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USGS PA Allentown OrthoLidar 1 D24; Breaklines

2025 - U S Geological Survey


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ADDITIONAL RESOURCES
Web Application: https://www.pasda.psu.edu/download/allentown/LiDAR2025/PA_AllentownOrthoLidar_1_D24/metadata/reports/
ABSTRACT
Breakline data is used to hydroflatten the DEMs created for the USGS_PA_AllentownOrthoLidar_1_D24 project. Breaklines are reviewed against LiDAR intensity imagery to verify completeness of capture.Geographic Extent: 1 counties in Pennsylvania, covering approximately 28 total square miles.Dataset Description: The USGS_PA_AllentownOrthoLidar_1_D24 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, 2023 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 129 individual 2500 ft x 2500 ft tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 2500 ft x 2500 ft schema. Continuous breaklines were produced in Esri file geodatabase format.Ground Conditions: LiDAR was collected in fall 2024, 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 5 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 65 independent accuracy checkpoints, 33 in Bare Earth and Urban landcovers (33 NVA points), 32 in Tall Weeds categories (32 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.