Pennsylvania North Central Lidar QL1 ; Classified Point Cloud

• 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:20210122

Title:

Pennsylvania North Central Lidar QL1 ; Classified Point Cloud

Geospatial_Data_Presentation_Form:LiDAR point cloud

Description:

Abstract:

       Product: These lidar data are processed Classified LAS 1.4 files, formatted to 95 individual 5,000 ft x 5,000 ft tiles; used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.
       Geographic Extent: 4 counties in Pennsylvania, covering approximately 85 total square miles.
       Dataset Description: The Pennsylvania North Central Lidar QL1  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, Version 1.3. The data were developed based on a horizontal projection/datum of NAD 1983 StatePlane Pennsylvania North FIPS 3701 Feet, Foot US and vertical datum of NAVD88 GEOID12b, Foot US. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 95 individual 5,000 ft x 5,000 ft tiles; and as 31 10,000 ft x 10,000 ft 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 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 1.25 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:

Contract No. G16PC00016, Task Order No. 140G0219F0103; CONTRACTOR: Quantum Spatial, Inc.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date:20190323

Ending_Date:20190327

Currentness_Reference:

Ground condition

Status:

Progress:Complete

Maintenance_and_Update_Frequency:None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate:-78.9587933572

East_Bounding_Coordinate:-78.7280576927

North_Bounding_Coordinate:42.0150217211

South_Bounding_Coordinate:41.3543495486

Keywords:

Theme:

Theme_Keyword_Thesaurus:None

Theme_Keyword:Model

Theme_Keyword:LAS Point Cloud

Theme_Keyword:Remote Sensing

Theme_Keyword:Elevation Data

Theme_Keyword:LiDAR

Place:

Place_Keyword_Thesaurus:None

Place_Keyword:Pennsylvania

Place_Keyword:Cattaraugus County

Place_Keyword:Elk County

Place_Keyword:McKean County

Place_Keyword:Warren 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.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:Quantum Spatial, Inc.

Contact_Person:John DiGiovanni

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

Contact_Electronic_Mail_Address:jdigiovanni@quantumspatial.com

Hours_of_Service:Monday through Friday 8:00 AM to 5:00 PM (Eastern Time)

Contact Instructions:

If unable to reach the contact by telephone, please send an email. You should get a response within 24 hours.

Native_Data_Set_Environment:

MicroStation Connect; TerraScan Version 20.011; TerraModeler Version 20.004; GeoCue Version 2017.1.14.1; Esri ArcGIS 10.6; Global Mapper 19/20; Leica Cloud Pro 1.2.4; Windows 10 Operating System \\point_cloud\tilecls\*.las

Data_Quality_Information:

Logical_Consistency_Report:

Data cover the entire area specified for this project.

Completeness_Report:

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and the data pass Non-Vegetated Vertical Accuracy specifications.

Positional_Accuracy:

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 320 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:0.134

Vertical_Positional_Accuracy_Explanation:

            Tested 0.134 meters NVA at a 95% confidence level using 320 independent survey points located in open terrain. The survey check points were distributed throughout the project area. The 320 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 0.068 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.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator:Quantum Spatial, Inc.

Publication_Date:20210122

Title:

Ground Control for the Pennsylvania North Central Lidar QL1 Project

Geospatial_Data_Presentation_Form:Vector digital data and tabular digital data

Publication_Information:

Publication_Place:Quantum Spatial, Inc.

Publisher:Quantum Spatial, Inc.

Other_Citation_Details:

None

Type_of_Source_Media:external hard drive

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date:20190729

Source_Currentness_Reference:

Ground condition

Source_Citation_Abbreviation:

Pennsylvania_North_Central_Lidar_QL1__gnd_ctrl

Source_Contribution:

This data source was used (along with airborne GPS/IMU data) to georeference the LiDAR point cloud data.

Process_Step:

Process_Description:

Raw Data and Boresight Processing: The boresight for each lift was done individually as the solution may change slightly from lift to lift. The following steps describe the Raw Data Processing and Boresight process: 1) Technicians processed the raw data to LAS format flight lines using the final GPS/IMU solution. This LAS data set was used as source data for boresight. 2) Technicians first used Quantum Spatial, Inc. proprietary and commercial software to calculate initial boresight adjustment angles based on sample areas selected in the lift. These areas cover calibration flight lines collected in the lift, cross tie, and production flight lines. These areas are well distributed in the lift coverage and cover multiple terrain types that are necessary for boresight angle calculation. The technicians then analyzed the results and made any necessary additional adjustment until it was acceptable for the selected areas. 3) Once the boresight angle calculation was completed for the selected areas, the adjusted settings were applied to all of the flight lines of the lift and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight line overlaps matched for the entire lift and adjusted as necessary until the results met the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was less than or equal to 7 cm RMSEz within individual swaths and less than or equal to 10 cm RMSEz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the boresighted flight lines against the surveyed checkpoints after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met.

Source_Used_Citation_Abbreviation:

Pennsylvania_North_Central_Lidar_QL1__gnd_ctrl

Process_Date:2021

Process_Step:

Process_Description:

LAS Point Classification: The point classification was performed as described below. The bare earth surface was manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface was finalized, it was then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) LiDAR data inside of the Lake Pond and Double Line Drain hydro-flattened breaklines were then classified to Water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 1 meter was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 20). All Lake Pond Island and Double Line Drain Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight line data to approved classes. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. Due to software limitations within TerraScan, these classes were used to trip the withheld bit within various software packages. These processes were reviewed and accepted through numerous conference calls and pilot study areas. All data were manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper was used as a final check of the bare earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for both the All Point Cloud Data and the Bare Earth. Quantum Spatial, Inc. proprietary software was used to perform final statistical analysis of the classes in the LAS files, on a per tile level to verify final classification metrics and full LAS header information.

Process_Date:2021

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method:Point

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:3701

Lambert_Conformal_Conic:

Standard_Parallel:40.8833333333

Standard_Parallel:41.95

Longitude_of_Central_Meridian:-77

Latitude_of_Projection_Origin:40.1666666667

False_Easting:1968500

False_Northing:0.0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method:coordinate pair

Coordinate_Representation:

Abscissa_Resolution:0.001

Ordinate_Resolution:0.001

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:20210122

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.