The Long Island Sound Submerged Cable and Pipeline Areas layer is a polygon feature-based layer that includes the location of submerged cable and/or pipeline areas in Long Island Sound. These can include, but are not necessarily limited to: electric transmission lines, telephone and/or fiber optic cables, natural gas and/or petroleum pipelines, etc. The layer is based on information from the 2002 edition of digital National Oceanic & Atmospheric Administration (NOAA) nautical charts provided by Maptech, Inc., a field survey completed by Ocean Surveys Inc (OSI) in 2002, and the *proposed* location of a pipeline from plans provided by Broadwater Energy in 2005. The Long Island Sound Submerged Cable and Pipeline Areas layer was originally created during the summer of 2002. The layer represents conditions at particular points in time. The layer includes representations of areas of underwater cables and/or pipelines. It does not include cable and/or pipeline areas landward of mean high water, nor does it include all possible submerged cables, pipelines, or other similar features. Features are polygon locations that represent the approximate or assumed location of cables and/or pipelines for the purpose of cartographic representation and general planning. Attribute information is comprised of codes to uniquely identify individual features, encode cable/pipeline type of information, and cartographically represent (symbolize) cable/pipeline features on a map. Data is compiled at 1:20,000 and 1:24,000 scale. This data is not planned for regular updates. Last updated 10/4/2005
The Long Island Sound Submerged Cable and Pipeline Areas layer is no better than 1:20,000-scale data. It depicts the location of submerged cable and/or pipeline areas. Use this layer to display the locations of underwater infrastructure within Long Island Sound and the waterways of Connecticut. Use this layer with 1:20,000-scale map data such as the 2002 digital National Oceanic & Atmospheric Administration (NOAA) Nautical Charts or with other 1:24,000 scale DEP data. Not intended for maps printed at map scales greater or more detailed than 1:20,000 scale.
For additional information, refer to the websites of the National Oceanic & Atmospheric Administration (NOAA) at www.noaa.gov, or Maptech, Inc. at www.maptech.com.
publication date
No restrictions or legal prerequisites for using the data. The data is suitable for use at appropriate scale, and is not intended for maps printed at scales greater or more detailed than 1:20,000 scale. Although this data set has been used by the State of Connecticut, Department of Environmental Protection, no warranty, expressed or implied, is made by the State of Connecticut, Department of Environmental Protection as to the accuracy of the data and or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the State of Connecticut, Department of Environmental Protection in the use of these data or related materials. The user assumes the entire risk related to the use of these data. Once the data is distributed to the user, modifications made to the data by the user should be noted in the metadata. When printing this data on a map or using it in a software application, analysis, or report, please acknowledge the State of Connecticut, Department of Environmental Protection, the National Oceanic & Atmospheric Administration (NOAA), and Maptech, Inc. as the sources for this information. DATA IS NOT SUITABLE FOR NAVIGATION.
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The Long Island Sound Submerged Cable and Pipeline Areas layer retains the feature types and information identified by the State of Connecticut, Department of Environmental Protection and obtained from the 2002 edition of the digital National Oceanic & Atmospheric Administration (NOAA) Nautical Charts provided by Maptech, Inc., a 2002 field survey by Ocean Surveys Inc., and plans provided to the State of Connecticut, Department of Environmental Protection by Broadwater Energy dated 9/26/2005. All attributes have valid values. Values are within defined domains. The accuracy test for the KEY_COD attribute values was conducted by comparing the information presented in the source data with interactive displays of the data on a computer graphic system. These computer displays depicted and labeled The Long Island Sound Submerged Cable and Pipeline Areas layer features in different colors based on KEY_COD values for comparison with the original data source. KEY_DECODE is the English language equivalent of (decodes) the KEY_COD field values. AV_LEGEND and IMS_LEGEND are broad classifications of Long Island Sound Submerged Cable and Pipeline Areas features. Long Island Sound Submerged Cable and Pipeline Areas features were manually selected and populated with KEY_COD attributes values to (uniquely) identify and describe individual features.
Polygon features conform to the following topological rules. Polygons are single part. There are no duplicate polygons. Polygons do not self overlap. Polygons do not overlap other polygons.
The completeness of the data reflects the feature content of the data sources, which include the 2002 edition of the digital National Oceanic & Atmospheric Administration (NOAA) Nautical Charts provided by Maptech, Inc., a 2002 field survey conducted by Ocean Surveys Inc., and plans provided to the State of Connecticut, Department of Environmental Protection by Broadwater Energy dated 9/26/2005. The Long Island Sound Submerged Cable and Pipeline Areas layer is complete in the sense that it accurately reflects the contents of the information available at the time the State of Connecticut, Department of Environmental Protection created the layer. However, compared to more recent information available today or current conditions, the Long Island Sound Submerged Cable and Pipeline Areas layer may be incomplete. This data is not planned for regular updates - for information on the latest Long Island Sound Submerged Cable and Pipeline Areas layer, please contact the State of Connecticut, Department of Environmental Protection point of contact.
The horizontal positional accuracy of this data is unknown.
The 2002 National Oceanic & Atmospheric Administration (NOAA) Digital Nautical Charts, once reprojected from their native *.bsb format in decimal degrees into *.tiff files in Connecticut State Plane Coordinates, NAD83, were used as the reference and data source from which the Long Island Sound Submerged Cable and Pipeline Areas layer features were digitzed.
This data consisted of GPS data from May 16 - May 28 2002. It was collected via shipborne GPS (system & type unknown) while the cable was being installed. Data was provided to the State of Connecticut, Department of Environmental, Office of Long Island Sound Programs by OSI.
A temporary polygon feature layer derived from GPS data, used to approximate the location of the Cross Sound Cable in New Haven Harbor for cartogrpahic representation. This polygon was added to the existing Long Island Sound Submerged Cable and Pipeline Areas layer.
The Long Island Sound Submerged Cable and Pipeline Areas layer is a 1:20,000-scale, polygon feature-based layer that includes the location of submerged cable and/or pipeline areas in Long Island Sound. These can include, but are not necessarily limited to: electric transmission lines, telephone and/or fiber optic cables, natural gas and/or petroleum pipelines, etc. Originally published in 2002, this layer is periodically modifed, and different versions have been and may be published over time. Changes made to the entire layer are reflected in the metadata process steps where this source, Source 4 - Long Island Sound Submerged Cable and Pipeline Areas layer, is cited as both the Source Used and Source Produced.
Plans provided coordinates for linear feature of proposed pipeline.
Linear feature created from points data entered from plans
Buffer of Source 6 for use in adding into Source 4.
Feature digitizing and attribution (heads up digitizing method) - Using ESRI ArcView 3 software, cable and pipeline features appearing on the National Oceanic & Atmospheric Administration (NOAA) 2002 digital charts were manually digitized on the screen (heads-up digitizing) at display scales greater than 1:20,000. Individual features represent polygon areas designated and noted as cable and or pipeline areas. Features were assigned attribute values based on information shown on the digital charts (i.e, cable and or pipeline area.) Feature location and attribute accuracy was visually checked and inspected by symbolizing and labeling features according to attribute value on the computer screen.
Attribute enhancements - KEY_DECODE and AV_LEGEND attributes were changed from storing abbreviated values in upper case to full length values in both upper and lower case. Additionally the IMS_LEGEND attribute was added to establish a very general classification scheme for symbolizing features with Internet mapping software environments such as ArcIMS.
Feature conversion & creation - Using ESRI ArcView 3 software, features from the source data set were imported as event tables for each days data. These were then converted to point shapefiles and then merged together into a single point shapefile. This composite shapefile was then reprojected from decimal degrees into CT State Plane Coordinates, NAD 83 using the ArcView 3 projection utility. Feature location accuracy was visually checked and inspected by displaying the points shapefile data over the National Oceanic & Atmospheric Administration (NOAA) digital chart data on the computer screen and making sure they fell within the harbor channel and terminated near to Shoreham, NY. Using a freeware version of the ArcView 3 XTools extension available at the ArcScripts download at the ESRIS web site (www.esri.com), these points were converted to a line feature based layer and then buffered by an arbitrary distance to create a simple polygon representation, 20 feet wide, that approximates the location of the cable.
Feature loading - The temp OSI data layer (polygon created from the GPS point data) was loaded into the existing Long Island Sound Submerged Cable and Pipeline Areas layer that was digitized from the National Oceanic & Atmospheric Administration (NOAA) digital Nautical Charts and described in the previous process steps.
Feature Creation - Created a linear feature class based on coordinates (UTM Zone 18N, feet, NAD 83) described on plans provided by Broadwater Energy dated 9/26/2005. Points were added via noted X,Y values. Where needed, fillets were added at the appropriate coordinates with the noted radius. Upon completion data was reprojected into Connecticut State Plane Coordinates, NAD 83 feet.
Buffering - the linear feature noted as Source 6 was buffered to create a polygon representation of the pipeline at the noted 30" width.
Feature copy and attribution - the polygon representation of the pipeline from Source 7 was copied into the final dataset (source 4). Attributes were updated to properly define and code the new feature
Dataset copied.
Internal feature number.
ESRI
Feature geometry.
ESRI
Text field identifying the chart/plans used to create the feature
State of Connecticut, Department of Environmental Protection
ArcView Legend. A text field for symbolizing different feature types on a map
State of Connecticut, Department of Environmental Protection
This category includes KEY_COD value 1
This category includes KEY_COD value 2
This category includes KEY_COD value 3
Text field giving the general name of the major waterbody the feature is in
State of Connecticut, Department of Environmental Protection
Text field identifying the data source for the feature
State of Connecticut, Department of Environmental Protection
data taken from 2002 NOAA Digital Nautical Charts
data taken from an Ocean Survey, Inc., survey cruise May, 2002
Broadwater Energy Plans
Text field providing, where available, the common name of a feature
State of Connecticut, Department of Environmental Protection
Internet Mapping Software Legend. A text file dfor classifying and symbolizing feature types in a simple manner for an Internet map.
State of Connecticut, Department of Environmental Protection
This category includes KEY_COD values 1, 2, & 3
Calculated length of feature in miles. Note, LENGTH_MI values are not automatically updated after modifying feature geometry (shape). Values must be recalculated after features are edited, simplified, generalized, clipped, dissolved, etc. Only calculated for certain features of negligible width
State of Connecticut, Department of Environmental Protection
Calculated area of polygon feature in acres. Note, ACREAGE values are not automatically updated after modifying feature geometry (shape). Values must be recalculated after features are edited, simplified, generalized, clipped, dissolved, etc.
State of Connecticut, Department of Environmental Protection
Type Code. Numeric values that classify different types of features.
State of Connecticut, Department of Environmental Protection
submerged cable areas
submerged pipeline areas
submerged cable and pipeline area
Type. Text values that correspond to numeric KEY_COD attribute values. KEY_CODE is the English equivalent of (decodes) the KEY_CODE field.
State of Connecticut, Department of Environmental Protection
Feature geometry.
ESRI
Calculated area of polygon feature in square miles. Note, AREA_SQMI values are not automatically updated after modifying feature geometry (shape). Values must be recalculated after features are edited, simplified, generalized, clipped, dissolved, etc.
State of Connecticut, Department of Environmental Protection
Includes Long Island Sound Submerged Cable and Pipeline Areas layer features such as submerged cables and pipelines. Information encoded about these features includes type, names, and measurement information and standard cartographic symbology classification schemes. Use the KEY_COD to uniquely identify features. Use the AV_LEGEND attribute to symbolize features by type on a map. Use the IMS_LEGEND attribute to more generally symbolize the features by type. Use the NAME attribute to label features on a map. To define a layer that only includes a certain type of feature, query Long Island Sound Submerged Cable and Pipeline Areas layer features for KEY_DECODE value equal to either "submerged cable area" OR "submerged cable/pipeline area" OR "submerged pipeline area"
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The data distributor does not provide custom GIS analysis or mapping services. Data is available in a standard format and may be converted to other formats, projections, coordinate systems, or selected for specific geographic regions by the party receiving the data.
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