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2011 - 2012 New York State Department of Environmental Conservation (NYSDEC) Lidar: Coastal New York (Long Island and along the Hudson River)
browse graphic Light Detection and Ranging (LiDAR) data is remotely sensed high-resolution elevation data collected by an airborne collection platform. This LiDAR dataset is a survey of areas of coastal New York, including Long Island, eastern Westchester, and the tidal extents of the Hudson River. The project area consists of approximately 950 square miles. The project design of the LiDAR data acquisition was developed to support a nominal post spacing of 1.0 meter or better (1.0 meter GSD). GMR Aerial Surveys Inc. d/b/a Photo Science, Inc. acquired 740 flight lines in 63 lifts between November 2011 and April 2012, while no snow was on the ground, rivers were at or below normal levels, no strong onshore winds, high waves, floods, or other anomalous weather conditions. Specified areas of the project were collected at a tide stage where water levels are at least 1-foot below mean sea level (MSL). This collection was a joint effort by the NOAA Coastal Services Center (CSC) and the New York State Department of Environmental Conservation. The data collection was performed with three Cessna 206 single engine aircrafts, utilizing Optech Gemini sensors; collecting multiple return x, y, and z as well as intensity data. The data were classified as Unclassified (1), Ground (2), Low Point (Noise) (7), Water (9), Breakline Edge (10), Withheld (11), Tidal Water (14), Overlap Default (17), and Overlap Ground (18), Overlap Water (25), and Overlap Tidal Water (30). Upon receipt, the NOAA Coastal Services Center (CSC), for data storage and Digital Coast provisioning purposes, converted these classifications to the following: 1 - Unclassified 2 - Ground 7 - Low Point (Noise) 9 - Water NOAA tide gauges were used as the basis for flight planning the tidally coordinated areas. Some areas were collected using tidal restraints as listed below: Tidal Wetlands and tributary mouths selected for tidal coordination at Mean Sea Level (MSL) minus 1 foot were: Rondout Creek Outlet; Vanderburg Cove, Moodna Creek, Constitution Marsh, Iona Marsh, Annsville Creek, Croton River Outlet, Marlboro Marsh, Manitou Marsh, Fishkill Creek Outlet, and Wappingers Creek Outlet. The Upper Hudson area from North of Goose Island was also collected to the same specification. Tidal Wetlands and tributary mouths selected for tidal coordination at Mean Sea Level (MSL) were: Haverstraw at Minisceongo Creek and Piedmont Marsh. The remainder of the project area had no tidal restrictions for collection. In order to post process the LiDAR data to meet task order specifications, Photo Science, Inc. established a total of 81 control points that were used to calibrate the LiDAR to known ground locations established throughout the New York project area. Trimble R8-3 GNSS receivers were used to complete the collection. Real Time Kinematic (RTK) survey methodology was typically performed using the New York State Spatial Reference Network (NYSNet), a CORS/Real Time GPS Network. Additionally, control values from various other projects completed by Photo Science in and around the project area, were used as supplemental control points to assist in the calibration of the LiDAR dataset. The dataset was developed based on a horizontal projection/datum of UTM NAD83 (NSRS2007), UTM Zone 18, meters and vertical datum of NAVD1988 (GEOID09), meters. Upon receipt, for data storage and Digital Coast provisioning purposes, the NOAA Coastal Services Center converted the data to GRS80 Ellipsoid (GEOID09) heights, to geographic (NAD83, NSRS2007) coordinates, and from las format to laz format. LiDAR data were collected in RAW flightline swath format, processed to create Classified LAS 1.2 Files formatted to 2093 individual 750m x 750m tiles, Hydro Flattening Breaklines in Esri 1.0 meter gridded V-Datum ESRI Grid files formatted to the same 3000m x 3000m tile schema. LiDAR Data was originally delivered to NOAA/Dewberry for quality control validation under Delivery Lots 1 and 2. The lineage (data quality), positional, content (completeness), attribution, logical consistency, and accuracies of all digital elevation data produced conform to the specifications stipulated in NOAA Task Order EA133C11CQ0009 - T011.