King CountyFor more information about this layer please see the GIS Data Catalog . All ground control monuments utilized for the PSLC King County Lidar dataset. Ground control monuments are used to provide redundant control within 13 nautical miles of mission areas for Lidar flights, as well as the collection of ground control points using real-time kinematic (RTK) and post-precessed kinematic (PPK) survey techniques. Data was processed in reference to NAD83 (CORS96), however the horizontal datum for this dataset is defined as NAD83 (HARN) as the difference is generally small and allows for greater ease of use with data in different datums. The vertical datum is NAVD88, Geoid 03, and the data is projected in Washington State Plane North. Units are in US Survey Feet. Quantum Spatial collected the PSLC King County LiDAR data for the Puget Sound LiDAR Consortium between 02/24/16 and 05/25/17.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/69dc43c462fc4c1a84e46e602658c3d6_0engKing County GIS Open DataPublicGround Control Monuments for 2016 King County/Puget Sound Lidar Consortium Lidar Project [Washington (State)--King County]Web servicesWashington (State)--King CountyWashington (State)2016