Product: These lidar data are processed Classified LAS 1.4 files, formatted to 1,577 individual 1250 ft x 1250 ft tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: Nantucket County Massachusetts, covering approximately 91 square miles. Dataset Description: The Nantucket project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011), State Plane, Feet and vertical datum of NAVD88 (GEOID12B), Feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 1,577 individual 1250 ft x 1250 ft tiles, as tiled Intensity Rasters, and as tiled bare-earth DEM; all tiled to the same 1250 ft x 1250 ft schema. Ground Conditions: Lidar was collected in early to mid 2018, 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, Sanborn Map Company, Inc. established a total of 20 ground control points that were used to calibrate and validate the lidar to known ground locations established throughout the project area. In addition to these lidar point data, the bare earth Digital Elevation Models (DEM) created from the lidar point data are also available. These data are available for custom download at the link provided in the URL section of this metadata record. This data set is an LAZ (compressed LAS) format file containing LIDAR point cloud data.