Connecticut Terrain Dataset, version 1

+ Resource Description

Citation

Information used to reference the data.

Title: Connecticut Terrain Dataset, version 1

Originators: State of Connecticut, Department of Energy and Environmental Protection

Edition: 1

Data type: vector digital data

Description

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

Abstract:

Connecticut Terrain Dataset, version 1 is a digital terrain model of the state of Connecticut in ESRI terrain dataset format. The primary elevation point data source for the terrain is the Connecticut 2000 LiDAR Masspoints. The USGS Topographic Map Masspoints provide additional elevation data in areas of data gaps in the Connecticut 2000 LiDAR Masspoints. The terrain also makes use of two boundary feature classes to clip the terrain to the Connecticut state boundary at different scale thresholds. This dataset is labeled "version 1" because as new LiDAR data becomes available, new statewide terrain datasets will be created.

Purpose:

Connecticut Terrain Dataset, version 1 has a wide range of uses including visual display and querying of elevation, slope, aspect, and contours; generation of raster digital elevation models (DEMs) and contour lines; and use as an input for analysis tasks such as creating viewsheds, calculating surface area and volume, and interpolating z-values to other data layers.

Dataset credit:

The primary data source for the terrain, the Connecticut 2000 LiDAR Masspoints, was a part of the 2004 Statewide Aerial Survey of Connecticut, provided by Aero-Metric, Inc. of Sheboygan, Wisconsin on a contract with the State of Connecticut. TerraPoint LLC of Woodlands, Texas, was subcontracted to create a Connecticut Statewide LiDAR dataset.

Point Of Contact

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

Organization: State of Connecticut, Department of Energy and Environmental Protection

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@ct.gov

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

Address type: Unknown

Address:

79 Elm Street

City: Hartford

State or Province: CT

Postal code: 06106

Country: US

Data Type

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

Data type: vector digital data

Native dataset environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcGIS 10.0.0.2414

Data Access Constraints

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

Access constraints:

None

Use constraints:

These data are not consistently accurate statewide. Users should review the following description of source data in order to determine appropriate uses of this information.

The primary point data source is 20-foot posting lidar data collected in 2000, which has a horizontal positional accuracy of approximately 3 feet on the ground. The lidar point data has known limitations including data gaps. The secondary point data source that contributes to the terrain dataset was compiled by Center for Land Use Education and Research (CLEAR) at the University of Connecticut, College of Agriculture and Natural Resources. It is a collection of points intended to fill in gaps in the lidar data with coarser data based on contour lines from USGS topographic maps. Before building the terrain dataset, this secondary point data source was further edited by DEP to remove unnecessary points that occurred in areas of dense lidar point data.

+ Graphic Example

Browse Graphic

Graphic illustration of the data.

Browse graphic 1

Open - Full view of Connecticut Terrain Dataset Version 1 - Elevation

Browse graphic 2

Open - Full view of Connecticut Terrain Dataset Version 1 - Contours

Browse graphic 3

Open - Full view of Connecticut Terrain Dataset Version 1 - Slope

Browse graphic 4

Open - Full view of Connecticut Terrain Dataset Version 1 - Aspect

Browse graphic 5

Open - Detail view of Connecticut Terrain Dataset Version 1 - Elevation

Browse graphic 6

Open - Detail view of Connecticut Terrain Dataset Version 1 - Contours

Browse graphic 7

Open - Detail view of Connecticut Terrain Dataset Version 1 - Slope

Browse graphic 8

Open - Detail view of Connecticut Terrain Dataset Version 1 - Aspect

Browse graphic 9

Open - Coverage of data sources in Connecticut Terrain Dataset Version 1

+ 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.

Coordinate System Details

Map projection

Map projection name: NAD 1983 StatePlane Connecticut FIPS 0600 Feet

Standard parallel: 41.2

Standard parallel: 41.86666666666667

Longitude of central meridian: -72.75

Latitude of projection origin: 40.83333333333334

False easting: 999999.999996

False northing: 499999.999998

Planar Coordinate Information

Planar coordinate encoding method: coordinate pair

Coordinate representation:

Abscissa resolution: 0.0003280833333333334

Ordinate resolution: 0.0003280833333333334

Planar distance units: Foot_US

Geodetic model

Horizontal datum name: D North American 1983

Ellipsoid name: GRS 1980

Semi-major axis: 6378137.0

Denominator of flattening ratio: 298.257222101

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 Unprojected coordinates (geographic)

Boundary	Coordinate
West	-73.742172 (longitude)
East	-71.781365 (longitude)
North	42.052612 (latitude)
South	40.988796 (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.

Direct spatial reference method: Vector

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

Feature class

Type: GT-polygon composed of chains

Count: 1

Feature class

Type: Entity point

Count: 62152

Feature class

Type: Composite object

Count: 49611

Feature class

Type: GT-polygon composed of chains

Count: 263

+ Data Source and Process Information

Data Sources

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

Data source information

Connecticut 2000 LiDAR Masspoints

Title: Connecticut 2000 LiDAR Masspoints

Media: None

Source contribution:

The Connecticut 2000 LiDAR Masspoints are the main elevation data source for the terrain dataset. The data is 20-foot posting covering the state of Connecticut, and has a horizontal positional accuracy of approximately 3 feet on the ground. However, the data has known limitations, including data gaps.

USGS Topographic Map Masspoints

Title: USGS Topographic Map Masspoints

Media: None

Source contribution:

These point data were used to fill in some of the gaps that are a known limitation of the Connecticut 2000 LiDAR Masspoints. This data were derived from contour lines appearing on USGS 1:24,000-scale Digital Raster Graphics (DRGs) by the Center for Land Use Education and Research (CLEAR). The data were further edited by CT DEP to remove points that occurred in areas of dense LiDAR coverage.

Connecticut Boundary

Title: Connecticut Boundary

Media: None

Source contribution:

This boundary layer is used to clip the terrain dataset to the state boundary when the terrain is displayed at large scales (specifically, at a maximum scale of 1:25,000).

Connecticut 1:125,000-scale boundary

Title: Connecticut 1:125,000-scale boundary

Map scale denominator: 1:125,000

Media: None

Source contribution:

This boundary layer is used to clip the terrain dataset to the state boundary when the terrain is displayed at small scales (specifically, at a minimum scale of 1:25,001).

+ Metadata Reference

Metadata Date

Dates associated with creating, updating and reviewing the metadata.

Last updated: 20110523

Metadata Point of Contact

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

Organization: State of Connecticut, Department of Energy and Environmental Protection

Person: Courtney Larson

Phone: 860-424-3540

Fax: 860-424-4058

Email: dep.gisdata@ct.gov

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

Address type: Unknown

Address:

79 Elm Street

City: Hartford

State or Province: CT

Postal code: 06106-5127

Country: USA

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 Standard for Digital Geospatial Metadata

Standard version: FGDC-STD-001-1998

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.