Connecticut 20 FT Contours

+ Resource Description

Citation

Information used to reference the data.

Title: Connecticut 20 FT Contours

Originators: State of Connecticut, Department of Environmental Protection (editor and publisher)

University of Connecticut, College of Agriculture and Natural Resources (compiler, editor and publisher)

State of Connecticut, Department of Public Safety

State of Connecticut, Department of Transportation

Connecticut Joint Highway Research Council

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 20090501

Data type: vector digital data

Data location: http://www.ct.gov/dep

Description

A characterization of the data, including its intended use and limitations.

Abstract: Connecticut 20 FT Contours is line feature-based data representing ground elevation at 20 ft intervals for Connecticut. This information was obtained from the University of Connecticut, College of Agriculture and Natural Resources and is a Beta product intended for research and demonstration purposes. The data is not consistently accurate statewide. In some areas there are anomalies with the contour line information due to data gaps in the underlying LiDAR data used to generate the contour lines. This is a known limitation of the LiDAR data collected for Connecticut in 2000. Areas where the contours are incorrect are typically easy to recognize because, in relation to nearby contours, they appear too straight and angular, do not naturally curve as expected, or don't exist where they probably should. Also, contour lines may not conform very well to the shoreline of waterbodies and in many instances erroneously extend into areas of water.

Due to the anomalies in the data, use caution when viewing and analyzing this information.

Attribute information consists of fields used to classify and label features based on 20 and 100 ft contour intervals.

Purpose: Connecticut 20 FT Contours are used to depict ground elevation at 20 ft intervals or greater. Each contour line represents a line of equal elevation and indicates surface relief when used with other information such as aerial photography, soils, geology, or hydrography.

Supplemental information: Go to http://clear.uconn.edu for additional information on the LiDAR-derived data products generated from Connecticut's 2000 statewide LiDAR coverage.

Dataset credit: Aero-Metric, Inc. of Sheboygan Wisconsin was contracted by the State of Connecticut to provide the 2004 Statewide Aerial Survey of Connecticut. Contract deliverables include digital orthohotos, two sets of non-rectified prints for stereoscopic viewing, photo indexes, and LiDAR data. All 2004 Statewide Aerial Survey imagery and data products are defined under State of Connecticut contract award number RFP-990-A-14-0518-C (dated Feb 22, 2000), including contract award supplement #1 (dated Feb 28, 2002), contract award supplement #2 (dated Nov 4, 2004), contract award supplement #3 (dated Nov 26, 2004) and contract award supplement #4 (dated May 13, 2005). TerraPoint LLC of Woodlands Texas was subcontracted to create a Connecticut Statewide LIDAR dataset. Through funding by the Connecticut Joint Highway Research Council, project JH07-02, statewide LiDAR-derived datasets were subsequently created and made accessible by Associate Professor Thomas Meyer of the University of Connecticut, College of Agriculture and Natural Resources, Department of Natural Resources and the Environment. These derived data products include tiled point clouds, TINS, DEMs, and contour shapefiles available by USGS topographic quarter-quarter quadrangle area. CT DEP subsequently appended the statewide contour shapefiles into statewide datasets of 2, 10, 20, 50, and 100 foot intervals.

Language of dataset: en

Point Of Contact

Contact information for the individual or organization that is knowledgeable about the data.

Person: Howie Sternberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@po.state.ct.us

Hours of service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: CT

Postal code: 06106-5127

Country: USA

Data Type

How the data are represented, formatted and maintained by the data producing organization.

File or table name: LIDAR_2000_CONTOUR_20FT

Data type: vector digital data

Data format: File Geodatabase Feature Class

Native dataset environment: These data are maintained by the State of Connecticut using ArcGIS software developed by Environmental Systems Research Institute (ESRI) in a Microsoft Windows operating system environment.

Time Period of Data

Time period(s) for which the data corresponds to the currentness reference.

Date: 2000

Currentness reference: collection date

Status

The state of and maintenance information for the data.

Data status: Complete

Update frequency: None planned

Key Words

Words or phrases that summarize certain aspects of the data.

Theme:

Keywords: elevation, environment

Keyword thesaurus: ISO 19115 Topic Category

Theme:

Keywords: contours, LiDAR

Keyword thesaurus: none

Place:

Keywords: Connecticut, CT

Keyword thesaurus: U.S. Department of Commerce, 1987, Codes for the Identification of the States, the District of Columbia and the Outlying Areas of The United States, and Associated Areas (Federal Information Processing Standard 5-2): Washington, DC, National Institute of Standards and Technology.

Data Access Constraints

Restrictions and legal prerequisites for accessing or using the data after access is granted.

Access constraints: None. No restrictions or legal prerequisites for accessing the data. The data is in the public domain and may be redistributed.

Use constraints: None. No restrictions or legal prerequisites for using the data after access is granted. The data is suitable for use at appropriate scale, however these data are not consistently accurate statewide. In some areas there are anomalies with the contour line information due to data gaps in the underlying LiDAR data used to generate the contour lines. This is a known limitation of the LiDAR data collected for Connecticut in 2000. Areas where the contours are incorrect are typically easy to recognize because, in relation to nearby contours, they appear too straight and angular, do not naturally curve as expected, or don't exist where they probably should. Also, contour lines may not conform very well to the shoreline of waterbodies and in many instances erroneously extend into areas of water. Due to the anomalies in the data, use caution when viewing and analyzing this information. 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 as the source for this information.

Data Security Information

Handling restrictions imposed on the data because of national security, privacy or other concerns.

Security classifiction system: None

Security classification: None

Security handling: No restrictions for handling the data

+ Graphic Example

Browse Graphic

Graphic illustration of the data.

Browse graphic 1

Open - Detail view of 20 FT contours with wider 100 FT contour interval shown at approximately 1:24,000 scale.

Browse graphic 2

Open - Full view of 100 FT contours. This image is included to show coverage area of 20 ft contours, which is the same area for 100 ft contours.

Browse graphic 3

Open - Detail view of an area where the contours are incorrect due to sporadic gaps in the underlying LiDAR data used to generate the contour line features. This is a known limitation of the 2000 LiDAR data. Contours are incorrect in areas where, in relation to nearby contours, they appear too straight and angular, do not naturally curve as expected, or don't exist where they probably should. In these areas, software lacked sufficient ground elevation data to properly generate the contours.

+ Spatial Reference Information

Horizontal Coordinate System

Reference system from which linear or angular quantities are measured and assigned to the position that a point occupies.

Projected coordinate system:

Name: NAD 1983 StatePlane Connecticut FIPS 0600 Feet

Map units: survey feet

Geographic coordinate system:

Name: GCS North American 1983

Coordinate System Details

Map projection

Map projection name: 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 Coordinate Information

Planar coordinate encoding method: coordinate pair

Coordinate representation:

Abscissa resolution: 0.000328

Ordinate resolution: 0.000328

Planar distance units: survey feet

Geodetic model

Horizontal datum name: North American Datum of 1983

Ellipsoid name: Geodetic Reference System 80

Semi-major axis: 6378137.000000

Denominator of flattening ratio: 298.257222

Vertical Coordinate System

Reference system from which vertical distances (altitudes or depths) are measured.

Altitude system definition:

Altitude datum name: North American Vertical Datum of 1988

Altitude resolution: 20

Altitude distance units: feet

Altitude encoding method: Attribute values

Spatial Domain

The geographic areal domain of the data that describes the western, eastern, northern, and southern geographic limits of data coverage.

Bounding Coordinates

In Projected or local coordinates

NAD 1983 StatePlane Connecticut FIPS 0600 Feet

Boundary	Coordinate
Left	730512.261130 (survey feet)
Right	1263068.274756 (survey feet)
Top	944278.764636 (survey feet)
Bottom	555308.641659 (survey feet)

In Unprojected coordinates (geographic)

GCS North American 1983

Boundary	Coordinate
West	-73.742172 (longitude)
East	-71.781461 (longitude)
North	42.052611 (latitude)
South	40.980953 (latitude)

+ Data Structure and Attribute Information

Overview

Summary of the information content of the data, including other references to complete descriptions of entity types, attributes, and attribute values for the data.

Entity and attribute overview: Includes 20 foot ground elevation contour line features. Information encoded about these features includes an ELEVATION_FT attribute and attributes for selection and cartographic symbology classification. Use the INTERVAL_FT attribute to select and symbolize features on a map. Use the ELEVATION_FT (for 2 foot contours), LABEL_10FT, LABEL_20FT, LABEL_50FT and LABEL_100FT attribute fields to label elevation values on a map. To define a layer that only includes 10 foot contour interval features, query LiDAR 2000 Contour features for INTERVAL_FT value equal to 10 or INTERVAL_FT value equal to 20 or INTERVAL_FT value equal to 50 or INTERVAL_FT value equal to 100. This selects the elevations that are divisible by 10. Similarly use INTERVAL_FT value equal to 20 or INTERVAL_FT value equal to 100 to select 20 foot contours, INTERVAL_FT value equal to 50 or INTERVAL_FT value equal to 100 to select 50 foot intervals, INTERVAL_FT value equal to 100 to select 100 foot intervals. The selected intervals can be used to cartographically represent the contour lines or add an elevation label to certain contour lines.

Direct spatial reference method: Vector

Attributes of Connecticut 20 FT Contours

Detailed descriptions of entity type, attributes, and attribute values for the data.

Name: LIDAR_2000_CONTOUR_20FT

Type of object: Feature Class

Geometry type: Polyline

Number of records: 318461

Description: 20 FT ground elevation contours represented as line features

Source: State of Connecticut, Department of Environmental Protection

Attributes

OBJECTID

Definition: Internal feature number.

Alias: OBJECTID Type: OID Width: 4 Precision: 0 Scale: 0

Attribute values: Sequential unique whole numbers that are automatically generated.

Attribute definition source: ESRI

SHAPE

Definition: Feature geometry.

Alias: SHAPE Type: Geometry Width: 0 Precision: 0 Scale: 0

Attribute values: Coordinates defining the features.

Attribute definition source: ESRI

ELEVATION_FT

Definition: Elevation of contour feature in feet

Alias: ELEVATION_FT Type: Integer Width: 4 Precision: 0 Scale: 0

Attribute definition source: Terrapoint LLC

INTERVAL_FT

Definition: The type of contour line interval (e.g. 2, 10, 20, 50, and 100) based on the value of ELEVATION_FT. The larger interval - 100 instead of 50 for a 200 ft contour line - is assigned to a contour line. For example, a contour line interval value of 100 is assigned to features with ELEVATION_FT values of 100, 200, 300, 400, 500, etc. A contour line interval value of 50 is assigned to features with ELEVATION_FT values of 50, 150, 250, 350, 450, etc. A contour line interval value of 20 is assigned to features with ELEVATION_FT values of 20, 40, 60, 80, 120, etc. A contour line interval value of 10 is assigned to features having ELEVATION_FT values of 10, 30, 70, 90, 110, etc. A contour line interval value of 2 is assigned to features with ELEVATION_FT values of 2, 4, 6, 8, 12, 14, 18, etc. These values are used for querying subsets and classifying features for symbology purposes. For example, to make a 10 ft contour interval view of the data, query INTERVAL_FT IN (10, 20, 50, 100). To make a 20 ft contour interval view of the data, query INTERVAL_FT IN (20, 100). To make a 50 ft contour interval view of the data, query INTERVAL_FT IN (50, 100). To make a 100 ft contour interval view, query INTERVAL_FT IN (100).

Alias: INTERVAL_FT Type: Integer Width: 4 Precision: 0 Scale: 0

Attribute domain values

Value	Definition
20	20 foot contour interval
100	100 foot contour interval

Attribute definition source: State of Connecticut, Department of Environmental Protection

LABEL_20FT

Definition: 20 FT Contour Label Field - An elevation value evenly divisable by 20.

Alias: LABEL_20FT Type: SmallInteger Width: 2 Precision: 0 Scale: 0

Attribute domain values

Value	Definition
20	20 ft label
40	40 ft label
60	60 ft label
80	80 ft label
100	100 ft label
etc.	and so on

Attribute definition source: State of Connecticut, Department of Environmental Protection

LABEL_100FT

Definition: 100 FT Contour Label Field - An elevation value evenly divisable by 100.

Alias: LABEL_100FT Type: SmallInteger Width: 2 Precision: 0 Scale: 0

Attribute domain values

Value	Definition
100	100 ft label
200	200 ft label
300	300 ft label
400	400 ft label
500	500 ft label
etc.	and so on

Attribute definition source: State of Connecticut, Department of Environmental Protection

QUAD_NO

Definition: Number assigned to USGS quadrangles that cover Connecticut. This information can help identify the original quarter-quarter quadrangle tile shapefile data source for an particular contour line.

Alias: QUAD_NO Type: SmallInteger Width: 2 Precision: 0 Scale: 0

Attribute definition source: State of Connecticut, Department of Environmental Protection

SHAPE_Length

Definition: Length of feature in internal units.

Alias: SHAPE_Length Type: Double Width: 8 Precision: 0 Scale: 0

Attribute values: Positive real numbers that are automatically generated.

Attribute definition source: ESRI

ESRI Feature Description

Description of spatial objects in the data using the Environmental Systems Research Institute (ESRI) terminology.

Environmental Systems Research Institute (ESRI) terms

LIDAR_2000_CONTOUR_20FT

ESRI feature type: Simple

Geometry type: Polyline

Topology: FALSE

Feature count: 318461

Spatial index: TRUE

Linear referencing: FALSE

SDTS Feature Description

Description of point and vector spatial objects in the data using the Spatial Data Transfer Standards (SDTS) terminology.

Spatial data transfer standard (SDTS) terms

LIDAR_2000_CONTOUR_20FT

Type: String

Count: 318461

+ Data Quality and Accuracy Information

General

Information about the fidelity of relationships, data quality and accuracy tests, omissions, selection criteria, generalization, and definitions used to derive the data.

Logical consistency report: 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 not performed by CT DEP. No automated procedures or tests were performed by CT DEP to guarantee desired topology other than limited visual inspection.

Completeness report: The completeness of the data reflects the feature content of the data sources, which include the LiDAR 2000 contour shapefiles and the LiDAR 2000 elevation points. The LiDAR 2000 Contours layer contains automatically generated contour lines that may contain errors or inconsistancies inherent in the automated process. The LiDAR 2000 Contours layer contains errors or inconsistancies related to errors inherent in the original LiDAR elevation data capture. There are no plans to update or correct these data.

Attribute Accuracy

Accuracy of the identification of data entities, features and assignment of attribute values.

Attribute accuracy report: The LiDAR 2000 Contours layer retains the feature types and information identified by the State of Connecticut, Department of Environmental Protection and obtained from the LiDAR 2000 contour shapefiles. All attributes have valid values. Values are within defined domains. ELEVATION_FT attribute values are inherited from the LiDAR 2000 contour shapefiles. Attribute INTERVAL_FT was populated through successive selections of ELEVATION_FT values based on calculations to select values for 10 foot, 20 foot, 50 foot and 100 foot intervals. Attributes for LABEL_10FT, LABEL_20FT, LABEL_50FT, LABEL_100FT were populated through calculations. Attribute QUAD_NO was populated by assigning the number of the USGS quadrangle that the contours are located within.

Positional Accuracy

Accuracy of the positional aspects of the data.

Horizontal accuracy report: The horizontal positional accuracy of this data is not known. This data underwent automated processes to interpolate and create 2 foot elevation contours from the 20-foot posting LiDAR 2000 point data. The horizontal positional accuracy of the 20-foot posting LiDAR 2000 point data is approximately 3 feet on the ground. The data is not consistently accurate statewide. In some areas there are anomalies with the contour line information areas due to data gaps in the underlying LiDAR data used to generate the contour lines. This is a known limitation of the LiDAR data collected for Connecticut in 2000. Areas where the contours are incorrect are typically easy to recognize because, in relation to nearby contours, they appear too straight and angular, do not naturally curve as expected, or don't exist where they probably should. Also, contour lines may not conform very well to the shoreline of waterbodies and in many instances erroneously extend into areas of water. Due to the anomalies in the data, use caution when viewing and analyzing this information.

Vertical accuracy report: The data is not consistently accurate statewide. In some areas there are anomalies with the contour line information areas due to data gaps in the underlying LiDAR data used to generate the contour lines. This is a known limitation of the LiDAR data collected for Connecticut in 2000. Areas where the contours are incorrect are typically easy to recognize because, in relation to nearby contours, they appear too straight and angular, do not naturally curve as expected, or don't exist where they probably should. Also, contour lines may not conform very well to the shoreline of waterbodies and in many instances erroneously extend into areas of water. Due to the anomalies in the data, use caution when viewing and analyzing this information.

+ Data Source and Process Information

Data Sources

Information about the source data used to construct or derive the data.

Data source information

Contour Shapefiles

Title: Quad-Sixteenth LiDAR Contour Shapefiles

Originators: University of Connecticut, College of Agriculture and Natural Resources (data compiler and editor)

Series name: Contour Shapefiles

Publisher: University of Connecticut, Center for Land Use Education and Research (CLEAR)

Publication place: Storrs, Connecticut, USA

Publication date: Unknown Publication time: Unknown

Data type: map

Data location: http://clear.uconn.edu

Media: disc

Source contribution: These statewide line features of elevation contours were generated by UConn using point elevation data from the Connecticut Statewide LiDAR dataset. The Connecticut Statewide LiDAR dataset consists of x, y, and z point-data from an interpolated surface model ("bare-earth") derived from an Airborne LIDAR Topographic Mapping System (ALTMS). The x, y, and z values are stored in space-delimited ASCII files. These LiDAR elevation data are at a nominal 20-foot posting. The contours were prepared in one-sixteenth USGS quadrangle units. To understand the quad-sixteenth visualize a USGS quadrangle bisected vertically and horizontally into four sections. Each of these sections is in turn bisected vertically and horizontally into four sections, thus forming sixteen equal rectangles.

Currentness reference: 2000

Appended Contours

Title: Quadrangle LiDAR Contour Shapefiles

Originators: State of Connecticut, Department of Environmental Protection (data editor)

Publication date: Unpublished Material

Media: disc

Source contribution: This data source refers to all features of quad-sixteenth contour shapefiles for each USGS quadrangle combined into one shapefile per quadrangle.

Currentness reference: 2000

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Statewide Contour File Geodatabase

Title: Connecticut 2 FT Contours

Originators: State of Connecticut, Department of Environmental Protection (data editor and publisher)

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 2009

Media: disc

Source contribution: This is a statewide dataset that includes features from the individual quadrangle data sources. This dataset is in both File Geodatabase and ArcSDE feature class format. In ArcSDE, spatial views were created to establish 10, 20, 50, and 100 ft contour interval subsets, which were exported as the following File Geodatabase feature classes: LIDAR_2000_CONTOUR_10FT, LIDAR_2000_CONTOUR_20FT, LIDAR_2000_CONTOUR_50FT, and LIDAR_2000_CONTOUR_100FT.

Currentness reference: 2000

Connecticut Polygon

Title: Connecticut State Polygon

Originators: State of Connecticut, Department of Environmental Protection

Series name: Connecticut Polygon

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 1994

Edition: 2005

Data location: http://www.ct.gov/dep

Other citation details: Map scale denominator: 24000

Media: disc

Source contribution: Provided the polygon used to clip the contours to the state outline.

Currentness reference: publication date

LIS Polygon

Title: Long Island Sound Modified Polygon

Series name: LIS Polygon

Media: disc

Source contribution: Provided the polygon to clip the contours along the Long Island Sound coastline.

Currentness reference: publication date

Process Steps

Information about events, parameters, tolerances and techniques applied to construct or derive the data.

Process step information

Process Step 1

Process description: Append shapefiles - Using ESRI ArcGIS software, append all quad-sixteenth contour shapefiles for each USGS quadrangle into a single shapefile for each quadrangle. A geoprocessing model able to append the shapefiles in batch was used. The lines in each quad were not dissolved. Tests showed that retaining the quad-sixteenth feature pattern helped create more uniform feature size. Tests also showed that dissolving would introduce an unacceptable number of errors into the data.

Person: Diana Danenberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 200901

Process software and version: ArcGIS 9.3

Data Source used

Contour Shapefiles

Title: Quad-Sixteenth LiDAR Contour Shapefiles

Originators: University of Connecticut, College of Agriculture and Natural Resources (data compiler and editor)

Series name: Contour Shapefiles

Publisher: University of Connecticut, Center for Land Use Education and Research (CLEAR)

Publication place: Storrs, Connecticut, USA

Publication date: Unknown Publication time: Unknown

Data type: map

Data location: http://clear.uconn.edu

Media: disc

Currentness reference: 2000

Data Source produced

Appended Contours

Title: Quadrangle LiDAR Contour Shapefiles

Originators: State of Connecticut, Department of Environmental Protection (data editor)

Publication date: Unpublished Material

Media: disc

Source contribution: This data source refers to all features of quad-sixteenth contour shapefiles for each USGS quadrangle combined into one shapefile per quadrangle.

Currentness reference: 2000

Process Step 2

Process description: Load contours into geodatabase - Using ESRI ArcGIS software, create a file geodatabase and import the features in each appended contour shapefile into feature classes. During the import the attribute field named Value is renamed ELEVATION_FT. This field stores the elevation assigned to each contour line.

Person: Diana Danenberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 200901

Process software and version: ArcGIS9.3

Data Source used

Appended Contours

Title: Quadrangle LiDAR Contour Shapefiles

Originators: State of Connecticut, Department of Environmental Protection (data editor)

Publication date: Unpublished Material

Media: disc

Source contribution: This data source refers to all features of quad-sixteenth contour shapefiles for each USGS quadrangle combined into one shapefile per quadrangle.

Currentness reference: 2000

Data Source produced

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Process Step 3

Process description: Clean up feature records - Using ESRI ArcGIS software, select all records in each contour feature class with a SHAPE_Length attribute of < .001 and delete. This removes features that are zero length lines and essentially are points. Using ESRI ArcGIS software, select all records in each contour feature class with an ELEVATION_FT of 0 or NULL and delete. This removes features that do not have a valid elevation assigned to them. The zero elevations contours occur over water bodies in about 30 quads with the highest concentrations occurring over Long Island Sound. These contour lines occur erratically and do not represent a base elevation.

Person: Diana Danenberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 200901

Process software and version: ArcGIS9.3

Data Source used

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Data Source produced

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Process Step 4

Process description: Clean up features - Using ESRI ArcGIS software, select and delete small line features with the characteristics of length less than 100 feet and the beginning and ending point of the line are the same (small closed rings). Using a geoprocessing model designed to use in batch, temporary attribute fields were added and calculated for the X coordinate start, X coordinate end, Y coordinate start, Y coordinate end. Select records where "XCoorStart = XCoorEnd and YCoorStart = YCoorEnd and shape_length <= 100" and delete. The rings fitting these criteria are roughly 32 feet in diameter and appear to be anomalies or too small to be significant. This eliminates a large number of features in each feature class that provide little or no benefit. Refer to the quad-based appended shapefiles to see complete feature set.

Person: Diana Danenberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 200901

Process software and version: ArcGIS9.3

Data Source used

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Data Source produced

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Process Step 5

Process description: Clip contour feature classes - Using ESRI ArcGIS software, clip and remove contour lines that extend outside the boundary of the State of Connecticut. The State of Connecticut polygon on file at DEP was used to clip off the landward contours that extend outside the state boundary. No offset was used. Using ESRI ArcGIS software, clip and remove contour lines that extend into Long Island Sound and its bays and harbors. The Long Island Sound polygon from hydrography data on file at DEP was modified and used to clip off seaward extending contours. These contour lines often contain processing artifacts from the original contour generation and are not intended to capture the water's surface. The Long Island Sound polygon was prepared before use. It was buffered to reduce its size by 40 feet from the mainland shoreline and offshore islands. A visual inspection of the Long Island Sound polygon, the contour lines and the 2004 orthophotographs was done along all shorelines. The Long Island Sound polygon outline was manually reshaped to accommodate variations in the contours and the shoreline on the orthophotograph such that all contours extend at least 40 feet.

Person: Diana Danenberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 200901

Process software and version: ArcGIS9.3

Data Source used

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Connecticut Polygon

Title: Connecticut State Polygon

Originators: State of Connecticut, Department of Environmental Protection

Series name: Connecticut Polygon

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 1994

Edition: 2005

Data location: http://www.ct.gov/dep

Other citation details: Map scale denominator: 24000

Media: disc

Source contribution: Provided the polygon used to clip the contours to the state outline.

Currentness reference: publication date

LIS Polygon

Title: Long Island Sound Modified Polygon

Series name: LIS Polygon

Media: disc

Source contribution: Provided the polygon to clip the contours along the Long Island Sound coastline.

Currentness reference: publication date

Data Source produced

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Process Step 6

Process description: Attribute enhancements - Using ESRI ArcGIS software and geoprocessing models designed to use batch processing, edit attribute fields. Remove the temporay fields used in Process Step 4. The field named ID did not contain data and was deleted. A field named QUAD_NO was added to store the number of each parent quadrangle to make it possible to backtrack to contour quad sources after the data is stored as a single datalayer. A field named INTERVAL_FT was added to classify the contour lines with elevation value ranges useful for symbolizing or selection of features. This field was populated by first assigning every contour line the base interval of 2 ft. In succession, the elevation values that participate in 10 ft, 20 ft, 50 ft and 100 ft intervals were selected and assigned. To use an interval remember to select all the intervals divisible by (contain) the number you are interested in. For example, to select elevations every 20 feet you should select INTERVAL_FT = 20 and INTERVAL_FT = 100.

Person: Diana Danenberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 200902

Process software and version: ArcGIS9.3

Data Source used

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Data Source produced

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Process Step 7

Process description: Using ESRI ArcCatalog software, created a File GeoDatabase line feature class to store all of the 2 ft contour data. The individual quadrangle-based contour line feature classes are appended into a single feature class that included all 2ft contours statewide.

Person: Howie Sternberg

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106

Country: USA

Process date: 200904

Process software and version: ArcGIS 9.3

Data Source used

Contour Geodatabase

Title: Quadrangle LiDAR Contour Geodatabase

Series name: Countour Geodatabase

Media: disc

Source contribution: This data source is all the quadrangle contour shapefiles entered into an ESRI file geodatabase.

Currentness reference: 2000

Data Source produced

Statewide Contour File Geodatabase

Title: Connecticut 2 FT Contours

Originators: State of Connecticut, Department of Environmental Protection (data editor and publisher)

Publisher: State of Connecticut, Department of Environmental Protection

Publication place: Hartford, Connecticut, USA

Publication date: 2009

Media: disc

Currentness reference: 2000

+ Data Distribution Information

General

Description of the data known by the party from whom the data may be obtained, liability of party distributing data, and technical capabilities required to use the data.

Resource description: Connecticut 20 FT Contours

Distribution liability: 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.

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

Distribution Point of Contact

Contact information for the individual or organization distributing the data.

Organization: State of Connecticut, Department of Environmental Protection

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@po.state.ct.us

Hours of service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106-5127

Country: USA

Standard Order Process

Common ways in which data may be obtained.

Digital form:

Format name: File Geodatabase

Format version number: ArcGIS 9

Size of the data: 0.057

Transfer size: 0.057

File decompression technique: no compression applied

Digital transfer option:

Online option:

Computer information:

Network address:

Network resource name: http://www.ct.gov/dep

Fees: A copy of the data may be accessed without charge

Custom Order Process

Description of custom distribution services available.

Custom order process: 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.

+ Metadata Reference

Metadata Date

Dates associated with creating, updating and reviewing the metadata.

Last updated: 20100713

Language of metadata: en

Metadata Point of Contact

Contact information for the individual or organization responsible for the metadata information.

Organization: State of Connecticut, Department of Environmental Protection

Person: Howie Sternberg

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@po.state.ct.us

Hours of service: Monday to Friday, 08:30 to 16:30 Eastern Standard Time

Address type: mailing and physical address

Address: 79 Elm Street

City: Hartford

State or Province: Connecticut

Postal code: 06106-5127

Country: USA

Metadata Access Constraints

Restrictions and legal prerequisites for accessing or using the data after access is granted.

Access constraints: None. No restrictions or legal prerequisites for accessing the metadata.

Use constraints: None. No restrictions or legal prerequisites for using the metadata after access is granted.

Metadata Security Information

Handling restrictions imposed on the metadata because of national security, privacy or other concerns.

Security classifiction system: None

Security classification: None

Security handling: No restrictions for handling the metadata.

Metadata Standards

Description of the metadata standard used to document the data and reference to any additional extended profiles to the standard used by the metadata producer.

Standard name: FGDC Content Standards for Digital Geospatial Metadata

Standard version: FGDC-STD-001-1998

Time convention: local time

Metadata profiles defining additonal information:

Profile: ESRI Metadata Profile

Online linkage: http://www.esri.com/metadata/esriprof80.html

FGDC Plus Metadata Stylesheet

Stylesheet: FGDC Plus Stylesheet

File name: FGDC Plus.xsl

Version: 2.2

Description: This metadata is displayed using the FGDC Plus Stylesheet, which is an XSL template that can be used with ArcGIS software to display metadata. It displays metadata elements defined in the Content Standard for Digital Geospatial Metadata (CSDGM) - aka FGDC Standard, the ESRI Profile of CSDGM, the Biological Data Profile of CSDGM, and the Shoreline Data Profile of CSDGM. CSDGM is the US Federal Metadata standard. The Federal Geographic Data Committee originally adopted the CSDGM in 1994 and revised it in 1998. According to Executive Order 12096 all Federal agencies are ordered to use this standard to document geospatial data created as of January, 1995. The standard is often referred to as the FGDC Metadata Standard and has been implemented beyond the federal level with State and local governments adopting the metadata standard as well. The Biological Data Profile broadens the application of the CSDGM so that it is more easily applied to biological data that are not explicitly geographic (laboratory results, field notes, specimen collections, research reports) but can be associated with a geographic location. Includes taxonomical vocabulary. The Shoreline Data Profile addresses variability in the definition and mapping of shorelines by providing a standardized set of terms and data elements required to support metadata for shoreline and coastal data sets. The FGDC Plus Stylesheet includes the Dublin Core Metadata Element Set. It supports W3C DOM compatible browsers such as IE7, IE6, Netscape 7, and Mozilla Firefox. It is in the public domain and may be freely used, modified, and redistributed. It is provided "AS-IS" without warranty or technical support.

Instructions: On the top of the page, click on the title of the dataset to toggle opening and closing of all metadata content sections or click section links listed horizontally below the title to open individual sections. Click on a section name (e.g. Description) to open and close section content. Within a section, click on a item name (Status, Key Words, etc.) to open and close individual content items. By default, the Citation information within the Description section is always open for display.

Download: FGDC Plus Stylesheet is available from the ArcScripts downloads at www.esri.com.