Pennsylvania North Central Lidar QL2; DEM

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

Identification_Information:

Citation:

Citation_Information:

Originator:Quantum Spatial, Inc.

Publication_Date:20210121

Title:

Pennsylvania North Central Lidar QL2; 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 Pennsylvania North Central Lidar QL2 project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 2.5 foot hydro-flattened Raster DEM.
       Geographic Extent: 35 counties in Pennsylvania, covering approximately 5922 total square miles.
       Dataset Description: The Pennsylvania North Central Lidar QL2 project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.71 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 1.3. The data were developed based on a horizontal projection/datum of NAD 1983 StatePlane Pennsylvania South FIPS 3702 Feet, Foot US and vertical datum of NAVD88 GEOID12B, Foot US. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 6,269 individual 5,000 ft x 5,000 ft tiles; 1651 individual 10,000 ft x 10,000 ft tiles, as tiled intensity imagery, and as tiled bare earth DEMs.Continuous breaklines were produced in Esri file geodatabase format.
       Ground Conditions: LiDAR was collected in spring and fall 2019, 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, Quantum Spatial, Inc. utilized a total of 326 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 546 independent accuracy checkpoints, 322 in Bare Earth and Urban landcovers (322 NVA points), 224 in Tall Weeds categories (224 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 2.5 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 = 2.5 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:20190323

Ending_Date:20191123

Currentness_Reference:

Ground condition

Status:

Progress:Complete

Maintenance_and_Update_Frequency:None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate:-78.8681408374

East_Bounding_Coordinate:-75.0269484434

North_Bounding_Coordinate:41.0352262248

South_Bounding_Coordinate:39.659011226

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:Allegany County

Place_Keyword:Bedford County

Place_Keyword:Berks County

Place_Keyword:Blair County

Place_Keyword:Bucks County

Place_Keyword:Cambria County

Place_Keyword:Carbon County

Place_Keyword:Cecil County

Place_Keyword:Centre County

Place_Keyword:Chester County

Place_Keyword:Clearfield County

Place_Keyword:Dauphin County

Place_Keyword:Franklin County

Place_Keyword:Fulton County

Place_Keyword:Harford County

Place_Keyword:Hunterdon County

Place_Keyword:Huntingdon County

Place_Keyword:Indiana County

Place_Keyword:Jefferson County

Place_Keyword:Juniata County

Place_Keyword:Lancaster County

Place_Keyword:Lebanon County

Place_Keyword:Lehigh County

Place_Keyword:Luzerne County

Place_Keyword:Mifflin County

Place_Keyword:Monroe County

Place_Keyword:Montgomery County

Place_Keyword:Morgan County

Place_Keyword:Northampton County

Place_Keyword:Schuylkill County

Place_Keyword:Somerset County

Place_Keyword:Union County

Place_Keyword:Warren County

Place_Keyword:Washington 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.

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:

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

          The project specifications require the accuracy (ACCz) of the derived DEM be calculated and reported in two ways: 1. The required NVA is: 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 10 cm in the "bare earth" and "urban" land cover classes. This is a required accuracy. The NVA was tested with 322 checkpoints located in bare earth and urban (non-vegetated) areas. 2. Vegetated Vertical Accuracy (VVA): VVA shall be reported for "tall weeds" land cover classes. The target VVA is: 29.4 cm at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for LiDAR Data, i.e., based on the 95th percentile error in all vegetated land cover classes combined. This is a target accuracy. The VVA was tested with 224 checkpoints located in forested and tall weeds (vegetated) areas. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy at 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value:0.098

Vertical_Positional_Accuracy_Explanation:

            Tested 0.098 meters NVA at a 95% confidence level using 322 independent survey points located in open terrain. The survey check points were distributed throughout the project area. The 322 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 elevations values of the surveyed control points. The root mean square error vertical (RMSEz) was computed to be 0.068 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.

Quantitative_Vertical_Positional_Accuracy_Assessment:

Vertical_Positional_Accuracy_Value:0.158

Vertical_Positional_Accuracy_Explanation:

            Tested 0.158 meters VVA was calculated using 224 checkpoints located in vegetation at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for LiDAR Data. Tested against the DEM.

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 2.5 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:2021

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method:Raster

Raster_Object_Information:

Raster_Object_Type:Pixel

Row_Count:4000

Column_Count:4000

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:2.5

Ordinate_Resolution:2.5

Planar_Distance_Units:Foot US

Geodetic_Model:

Horizontal_Datum_Name:D North American 1983

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 GEOID12B

Altitude_Resolution:0.001

Altitude_Distance_Units:Foot US

Altitude_Encoding_Method:Explicit elevation coordinate included with horizontal coordinates

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:Pennsylvania Spatial Data Access (PASDA)

Contact_Address:

Address_Type:mailing and physical address

Address:

115 Land and Water 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

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

Metadata_Reference_Information:

Metadata_Date:20210121

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:Quantum Spatial, Inc.

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.