National Elevation Dataset for Pennsylvania


Identification_Information:
Citation:
Citation_Information:
Originator:U.S. Geological Survey (USGS), EROS Data Center
Publication_Date:1999
Title:
National Elevation Dataset for Pennsylvania
Edition:1
Publication_Information:
Publication_Place:Sioux Falls, SD
Publisher:U.S. Geological Survey
Online_Linkage: ftp://www.pasda.psu.edu/pub/pasda/ned
Description:
Abstract:
The U.S. Geological Survey has developed a National Elevation Dataset (NED). 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.
NED files are available on CD from the EROS data center as 1x1 degree tiles.  For online distribution the files on PASDA have been aggregated by county and projected into the Albers Equal Area projection.
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:
Range_of_Dates/Times:
Beginning_Date:19990201
Ending_Date:19990824
Currentness_Reference:
publication date
Status:
Progress:Complete
Maintenance_and_Update_Frequency:As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate:-77.471603
East_Bounding_Coordinate:-76.958397
North_Bounding_Coordinate:40.069698
South_Bounding_Coordinate:39.719891
Keywords:
Theme:
Theme_Keyword_Thesaurus:ISO 19115 Topic Categories
Theme_Keyword:7.5-MINUTE DEM
Theme_Keyword:CARTOGRAPHY
Theme_Keyword:DEM
Theme_Keyword:DIGITAL ELEVATION MODEL
Theme_Keyword:DIGITAL MAPPING
Theme_Keyword:EARTH SCIENCE
Theme_Keyword:EDC
Theme_Keyword:EROS
Theme_Keyword:GEODATA
Theme_Keyword:GIS
Theme_Keyword:LAND SURFACE
Theme_Keyword:LANDFORMS
Theme_Keyword:MAPPING
Theme_Keyword:RASTER
Theme_Keyword:TERRAIN ELEVATION
Theme_Keyword:TOPOGRAPHY
Theme_Keyword:USGS
Theme_Keyword:Elevation
Place:
Place_Keyword_Thesaurus:GCMD Location Keywords
Place_Keyword:Pennsylvania
Access_Constraints:None
Use_Constraints:
For use at 1:24,000 or smaller scale.

For educational/demonstration purposes only.  The Originator, Publisher and Distributor exclude any and all implied warranties and make no warranty or representation with respect to the data files or accompanying documentation, including quality, performance, merchantability or fitness for a particular purpose. These data files and documentation are provided 'as is' and the User assumes the entire risk as to their quality and performance

These data are not to be redistributed for commercial profit.  Reproduction or redistribution of this digital data set without permission of the Originator/Publisher is expressly forbidden.  The Originator and Publisher should be clearly cited in any product derived from this data.  Any modifications to this data must be described in any digital or hardcopy product derived from this data.
Data_Set_Credit:
The National Elevation Database (NED) county files on PASDA are provided through the Pennsylvania Bureau of Topographic and Geologic Survey (PAGS).
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Data_Quality_Information:
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
A plan for assessing the overall accuracy of the National Elevation Dataset (NED) based on independent high-accuracy geodetic control is currently under development. The accuracy described will be in the terms used in the FGDC Content Standards for Framework Land Elevation Data . Accuracy will be determined and reported using the methodology specified in the FGDC National Standard for Spatial Data Accuracy.

Until an independent overall assessment of the accuracy of NED is completed, it is best to refer to published information on the accuracy of the source digital elevation models (DEM's) from which NED was assembled. The primary source data were the USGS 7.5-minute (30-meter or 10-meter resolution) DEM's. Gaps in the 7.5-minute DEM coverage were filled with data from USGS 30-minute (2-arc-second resolution) or 1-degree (3-arc-second resolution) DEM's. The USGS Data Users Guide 5 for DEM's (traditionally known as the "blue book"), last published in 1993, contains a general discussion of DEM accuracy and a brief description of the accuracy testing methodology.

The DEM data users guide also describes the classification levels of standard USGS DEM products. The level of a DEM is defined, in part, on the basis of its accuracy.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value:30
Horizontal_Positional_Accuracy_Explanation:
NED sources for Pennsylvania 30-meter and 10-meter resolution DEM data, 10-meter data was resampled to 30-meter resolution for assembly of the nationwide dataset.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator:U.S. Geological Survey
Publication_Date:1996
Title:
USGS 7.5 minute Digital Elevation Model Data
Publication_Information:
Publication_Place:Sioux Falls, South Dakota, USA
Publisher:U.S. Geological Survey
Source_Scale_Denominator:24000
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date:unknown
Source_Currentness_Reference:
ground condition
Source_Citation_Abbreviation:
DEM
Source_Contribution:
Initial elevation data
Source_Information:
Source_Citation:
Citation_Information:
Originator:Pennsylvania Department of Transportation, Bureau of Planning and Research, Cartographic Information Division
Publication_Date:2004
Title:
Pennsylvania County Boundaries, 2004
Publication_Information:
Publication_Place:Harrisburg, PA
Publisher:Pennsylvania Dept. of Transportation
Online_Linkage: http://www.pasda.psu.edu/documents.cgi/padot/boundary_layers/padot-county_2004.xml
Source_Scale_Denominator:24000
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date:Unknown
Source_Currentness_Reference:
ground condition
Source_Citation_Abbreviation:
countbnd
Source_Contribution:
boundaries for clipping
Process_Step:
Process_Description:
USGS identified existing DEM data at the highest available resolution.  The majority is 30-meter 1:24000 scale data with 10-meter data used where available for the conterminous U.S.  Data was projected into geographic decimal degrees and datums were transformed to NAD83 and NAVD88.  Data with a horizontal resolution finer than 30-meters was resampled to 30-meter resolution before merging into the national dataset. All elevation units were converted to decimal meters.  Procedures were applied to correct and/or minimize artifacts found in the source DEM. 1x1 degree tiles were created and edge of 7.5 minute sources were matched.  These 1x1 degree tiles were merged to create two grid files that covered the entire state of Pennsylvania. A more detailed explanation of these processes performed at USGS can be found at: http://gisdata.usgs.gov/NED/default.asp.
Source_Used_Citation_Abbreviation:
DEM
Process_Date:1999
Process_Step:
Process_Description:
NED files were acquired as 1 x 1 degree ARC/INFO grids from USGS were merged to create two grids covering the Pennsylvania.
Process_Date:1999
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:U.S. Geological Survey
Process_Step:
Process_Description:
GRID files obtained on CD-ROM from USGS were merged to create a single GRID layer. This layer was clipped to the state boundary and cells falling outside the state boundary set to 'no data'. 
Process_Date:1999
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:Pa. Bureau of Topographic and Geologic Survey
Process_Step:
Process_Description:
Some anomalously high elevation values due to incorrect conversion of vertical units in the original USGS process were corrected at PaBTGS.  These areas were primarily in Butler County. 
Process_Date:2003
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:Pa. Bureau of Topographic and Geologic Survey
Process_Step:
Process_Description:
State wide corrected GRID layer from PaBTGS was clipped into county files, converted to DEM format and packaged for download. 
Source_Used_Citation_Abbreviation:
countbnd
Process_Date:200404
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:PASDA
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Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method:Raster
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Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name:Albers Conical Equal Area
Albers_Conical_Equal_Area:
Albers Conical Equal Area
Standard_Parallel:40
Standard_Parallel:42
Longitude_of_Central_Meridian:-78
Latitude_of_Projection_Origin:39
False_Easting:0
False_Northing:0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method:Coordinate Pair
Coordinate_Representation:
Abscissa_Resolution:30
Ordinate_Resolution:30
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:298.257
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name:North American Vertical Datum of 1988
Altitude_Distance_Units:meters
Altitude_Encoding_Method:Explicit elevation coordinate included with horizontal coordinates
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:Pennsylvania Spatial Data Access (PASDA)
Contact_Address:
Address_Type:mailing address
Address:
115 Land and Water Building
City:University Park
State_or_Province:PA
Postal_Code:16802
Country:USA
Contact_Voice_Telephone:(814) 865 - 8792
Contact_Electronic_Mail_Address:pasda@psu.edu
Resource_Description:downloadabledata
Distribution_Liability:
The USER shall indemnify, save harmless, and, if requested, defend those parties involved with the development and distribution of this data, their officers, agents, and employees from and against any suits, claims, or actions for injury, death, or property damage arising out of the use of or any defect in the FILES or any accompanying documentation. Those parties involved with the development and distribution excluded any and all implied warranties, including warranties or merchantability and fitness for a particular purpose and makes no warranty or representation, either express or implied, with respect to the FILES or accompanying documentation, including its quality, performance, merchantability, or fitness for a particular purpose. The FILES and documentation are provided "as is" and the USER assumes the entire risk as to its quality and performance. Those parties involved with the development and distribution of this data will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of the use or inability to use the FILES or any accompanying documentation.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name:DEM
File_Decompression_Technique:zip
Transfer_Size:2-8 MB
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: ftp://www.pasda.psu.edu/pub/pasda/ned/nedc-adams.zip
Access_Instructions:
http://www.pasda.psu.edu
Fees:none
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:EROS Data Center
Contact_Person:Customer Services Representative
Contact_Address:
Address_Type:mailing and physical address
Address:
U.S. Geological Survey EROS Data Center
City:Sioux Falls
State_or_Province:SD
Postal_Code:57198
Country:USA
Contact_Voice_Telephone:605-594-6151
Contact_Facsimile_Telephone:605-594-6589
Contact_Electronic_Mail_Address:custserv@edcmail.cr.usgs.gov
Resource_Description:National Elevation Database (NED) by county
Distribution_Liability:
Although these data have been processed successfully on a computer system at the U.S. Geological Survey, EROS Data Center, no warranty expressed or implied is made by either regarding the utility of the data on any system, nor shall the act of distribution constitute any such warranty. The USGS will warrant the delivery of this product in computer-readable format and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer peripherals, or when the physical medium is delivered in damaged condition. Requests for adjustments of credit must be made within 90 days from the date of this shipment from the ordering site.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name:Arc Grid
Format_Information_Content:
NED is produced in this format. Some other software packages can read the Arc Grid format.  Customers who specify Arc Grid will be delivered a workspace. The  work space is not tarred or gzipped.
File_Decompression_Technique:none
Digital_Form:
Digital_Transfer_Information:
Format_Name:GRIDFLOAT
Format_Information_Content:
GRIDFLOAT is a non-proprietary format made by running the GRIDFLOAT command in Arc. It is essentially a floating point binary data file with accompanying ASCII descriptor files.
Digital_Form:
Digital_Transfer_Information:
Format_Name:BIL
Format_Information_Content:
BIL is a non-proprietary format made by running the GRIDIMAGE command in Arc. It is essentially an integer binary data file with accompanying ASCII descriptor files.
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: http://seamless.usgs.gov
Offline_Option:
Offline_Media:CD-R
Fees:$45 per order plus $32 per CD
Ordering_Instructions:
See: http://gisdata.usgs.gov/NED/default.asp
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Metadata_Reference_Information:
Metadata_Date:19990211
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:Pennsylvania Spatial Data Access (PASDA)
Contact_Position:Metadata Coordinator
Contact_Address:
Address_Type:mailing address
Address:
115 Land and Water Building
City:University Park
State_or_Province:PA
Postal_Code:16802
Country:USA
Contact_Voice_Telephone:814-865-8792
Contact_Electronic_Mail_Address:pasda@psu.edu
Metadata_Standard_Name:FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version:FGDC-STD-001-1998
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