastal Services Center
Other_Citation_Details:
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:
Citation_Information:
Originator: NOAA Coastal Services Center
Publication_Date: 20010630
Title: Rhode Island Habitat Restoration Portal
Publication_Information:
Publication_Place: Charleston, South Carolina, USA
Publisher: NOAA Coastal Services Center
Online_Linkage: <http://www.csc.noaa.gov/lcr/rhodeisland>
Description:
Abstract:
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:
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:
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:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1934
Ending_Date: 1996
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -71.9002
East_Bounding_Coordinate: -71.0950
North_Bounding_Coordinate: 41.8738
South_Bounding_Coordinate: 41.1154
Keywords:
Theme:
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:
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:
It is the user's responsibility to determine the appropriate use of this data layer.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: NOAA Coastal Services Center
Contact_Position:
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:
ESRI Grid format i:\lcr\rhode_island\web_prototype\gis\grids_e00\bathygridm

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
No formal tests were performed. The accuracy follows the data accuracy of the Geophysical Data System for Hydrographic Survey (GEODAS).
Logical_Consistency_Report:
The data were compared to Rhode Island state land boundary data and found to exist within state waters.
Completeness_Report:
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:
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:
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:
Source_Information:
Source_Citation:
Citation_Information:
Originator:
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:
Publication_Place: Boulder, Colorado
Publisher:
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:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 1934
Ending_Date: 1996
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: NGDC
Source_Contribution:
The GEODAS CD-ROM contained the data and retrieval software needed to create this data layer.
Process_Step:
Process_Description:
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:
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).
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:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 5527
Column_Count: 4386


Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
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:
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:
Detailed_Description:
Entity_Type:
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:
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 METERS, and negative values represent elevation while positive values represent depth.
Entity_and_Attribute_Detail_Citation: none


Distribution_Information:
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:
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 09:24:30 2002