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Connecticut Trail Feature Point

Frequently-asked questions:


What does this data set describe?

Title:
Connecticut Trail Feature Point

Abstract:
Trail Feature Points are point features in the Statewide Trails Database that describe where trail infrastructure exists such as bridges, culverts, utility lines, survey markers and gates. Maintenance issues can also be stored in this table such as junk cars or trail washouts.

Supplemental information:
Statewide Trails Database model version number 1.0. Refer to the Getting_Started.htm document for how to prepare and load existing trail data into the Statewide Trails Database format. A Statewide Trails extension (statewidetrails.avx) is also available for ArcView 3x software for creating identical field attributes in Shapefile format. The extension is useful in preparing data initially collected and maintained in Shapefile format for loading into GeoDatabase Feature Class format.

  1. How should this data set be cited?

    State of Connecticut, Department of Environmental Protection (data compiler, editor and publisher), 20060601, Connecticut Trail Feature Point: State of Connecticut, Department of Environmental Protection, Hartford, Connecticut, USA.

    Online links:
    Other citation details:
    Refer to the Trail System data table in the Statewide Trails Database for complete listing of all agencies and organizations collecting and providing information for the Statewide Trails Database. Data compiled at various scales.

  2. What geographic area does the data set cover?

    Bounding coordinates:
    West: -73.264509
    East: -71.783958
    North: 42.017208
    South: 41.263474

  3. What does it look like?

    http://www.cteco.uconn.edu/metadata/dep/browsegraphic/trailsdetailview.gif (GIF)
    Detail view of a Trail System with Trail, Trail Access, Point of Interest and Roadway features.

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

    Calendar date: 20060601
    Currentness reference:
    publication date

  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 Park, State Forest, municipal park, land trust, or trail system name

      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (1757)

    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?

    depgis.DEP.TRAIL_FEATURE
    Point features that describe where trails can be accessed at trail heads, state and municipal parks and forests, or other points of departure. (Source: State of Connecticut, Department of Environmental Protection and other trail data collecting agencies and organizations in Connecticut.)

    OBJECTID
    Internal feature number. (Source: ESRI)
                      

    Sequential unique whole numbers that are automatically generated.

    SHAPE
    Feature geometry. (Source: ESRI)
                      

    Coordinates defining the features.

    TrailSysId
    Trail System Id - An Id that associates and relates Trail Access Point features to a Trail System. This is a required field that matches a value in the Trail_System table. All Trail Access Point features that are part of a Trail System are assigned the same Trail System Id. Note, an agency or organization wishing to provide data for inclusion in the Connecticut Statewide Trails database must use Trail System Ids assigned by the State of Connecticut, Department of Environmental Protection that do not conflict with Ids used by other trail data providers. Please contact Howie Sternberg at the Connecticut Department of Environmental Protection at 860-424-3594 to obtain a block of Trail Systems Ids for your use. Trail System Ids are allocated to data providers in blocks of 50. (Source: State of Connecticut, Department of Environmental Protection)
                      

    ValueDefinition
    1 - 100
    Block of 100 Trail System Ids reserved for trail systems submitted by CT DEP
    101 - 150
    First block of 50 Trail System Ids.
    151 - 200
    Second block of 50 Trail System Ids.
    201 - 250
    Third block of 50 Trail System Ids.
    251 - 300
    Fourth block of 50 Trail System Ids.
    etc.
    Continued allocation of Trail System Ids in blocks of 50, as required.

    FeatureCode
    Integer corresponding to feature type such as Amenity, Bridge, Building, Gate, etc. (Source: State of Connecticut, Department of Environmental Protection)
                      

    Comment
    Comment (Source: State of Connecticut, Department of Environmental Protection)
                      

    FeatureName
    Building name, Stream name, Road name or other appropriate name. (Source: State of Connecticut, Department of Environmental Protection)
                      

    FeatureType
    FeatureType domain varies by Trail Feature type such as Hydrant, Power Pole, Overhead Utility, etc for Utility Types. (Source: State of Connecticut, Department of Environmental Protection)
                      

    FeatureCondition
    Condition values vary by Trail Feature type such as Good or Damged for Gates. (Source: State of Connecticut, Department of Environmental Protection)
                      

    Entity and attribute overview:
    Table Relationships:
    
    1. Trail_Access point features are joined to the Town_Data table via the TownNo field.
    2. Trail_Access point features are joined to the Trail_System table via the TrailSysId field.
    
    Attributes:
    
    1. Trail System Id - Uniquely identifies a logical system of trails and is a common identifier found in all tables. All Trail line, Trail Access point, Trail Interest point, and Roadway line features for a given Trail System are assigned the same Trail System Id. An agency or organization wishing to provide trail data for inclusion in the Connecticut Statewide Trails Database must use Trail System Ids assigned by the State of Connecticut, Department of Energy and Environmental Protection so that they do conflict with Trail System Ids used by other trail data providers. Please contact the Connecticut Department of Energy and Environmental Protection at 860-424-3540 to obtain a block of Trail Systems Ids for your use. Trail System Ids are allocated to data providers in blocks of 50. 
    
    2. Field Types - Most fields are text fields except for Trail System Id (TrailSysId), Town Number (TownNo) field in the Trail Access Point feature class and the number of Parking spaces available (ParkingNum).
    
    3. Text Fields - Most fields without domains are free-form text fields. Depending on the field, certain rules and conventions need to be applied when entering data in these fields. For example, the Trail Marker (TrailMark) field in the Trail line feature class is to be left blank if a trail is not marked. Do not populate the field with the words "unmarked" or "unblazed", for example. Leave all free-form text fields blank if information is not applicable.
    
    4. Field Domain Range - Attribute domains represent a fixed list of values to choose from for a particular field. Domain values are case sensitive text field values that must be entered exactly as specified in the metadata enumerated domains. For example the Bike attribute uses a true-false domain that stores text information as either "True" or "False", not "TRUE" or "FALSE"; "true" or "false"; "yes" or "no", or 0 or -1, etc. Any value other than "True" or "False" is invalid, with the exception of the NULL option, which is a field value that is only available to data in GeoDatabase and not Shapefile format. Adhering to domain values is important to keep in mind when using the field Calculate option in ArcView 3x or ArcGIS 9x to assign domain attribute values to selected features at once. It is easy to inadvertently calculate values outside the range of a field's domain.
    
    5. Default Values - The default domain values for each field is indicated in the metadata for the field such as "True" for the Hiking or "Unpaved" for the Trail Surface (TrailSurf) field in the Trail line feature class. These are the default values when adding new table records or digitizing new features.
    
    6. Null Field Values - For fields with enumerated domains in GeoDatabase format, NULL is a valid domain value that can be used to signify information is unknown. NULL implies that the information is Unknown. It does not imply that the information is not applicable. 
    
    7. Null Field Values (Shapefile format) - For fields with enumerated domains in Shapefile format, NULL is not a valid value so do not enter NULL or "NULL" even though NULL is allowed in GeoDatabase format. For data in Shapefile, leave the field blank if the value is unknown.
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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?

To facilitate the management and sharing of information for trail mapping, management, planning, and information dissemination purposes.

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How was the data set created?

  1. Where did the data come from?

  2. What changes have been made?

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

  1. How well have the observations been checked?

    All attributes have valid values. Values are within defined domains. Accuracy tests performed by data collector and data provider.

  2. How accurate are the geographic locations?

    Horizontal accuracy varies depending on the methodology used by data collectors to compile, map and digitize individual trail systems. Information was prepared by collecting trail positions in the field using GPS equipment, digitizing trail maps, compiling information onto a planimetric correct base and digitizing, or by copying previously digitized road and trail centerline features.
    
    Trail Access Point features do not have to be as accurately mapped as Trail line features because these point locations are only used to represent the general vicinity for where a trail or a system of trails can be accessed at a state park or along side a public road, for example. Trail Access point features can be screen digitized and do not have to connect to or touch the ends of Trail line features, for example. It is not necessary to GPS their locations. Photo and map interpolation are adequate means for positioning these features relative to trails.
    
    For trail access along a public road, the point can be digitized along the where parking is provided nearby. At a park, one point can be used to represent the starting point of a group of trails. A point for each trail head at a park need not be digitized. For a typical, park, one Trail Access Point feature is usually sufficient. For larger parks, a Trail Access Point can be located at the parking lot nearest to most of the trails. And for small parks, the point can be digitized in the middle of the parcel next to the location of trails. Also, it is possible to simply include a Trail Access point feature without digitizing the associated Trail (line) features in order to represent very small trail systems such as a short boardwalk or nature trail on a very small parcel.
    
    A conservative estimate of overall horizontal accuracy is based on the assumption that Trail line feature data is generally collected at scales that are at least as accurate as 1:24,000 scale (1 inch = 2,000 feet), which is the scale of the USGS 7.5 minute topographic quadrangle map. But this is only an assumption on the part of the State of Connecticut, Department of Environmental Protection (CT DEP), which coordinated the design of the Statewide Trails Database. For example, GPS data collected by CT DEP is generally expected to be at 1-4m accuracy, data interpreted and digitized from 2004 aerial photographs at +- 20ft, and data derived from 1:24,000-scale road and trail centerlines at +- 40ft.
    

  3. How accurate are the heights or depths?

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

    As complete as data is collected by data collectors and supplied by data providers to the Statewide Trails Database. Because it is designed to include more and more information over time, the Statewide Trails Database does not represent a complete inventory of all greenways, trails, and bike routes. Rather, it is intended to be a Statewide repository of currently available information.

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

    Point features conform to the following topological rules. Points are single part. There are no duplicate points. Points do not overlap. Establishment of logical consistency was performed by the respective data collector (agencies) responsible for manually creating and controlling feature topology in eather Shapefile or Geodatabase format. No automated procedures or tests were performed to guarantee desired topology other than visual inspection.

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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. Trail line feature information was prepared by collecting trail positions in the field using GPS equipment, digitizing trail maps, compiling information onto a planimetric correct base and digitizing, or by copying previously digitized road and trail centerline features. Horizontal accuracy varies depending on the methodology used to map and digitize each trail system. Consequently, as a whole, these data are generally not intended for maps printed at scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet). Refer to the Horizontal Accuracy Notes attribute in the Trail line feature and Roadway line feature class for more specific horizontal accuracy assessments when mapping individual trail systems at larger (more accurate) scales. Trail Access point and Trail Interest point feature information was prepared using similar methods, with horizontal accuracy varying accordingly. 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. The State of Connecticut, Department of Environmental Protection and all other Originators (referenced in the Citation section of this metadata), should be acknowledged as the data source in products derived from the trail data. For example, include the following data source description on a map: Trails - From the Connecticut Statewide Trails layer, compiled and published by CT DEP and other trail data collecting agencies and organizations. Source map scale varies.

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 Statewide Trails Database

  3. What legal disclaimers am I supposed to read?

  4. How can I download or order the data?

    • Availability in digital form:


    • Data format:
      in format Shapefile, Feature Class (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: 20111215

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
  • http://www.esri.com/metadata/esriprof80.html
  • http://www.esri.com/metadata/esriprof80.html

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