ElevationDEM_DEM24

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:

Vermont Center for Geographic Information, Inc., U.S. Geological Survey (USGS), EROS Data Center

Publication_Date: 20021024

Publication_Time: unknown

Title: ElevationDEM_DEM24

Edition: 2002

Geospatial_Data_Presentation_Form: raster digital data

Series_Information:

Series_Name: USGS National Elevation Dataset (NED) 7.5' DEM - single file

Issue_Identification: 2002

Publication_Information:

Publication_Place: Sioux Falls, SD

Publisher: U.S. Geological Survey

Other_Citation_Details: ElevationDEM_DEM24

Description:

Abstract:

The U.S. Geological Survey has developed a National Elevation Database (NED). VCGI has extracted a portion of the NED for Vermont and re-projected the file into Vermont State Plane Meters NAD83 (vertical units in feet). The NED is a seamless mosaic of best-available elevation data. The 7.5-minute elevation data for the conterminous United States are the primary initial source data. In addition to the availability of complete 7.5-minute data, efficient processing methods were developed to filter production artifacts in the existing data, convert to the NAD83 datum, edge-match, and fill slivers of missing data at quadrangle seams. One of the effects of the NED processing steps is a much-improved base of elevation data for calculating slope and hydrologic derivatives.

Purpose:

Geospatial elevation data are utilized by the scientific and resource management communities for global change research, hydrologic modeling, resource monitoring, mapping, and visualization applications.

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 20021024

Time_of_Day: Unknown

Currentness_Reference: Publication Date

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As new data becomes available

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -73.454162

East_Bounding_Coordinate: -71.465281

North_Bounding_Coordinate: 45.018361

South_Bounding_Coordinate: 42.722789

Keywords:

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category

Theme_Keyword: elevation

Theme:

Theme_Keyword_Thesaurus: None

Theme_Keyword: USGS 7.5 minute Digital Elevation Model data - single file

Theme_Keyword: elevation

Theme_Keyword: terrain

Theme_Keyword: DEM

Theme_Keyword: topographic

Theme_Keyword: topography

Place:

Place_Keyword_Thesaurus: None

Place_Keyword: Vermont

Access_Constraints:

VCGI and the State of VT make no representations of any kind, including but not limited to the warranties of merchantability or fitness for a particular use, nor are any such warranties to be implied with respect to the data.

Use_Constraints:

No assessment of the accuracy of DEM data or data products has been made by VCGI. Data users should assess DEM data products for appropriate use in a given project.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: VT Center for Geographic Information

Contact_Address:

Address_Type: Mailing and Physical Address

Address: 1 National Life Dr, Dewey Building, 2nd Floor

City: Montpelier

State_or_Province: VT

Postal_Code: 05620-2001

Country: USA

Contact_Voice_Telephone: (802) 585-0820

Contact_TDD/TTY_Telephone: None

Contact_Facsimile_Telephone:

Contact_Electronic_Mail_Address: vcgi@vermont.gov

Hours_of_Service: 9am - 5pm, M-F

Data_Set_Credit: Eric Pyle, VCGI

Security_Information:

Security_Classification_System: N/A

Security_Classification: Unclassified

Security_Handling_Description: No Security Considerations

Native_Data_Set_Environment: A/I GRID only

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Refer to USGS NED web site at <http://ned.usgs.gov> for more information.

Logical_Consistency_Report:

No assessment of the accuracy of DEM data or data products has been made by VCGI. Refer to USGS NED web site at <http://ned.usgs.gov> for more information.

Completeness_Report: Refer to Vertical_Positional_Accuracy_Report.

Completeness_Report:

Datasets contain complete coverage of each individual data collection area (extent) - see the VCGI LiDAR data product web page for details - https://vcgi.vermont.gov/data-and-programs/lidar-program.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report: Refer to Vertical_Positional_Accuracy_Report.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

As noted ElevationDEM_DEM24 was generated from the USGS NED, which was created from 7.5 minute USGS DEMs. The accuracy of a 7.5 minute DEM is dependent upon the level of detail of the source data and the grid spacing used to sample the source. 7.5 minute DEMs have a grid spacing of 30 meters. The USGS determines 7.5 minute DEM accuracy by comparing "true" elevations with those interpolated during the DEM data development process. Refer to USGS NED web site at <http://ned.usgs.gov> for more information. Level-1, Level-2, andLevel-3. Data available for Vermont consists of Level-1 and Level-2 data only. Data consists of data derived from scanning National High-Altitude Photography Program, National Aerial Photography Program, or equivalent photography. A vertical RMSE of 7 meters is the desired accuracy. A maximum RMSE of 15 meters is permitted for this category. "Systematic errors within the stated accuracy standards are tolerated at this level." These are DEMs which have been processed or smoothed for consistency or edited to remove systematic errors. An RMSE of one-half contour interval is the maximum permitted. There should be no errors greater than one contour interval. The USGS periodically updates the accuracy of DEMs and integrates these into the NED. As VCGI obtains revised versions, their availability will be noted in an update record for this documentation.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Eric Pyle

Publication_Date: 19981119

Publication_Time: unknown

Title: ElevationDEM_DEM24

Edition: 2002

Geospatial_Data_Presentation_Form: vector digital data

Series_Information:

Series_Name: USGS 7.5 minute Digital Elevation Model data - single file

Issue_Identification: 1.1

Publication_Information:

Publication_Place: Waterbury VT 05676

Publisher: Eric Pyle

Other_Citation_Details: ElevationDEM_DEM24

Source_Scale_Denominator: 1:24,000,1:25000

Type_of_Source_Media: disc

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 20021024

Time_of_Day: Unknown

Source_Currentness_Reference: Publication Date

Source_Citation_Abbreviation: ElevationDEM_DEM24

Source_Contribution: Eric Pyle

Process_Step:

Process_Description:

Eric Pyle created GRID. Steve Sharp developed documentation and made available on website. - Operator = Steve Sharp, VCGI

Process_Date: 19981119

Process_Step:

Process_Description:

Updated ElevationDEM_DEM24 using the National Elevation Database DEM (NED), with Vermont extracted by bounding box. Data is in Vermont State Plane meters, NAD83, zunits feet. Reprojected from the data supplied on the NED CD by Eric Pyle. Processing included selecting out the Vermont region, reprojecting with an output cell size of 30 meters and bilinear interpolation, and conversion of zunits from meters to feet. 30 meters was chosen for the cell size because it is the conventional cell size for this class of DEM data, and is close to the size of the original grid cells (1 arc-second) when reprojected to Vt. Stateplane. Compressed, and loaded into VGIS Data Warehouse by Steve Sharp.

Process_Date: 19990929

Process_Step:

Process_Description:

Recently discovered that previous ElevationDEM_DEM24 data had South West shift in data. The true "Z", i.e., elevation value, for a point was actually approx. 40 meters South West. Clipped out the National Elevation Database DEM (NED), with a outline of the state of Vermont that was buffered 2,000 meters. Data is in Vermont State Plane meters, NAD83, zunits feet. Reprojected from the data supplied on the NED CD by Mike Brouillette. Processing included selecting out the Vermont region, reprojected using the bilinear interpolation option, and converted zunits from meters to feet. Compressed, and loaded into VGIS Data Warehouse by Mike Brouillette.

Process_Date: 20011114

Process_Step:

Process_Description:

Created new ElevationDEM_DEM24 NED based grid, from original composite grid in spherical coordinates (Geographic), to have a 30m cell size. Grid extent is still the outline of the state of Vermont buffered 2,000 meters. Data is in Vermont State Plane meters, NAD83, zunits feet. Reprojected using the bilinear interpolation option. Zunits are still in feet. Compressed, and loaded into VGIS Data Warehouse by Mike Brouillette.

Process_Date: 20021024

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference: GRID

Direct_Spatial_Reference_Method: Raster

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: State Plane Coordinate System

State_Plane_Coordinate_System:

SPCS_Zone_Identifier: 4400 (USGS), 5526 (ESRI)

Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.99996

Longitude_of_Central_Meridian: -072.500000

Latitude_of_Projection_Origin: +42.500000

False_Easting: 0.001

False_Northing: 0.001

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.001

Ordinate_Resolution: 0.001

Planar_Distance_Units: Meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137

Denominator_of_Flattening_Ratio: 1 / 298.25722210

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: VT Center for Geographic Information

Contact_Address:

Address_Type: Mailing and Physical Address

Address: 1 National Life Dr, Dewey Building, 2nd Floor

City: Montpelier

State_or_Province: VT

Postal_Code: 05620-2001

Country: USA

Contact_Voice_Telephone: (802) 585-0820

Contact_TDD/TTY_Telephone: None

Contact_Facsimile_Telephone:

Contact_Electronic_Mail_Address: vcgi@vermont.gov

Hours_of_Service: 9am - 5pm, M-F

Resource_Description: ElevationDEM_DEM24

Distribution_Liability:

VCGI and the State of Vermont make no representations of any kind, including but not limited to the warranties of merchantability or fitness for a particular use, nor are any such warranties to be implied with respect to the data.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: ASC

Format_Specification: ESRI ASCII Grid format

Format_Information_Content: geospatial data

File_Decompression_Technique: ZIP decompression software

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

https://maps.vcgi.vermont.gov/gisdata/vcgi/packaged_zips/ElevationDEM_DEM24.zip

Access_Instructions: Download from web site.

Offline_Option:

Offline_Media: USB drive

Fees:

No charge when downloading from the internet, and when no custom processing is required.

Ordering_Instructions: Send an email describing data request to vcgi@vermont.gov

Turnaround: About 5 days.

Custom_Order_Process: Send an email describing data request to vcgi@vermont.gov

Technical_Prerequisites: GIS Software

Available_Time_Period:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 20001023

Time_of_Day: Unknown

Metadata_Reference_Information:

Metadata_Date: 20021024

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: VT Center for Geographic Information

Contact_Person: GIS Database Administrator

Contact_Address:

Address_Type: Mailing and Physical Address

Address: 1 National Life Dr, Dewey Building, 2nd Floor

City: Montpelier

State_or_Province: VT

Postal_Code: 05620-2001

Country: USA

Contact_Voice_Telephone: (802) 585-0820

Contact_TDD/TTY_Telephone: None

Contact_Facsimile_Telephone:

Metadata_Standard_Name: FGDC Content Standards for Digital Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: Local time

Metadata_Access_Constraints: None

Metadata_Use_Constraints: None

Metadata_Security_Information:

Metadata_Security_Classification_System: N/A

Metadata_Security_Classification: Unclassified

Metadata_Security_Handling_Description: No security considerations