Product: These are Digital Elevation Model (DEM) data for Maine as part of the required deliverables for the ME_SouthCentral_B22, Work Unit 230147 project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 1 meter hydro-flattened Raster DEM. Geographic Extent: 11 counties in Maine, covering approximately 2505 total square miles. Dataset Description: The ME_SouthCentral_B22, Work Unit 230147 project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.46 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, 2021 Rev. A. The data were developed based on a horizontal projection/datum of NAD 1983 2011 UTM Zone 19N, Meter and vertical datum of NAVD88 Geoid 18, Meter. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 3106 individual 1500 m x 1500 m tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1500 m x 1500 m schema. Continuous breaklines were produced in Esri file geodatabase format. Ground Conditions: LiDAR was collected in spring 2022, 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 63 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 147 independent accuracy checkpoints, 83 in Bare Earth and Urban landcovers (83 NVA points), 64 in Tall Weeds categories (64 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

Product: These are Digital Elevation Model (DEM) data for Maine as part of the required deliverables for the ME_SouthCentral_B22, Work Unit 230147 project. Class 2 (ground) LiDAR points in conjunction with the hydro breaklines were used to create a 1 meter hydro-flattened Raster DEM. Geographic Extent: 11 counties in Maine, covering approximately 2505 total square miles. Dataset Description: The ME_SouthCentral_B22, Work Unit 230147 project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.46 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, 2021 Rev. A. The data were developed based on a horizontal projection/datum of NAD 1983 2011 UTM Zone 19N, Meter and vertical datum of NAVD88 Geoid 18, Meter. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 3106 individual 1500 m x 1500 m tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1500 m x 1500 m schema. Continuous breaklines were produced in Esri file geodatabase format. Ground Conditions: LiDAR was collected in spring 2022, 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 63 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 147 independent accuracy checkpoints, 83 in Bare Earth and Urban landcovers (83 NVA points), 64 in Tall Weeds categories (64 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.