PA_17County_2024; DEM


Identification_Information:
Citation:
Citation_Information:
Originator:NV5 Geospatial
Publication_Date:20260918
Title:
PA_17County_2024; DEM
Geospatial_Data_Presentation_Form:Raster digital data
Description:
Abstract:
       Product: These are Digital Elevation Model (DEM) data for Pennsylvania as part of the required deliverables for the PA_17County_2024 project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 2 foot hydro-flattened Raster DEM.
       Geographic Extent: 44 counties in Pennsylvania, covering approximately 8751 total square miles.
       Dataset Description: The PA_17County_2024 project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, 2024 Rev. A. The data were developed based on a horizontal projection/datum of NAD 1983 2011 StatePlane Pennsylvania South FIPS 3702 Ft US, Foot US and vertical datum of NAVD88 Geoid 18, Foot US. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 37924 individual 2500 ft x 2500 ft tiles. All rasters were tiled to a 5000 ft x 5000 ft schema. Continuous breaklines were produced in shapefile format.
       Ground Conditions: LiDAR was collected in spring 2024 through spring 2025, while no snow was on the ground and rivers were at or below normal levels. In order to post process the LiDAR data to meet task order specifications and meet ASPRS vertical accuracy guidelines, NV5 Geospatial utilized a total of 119 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 153 independent accuracy checkpoints, 123 in Bare Earth and Urban landcovers (123 NVA points), 30 in Tall Weeds categories (30 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.
Purpose:
To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create intensity images, breaklines and raster DEMs. The purpose of these LiDAR data was to produce high accuracy 3D hydro-flattened digital elevation models (DEMs) with a 2 foot cell size. These raw LiDAR point cloud data were used to create classified LiDAR LAS files, intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.
Supplemental_Information:
Raster File Type = GeoTIFF; Bit Depth/Pixel Type = 32-bit float; Raster Cell Size = 2 foot; Interpolation or Resampling Technique = Triangulated Irregular Network (TIN), Linear Interpolation, Proprietary; Required Vertical Accuracy = 0.196
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date:20240414
Ending_Date:20250401
Currentness_Reference:
Ground condition
Status:
Progress:Complete
Maintenance_and_Update_Frequency:None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate:-80.3870574755
East_Bounding_Coordinate:-74.6861195718
North_Bounding_Coordinate:40.9666109895
South_Bounding_Coordinate:39.6780671516
Keywords:
Theme:
Theme_Keyword_Thesaurus:None
Theme_Keyword:Model
Theme_Keyword:Raster
Theme_Keyword:DEM
Theme_Keyword:Remote Sensing
Theme_Keyword:Elevation Data
Theme_Keyword:Lidar
Place:
Place_Keyword_Thesaurus:None
Place_Keyword:Pennsylvania
Place_Keyword:Adams County
Place_Keyword:Allegheny County
Place_Keyword:Armstrong County
Place_Keyword:Baltimore County
Place_Keyword:Beaver County
Place_Keyword:Berks County
Place_Keyword:Bucks County
Place_Keyword:Burlington County
Place_Keyword:Butler County
Place_Keyword:Camden County
Place_Keyword:Carbon County
Place_Keyword:Carroll County
Place_Keyword:Cecil County
Place_Keyword:Chester County
Place_Keyword:Columbia County
Place_Keyword:Cumberland County
Place_Keyword:Dauphin County
Place_Keyword:Delaware County
Place_Keyword:Franklin County
Place_Keyword:Frederick County
Place_Keyword:Fulton County
Place_Keyword:Gloucester County
Place_Keyword:Harford County
Place_Keyword:Hunterdon County
Place_Keyword:Huntingdon County
Place_Keyword:Juniata County
Place_Keyword:Lancaster County
Place_Keyword:Lebanon County
Place_Keyword:Lehigh County
Place_Keyword:Luzerne County
Place_Keyword:Mercer County
Place_Keyword:Montgomery County
Place_Keyword:New Castle County
Place_Keyword:Northampton County
Place_Keyword:Northumberland County
Place_Keyword:Perry County
Place_Keyword:Philadelphia County
Place_Keyword:Salem County
Place_Keyword:Schuylkill County
Place_Keyword:Warren County
Place_Keyword:Washington County
Place_Keyword:Westmoreland County
Place_Keyword:York County
Access_Constraints:No restrictions apply to these data.
Use_Constraints:
None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of their limitations. Acknowledgement of the organization providing these data to the public would be appreciated for products derived from these data.
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Data_Quality_Information:
Logical_Consistency_Report:
Data cover the entire area specified for this project.
Completeness_Report:
Datasets contain complete coverage of tiles. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. There are no void areas or missing data. The raw point cloud is of good quality and data pass Non-Vegetated Vertical Accuracy specifications.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 18 (cm) RMSEh Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 33 cm at a 95% confidence level.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
          The specifications require that only nonvegetated vertical accuracy (NVA) be computed for raw LiDAR data swath files. The vertical accuracy was tested with 123 independent survey points located in open terrain. These check points were not used in the calibration or post processing of the LiDAR data. The survey check points were distributed throughout the project area.
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value:0.0547
Vertical_Positional_Accuracy_Explanation:
            Tested 0.0547 meters NVA at a 95% confidence level using 123 independent survey points located in open terrain. The survey check points were distributed throughout the project area. The 123 independent check points were surveyed using GPS techniques. See survey report for additional survey methodologies. Elevations from the unclassified LiDAR surface were measured for the x,y location of each checkpoint. Elevations interpolated from the LiDAR surface were then compared to the elevation values of the surveyed control points. The root mean square error vertical (RMSEz) was computed to be 0.0279 meters. AccuracyZ has been tested to meet 19.0 cm NVA at 95-percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using American Society of Photogrammetry and Remote Sensing (ASPRS) Guidelines.
Lineage:
Process_Step:
Process_Description:
Hydro-Flattened Raster DEM Processing: Class 2 (Ground) LiDAR points in conjunction with the hydro-breaklines were used to create a 2 foot hydro-flattened raster DEM. Using automated scripting routines in proprietary software, GeoTIFF files were created for each tile. Each surface was reviewed using Global Mapper to check for any surface anomalies or incorrect elevations found within the surface.
Process_Date:2026
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Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method:Raster
Raster_Object_Information:
Raster_Object_Type:Pixel
Row_Count:2500
Column_Count:2500
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Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name:State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier:3702
Lambert_Conformal_Conic:
Standard_Parallel:39.9333333333
Standard_Parallel:40.9666666667
Longitude_of_Central_Meridian:-77
Latitude_of_Projection_Origin:39.3333333333
False_Easting:1968500
False_Northing:0.0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method:coordinate pair
Coordinate_Representation:
Abscissa_Resolution:2.0
Ordinate_Resolution:2.0
Planar_Distance_Units:Foot US
Geodetic_Model:
Horizontal_Datum_Name:North American Datum of 1983 (2011)
Ellipsoid_Name:Geodetic Reference System 80
Semi-major_Axis:6378137.0
Denominator_of_Flattening_Ratio:298.257222101
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name:NAVD88 Geoid 18
Altitude_Resolution:0.001
Altitude_Distance_Units:Foot US
Altitude_Encoding_Method:Explicit elevation coordinate included with horizontal coordinates
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Organization:Pennsylvania Spatial Data Access (PASDA)
Contact_Address:
Address_Type:mailing address
Address:
115 Land and Water research building
City:University Park
State_or_Province:Pennsylvania
Postal_Code:16802
Country:United States
Contact_Voice_Telephone:814-865-8792
Contact_Electronic_Mail_Address:pasda@psu.edu
Resource_Description:Downloadable Data
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:
Transfer_Size:0.006
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Metadata_Reference_Information:
Metadata_Date:20260918
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:NV5 Geospatial
Contact_Address:
Address_Type:mailing and physical
Address:
523 Wellington Way
City:Lexington
State_or_Province:KY
Postal_Code:40503
Country:USA
Contact_Voice_Telephone:859-277-8700
Contact_Facsimile_Telephone:859-277-8901
Hours_of_Service:Monday through Friday 8:00 AM to 5:00 PM (Eastern Time)
Metadata_Standard_Name:FGDC Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version:FGDC-STD-001-1998
Metadata_Access_Constraints:None.
Metadata_Use_Constraints:
None.
Metadata_Security_Information:
Metadata_Security_Classification_System:None.
Metadata_Security_Classification:Unclassified
Metadata_Security_Handling_Description:
NONE
Metadata_Extensions:
Online_Linkage: None.
Profile_Name:None.
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