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Connecticut State Line

Frequently-asked questions:


What does this data set describe?

Title:
Connecticut State Line

Abstract:
Connecticut State Line includes the line features of a layer named Connecticut. Connecticut is a 1:24,000-scale, polygon and line feature-based layer that depicts the geographic area encompassed by and the boundary for the State of Connecticut. The State of Connecticut is represented as one polygon feature surrounded by linear boundary features. The layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 and latitude and longitude coordinates that define the boundary between the states of Connecticut and New York in Long Island Sound. Feature length and geographic area are encoded for linear and polygon features, respectively. This layer was originally published in 1994.

Supplemental information:
In 2004, the State of Connecticut, Department of Environmental Protection developed automated procedures to maintaining feature topology and attribute integrity for the Town Master from USGS layer and layers derived from the Town Master from USGS layer such as the Connecticut layer. Using ArcInfo Workstation 8.3 software and Arc Macro Language (AML) scripting environment, the automated procedures were recorded in an AML file named MAKECOVER.AML for the political boundary category of data published by the State of Connecticut, Department of Environmental Protection. The MAKECOVER.AML maintains the features and feature attribute data for the Town Master from USGS, Town Master, Town, Connecticut, and Connecticut Mainland layers. For additional information related to the original source of data from the U.S. Geological Survey, refer to the Data User Guides and Standards for 1:24,000-Scale Digital Line Graphs and Quadrangle Maps available from the U.S. Geological Survey, National Mapping Program.

  1. How should this data set be cited?

    State of Connecticut, Department of Environmental Protection (data editor and publisher), U.S. Geological Survey, National Mapping Program (data compiler), 19940101, Connecticut State Line: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Other citation details:
    The USGS is the collector of the data (compiler). The State of Connecticut, Department of Environmental Protection is the creator and maintainer of the data layer (editor) and producer (publisher) of this information for use. The 2005 Edition includes the same set of geographic features published in 1994. This layer includes information that is static and does not change over time. This data is not updated. Data compiled at 1:24,000 scale.

  2. What geographic area does the data set cover?

    Bounding coordinates:
    West: -73.742172
    East: -71.781365
    North: 42.052612
    South: 40.949970

  3. What does it look like?

    http://www.cteco.uconn.edu/metadata/dep/browsegraphic/connecticutstate.gif (GIF)
    Full view of Connecticut State polygon and line features

  4. Does the data set describe conditions during a particular time period?

    Beginning date: 1969
    Ending date: 1984
    Currentness reference:
    Publication dates of the USGS 7.5 minute topographic quadrangle maps for the State of Connecticut through 1984.

  5. What is the general form of this data set?

    Geospatial data presentation form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      Indirect spatial reference:
      State of Connecticut, United States of America

      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • String (4)

    2. What coordinate system is used to represent geographic features?

      The map projection used is Lambert Conformal Conic.

      Projection parameters:
      Lambert Conformal Conic
      Standard parallel: 41.200000
      Standard parallel: 41.866667
      Longitude of central meridian: -72.750000
      Latitude of projection origin: 40.833333
      False easting: 999999.999996
      False northing: 499999.999998

      Planar coordinates are encoded using coordinate pair.
      Abscissae (x-coordinates) are specified to the nearest 0.000250.
      Ordinates (y-coordinates) are specified to the nearest 0.000250.
      Planar coordinates are specified in survey feet.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

      Vertical coordinate system definition:
      Altitude system definition:
      Altitude resolution: 1.000000
      Altitude encoding method: Explicit elevation coordinate included with horizontal coordinates

  7. How does the data set describe geographic features?

    Connecticut State Line
    Includes line features representing the Connecticut state boundary (Source: State of Connecticut, Department of Environmental Protection and U.S. Geological Survey, National Mapping Program)

    OBJECTID
    Internal feature number. (Source: ESRI)
                      

    Sequential unique whole numbers that are automatically generated.

    SHAPE
    Feature geometry. (Source: ESRI)
                      

    Coordinates defining the features.

    AV_LEGEND
    ArcView Legend. A text field for symbolizing different feature types on a map. (Source: State of Connecticut, Department of Environmental Protection and U.S. Geological Survey, National Mapping Program)
                      

    ValueDefinition
    State Boundary
    State boundary on the land between CT, NY, MA, and RI
    State Boundary Offshore
    State Boundary in the waters of Long Island Sound and Fishers Island Sound between CT, NY and RI.

    LENGTH_MI
    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. (Source: State of Connecticut, Department of Environmental Protection)
                      

    Numeric value

    SHAPE.len
    Entity and attribute overview:
    The Connecticut layer includes polygonal and linear features for the state of Connecticut boundary as published on the U.S. Geological Survey 7.5 minute topographic quadrangle maps. Polygon and line features primarily represent the geographic area for the State of Connecticut and its boundary, repectively. Information encoded about features includes standard symbology classification schemes, feature area in acres and square miles, and feature length in miles. Use the AV_LEGEND attribute to symbolize line features by type.

    Entity and attribute detail citation:
    For additional information related to the original source of data from the U.S. Geological Survey, refer to the Data User Guides and Standards for 1:24,000-Scale Digital Line Graphs and Quadrangle Maps available from the U.S. Geological Survey, National Mapping Program.
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Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)


  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    Howie Sternberg
    State of Connecticut, Department of Environmental Protection
    79 Elm Street
    Hartford, Connecticut 06106-5127
    USA

    860-424-3540 (voice)
    860-424-4058 (FAX)
    dep.gisdata@ct.gov
    Hours of Service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time
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Why was the data set created?

Connecticut is 1:24,000-scale base map data. For base map purposes, use this layer with other 1:24,000-scale base map data such as Town, Hydrography, Waterbody, Named Waterbody, Roads and Trails, Railroads, and Airports. All of these layers include information for Connecticut. Use the Connecticut layer as a backgound layer to cartographically distinguish the geographic are of Connecticut. When geoprocessing other 1:24,000 scale layers, use the Connecticut layer to clip features to the state of Connecticut region. Connecticut may be used as a possible data source for other 1:24,000-scale layers having features that should coincide with the Connecticut State boundary shown on USGS topographic quadrangle maps. Not intended for maps printed at map scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet.)

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How was the data set created?

  1. Where did the data come from?

    Source 1 - Town Master from USGS (source 1 of 4)

    State of Connecticut, Department of Environmental Protection (data editor and publisher), U.S. Geological Survey, National Mapping Program (data compiler), 19940101, Connecticut Town Master from USGS layer: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Type of source media: disc
    Source scale denominator: 24000
    Source contribution:
    Town Master from USGS is a 1:24,000-scale, polygon and line feature-based layer that includes all political boundary features depicted on all of the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps that cover the State of Connecticut. Line features include State, county, town (municipal), and borough boundaries. Polygon features depict the geographic areas for individual towns (municipalities) and cities and boroughs within individual towns. This layer is the primary data source for a set of political boundary layers published by the State of Connecticut, Department of Environmental Protection. The Town Master, Town, Connecticut, and Connecticut Mainland layers are all ultimately derived from the polygon and line features of the Town Master from USGS layer. Note, the town boundary between Middletown and Portand was corrected and changed from its location, as depicted on the USGS topographic quadrangle maps, from along the banks of the Connecticut River in Portand to the middle of the Connecticut River south of Wilcox Island to the Pecausett Meadows area in Portland. Additionally, coastline and island feature information from the Hydrography Master layer was incorporated into the Town Master from USGS layer in order to enclose the land areas encompassed by towns adjacent to Long Island Sound and to define the islands that are part of these coastal towns. Features derived from the Hydrography Master layer are attributed with specific COASTA_COD and COASTP_COD values. Town Master from USGS is in ArcInfo Coverage format.

    Source 2 - Connecticut (source 2 of 4)

    State of Connecticut, Department of Environmental Protection (data editor and publisher), U.S. Geological Survey, National Mapping Program (data compiler), 19940101, Connecticut State: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Type of source media: disc
    Source scale denominator: 24000
    Source contribution:
    Connecticut is in ArcInfo Coverage format.

    Source 3 - Connecticut_Line.shp (source 3 of 4)

    State of Connecticut, Department of Environmental Protection (data editor and publisher), U.S. Geological Survey, National Mapping Program (data compiler), 19940101, Connecticut State Line: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Type of source media: disc
    Source scale denominator: 24000
    Source contribution:
    A line feature-based layer that depicts the boundary for the State of Connecticut. Connecticut_Line.shp is in Shapefile format.

    Source 4 - Connecticut_State_Line (source 4 of 4)

    State of Connecticut, Department of Environmental Protection (data editor and publisher), U.S. Geological Survey, National Mapping Program (data compiler), 19940101, Connecticut State Line: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Type of source media: disc
    Source scale denominator: 24000
    Source contribution:
    A line feature-based layer that depicts the boundary for the State of Connecticut. Connecticut_State_Line is in GeoDatabase Feature Class format.

  2. What changes have been made?

    Date: 2005 (change 1 of 3)
    Create Connecticut layer - The State of Connecticut, Department of Environmental Protection developed an automated procedure to maintain feature topology and attribute integrity for the Connecticut layer by creating (deriving) the layer from a layer named Town Master from USGS. This procedure is documented in an Arc Macro Language (AML) script named MAKECOVER.AML for the political boundary category of data for the State of Connecticut, Department of Environmental Protection. This procedure combined the geometry of certain features and ensured consistent attribute values by programmatically joining lookup data tables to decode numeric code fields. The MAKECOVER.AML creates the Connecticut layer by extracting and processing features from the Town Master from USGS layer. All polygon and line features from the Town Master from USGS layer that defined boundaries in Connecticut were extracted and output to a separate ArcInfo Coverage named CONN. Subsequently, the TBPOLY_COD, TOWN_POLY, IMS_LEGEND, COASTP_COD, COAST_POLY, STATE_COD, FIPS_COD, TOWN_NO, TOWN, CNTY_COD, COUNTY, CONN_CITY, CONN_BORO polygon attributes and TBARC_COD, TOWN_ARC, COASTA_COD, COAST_ARC, STATE_COD, STATE_FLG, FIPS_FLG, CONN_FLG, TOWN_FLG, CITY_FLG, BORO_FLG, TNO_LEFT, TOWN_LEFT, TNO_RIGHT, TOWN_RIGHT, CITY_LEFT, CITY_RIGHT and BOROUGH line attributes were removed and polygon features were dissolved, merging all adjacent polygon features into a single polygon feature representing the state of Connecticut. The MAKECOVER.AML was executed in 2005 in order to derive the Connecticut layer from the 2005 Edition of the Town Master from USGS layer. The name of the resulting ArcInfo coverage created by this automated process is CONN.
    
    Note, all information is based on boundary lines depicted on USGS topographic quadrangle maps with the exception of most of the state boundary in Long Island Sound. The boundary line between the states of Connecticut and New York is described in Special Laws of Connecticut, Volume 16, pages 1104-1108, Senate Bill #322, An Act Establishing The Boundary Line Between Connecticut and New York. This Special Act documents the latitude and longitude coordinates of the state boundary monuments on the ground and points in the waters of Long Island Sound. These geodetic positions are based on Clark's spheroid of 1866 and are in degrees, minutes and seconds (DMS). The following boundary points enumerated in this act were used to define the state boundary in Long Island Sound.
    
    Point No. 170: Latitude 40 57 03.228, Longitude -73 36 46.418
    Point No. 171: Latitude 41 15 31.321, Longitude -72 05 24.685
    Point No. 172: Latitude 41 17 26.341, Longitude -72 01 10.937
    Point No. 173: Latitude 41 18 37.835, Longitude -71 55 47.626
    Point No. 174: Latitude 41 18 16.249, Longitude -71 54 28.477

    Person responsible for change:
    Howie Sternberg
    State of Connecticut, Department of Environmental Protection
    79 Elm Street
    Hartford, Connecticut 06106
    USA

    860-424-3540 (voice)

    Data sources used in this process:
    • Source 1 - Town Master from USGS

    Data sources produced in this process:
    • Source 2 - Connecticut

    Date: 2005 (change 2 of 3)
    Export to Shapefile format - Converted line feature data from an ArcInfo coverage named CONN to a Shapefile named Connecticut_Line.shp. Excluded the FNODE#, TNODE#, LPOLY#, RPOLY#, LENGTH, CONN#, and CONN-ID attributes from the Shapefile because their values are only maintained by ArcInfo software with data that is in ArcInfo Coverage format.

    Person responsible for change:
    Howie Sternberg
    State of Connecticut, Department of Environmental Protection
    79 Elm Street
    Hartford, Connecticut 06106
    USA

    860-424-3540 (voice)

    Data sources used in this process:
    • Source 2 - Connecticut

    Data sources produced in this process:
    • Source 3 - Connecticut_Line.shp

    Date: 2006 (change 3 of 3)
    Convert to GeoDatabase Feature Class format - Defined new Feature Class named Connecticut_State_Line; and imported the attribute definitions, loaded features and imported metadata from Connecticut_Line.shp shapefile. 
    
    Spatial Reference Properties for Feature Class:
    
    Coordinate System: NAD_1983_StatePlane_Connecticut_FIPS_0600_Feet
    XY Domain MinX: 100000; MaxX: 2247483.645
    XY Domain MinY: 200000; MaxY: 2347483.645
    Precision: 1000

    Person responsible for change:
    Howie Sternberg
    State of Connecticut, Department of Environmental Protection
    79 Elm Street
    Hartford, Connecticut 06106
    USA

    860-424-3540 (voice)

    Data sources used in this process:
    • Source 3 - Connecticut_Line.shp

    Data sources produced in this process:
    • Source 4 - Connecticut_State_Line

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How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    This data retains the political boundary (linear) feature types identified by the USGS and adds new polygon feature types of importance to the State of Connecticut for the purpose of mapping areas of the State of Connecticut on land and in the waters of Long Island Sound. All attributes have valid values. Values are within defined domains. AV_LEGEND is a broad classification of the TBPOLY_COD attribute for the polygon features of the orginal data source, Town Master from USGS. The ACREAGE (area in acres) and AREA_SQMI (area in square miles) fields were automatically calculated for each polygon feature based on computer generated feature area in square feet. The LENGTH_MI (length in miles) field was automatically calculated for each line feature base on computer generated feature length.

  2. How accurate are the geographic locations?

    This data complies with United States National Map Accuracy Standards for 1:24,000 scale maps. According to this standard, not more than 10 percent of the points tested are to be in error by more than 1/50 inch (40 feet) measured on the publication scale of a USGS 7.5 minute topographic quadrangle map.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    The completeness of the data reflects the USGS National Mapping Division standards for feature content of the data sources, which are the Large Scale (7.5 minute) Digital Line Graph (DLG) files available from the USGS. For Connecticut, the Large Scale DLG files used to create this layer are for the 1:24,000-scale topographic quadrangle maps published between 1969 and 1984.  The data is complete in the sense that it accurately reflects the contents of the most recently published USGS topographic quadrangle maps available at the time the State of Connecticut, Department of Environmental Protection began creating the layer. More recent quadrangle maps have been published by the USGS since 1984; however, the State of Connecticut did not incorporate this information into the layer. This data is not updated.

  5. How consistent are the relationships among the observations, including topology?

    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. Polygons are bound by lines. Line features conform to the following topological rules. Lines are single part. There are no duplicate lines. Lines do not self overlap. Lines do not overlap other lines. Lines intersect only at nodes, and nodes anchor the ends of all lines. Lines do not overshoot or undershoot other lines they are supposed to meet and intersect. The tests of logical consistency were performed by the State of Connecticut using ESRI ArcInfo software to maintain feature topology in ArcInfo coverage format. The data is topologically clean. The ArcInfo Clean function was repeatedly used following edits to verify topology and enforce a minimum distance between vertices of 4 feet (fuzzy tolerance) and a minimum allowed overshoot length of 10 feet (dangle length).

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How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access constraints: None. The data is in the public domain and may be redistributed.
Use constraints:
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 1:24,000 scale (1 inch = 2,000 feet). 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 and the U.S. Geological Survey, National Mapping Program as the source for this information. For example, include the following data source description when printing this layer on a map: Political Boundaries - From the Connecticut layer, compiled and published by CT DEP and USGS. Source map scale is 1:24,000.

Distributor 1 of 1

  1. Who distributes the data set?

    State of Connecticut, Department of Enviromental Protection
    79 Elm Street
    Hartford, Connecticut 06106-5127
    USA

    860-424-3540 (voice)
    860-424-4058 (FAX)
    dep.gisdata@ct.gov
    Hours of Service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

  2. What's the catalog number I need to order this data set?

    Connecticut State Line

  3. What legal disclaimers am I supposed to read?

    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.

  4. How can I download or order the data?

    • Availability in digital form:


    • Data format:
      in format Shapefile, Feature Class, ArcInfo Coverage (version ArcGIS)
      Network links:http://www.ct.gov/deep

    • Cost to order the data: An online copy of the data may be accessed without charge.


  5. Is there some other way to get the data?

    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.

  6. What hardware or software do I need in order to use the data set?

    Geographic information sytem (GIS), computer-aided drawing or other mapping software is necessary to display, view and access the information.

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Who wrote the metadata?

Dates:
Last modified: 20111207

Metadata author:
Howie Sternberg
State of Connecticut, Department of Environmental Protection
79 Elm Street
Hartford, Connecticut 06106-5127
USA

860-424-3540 (voice)
860-424-4058 (FAX)
dep.gisdata@ct.gov
Hours of Service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata(FGDC-STD-001-1998)

Metadata extensions used:
  • http://www.esri.com/metadata/esriprof80.html

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