Gateway NRA Post Sandy Lidar

These data were collected as a part of the Post Sandy effort to depict the elevations above and below the water in the NY coastal zone. This data set is a raster file of z values with 5655 columns and 4121 rows. The data set was extracted from a larger classified data set and only includes points classified as Ground, Model Key-point (mass point), Bathymetric Lidar Points, and Acoustic Bathymetry (bare earth) within the requested geographic bounds. These files contain classified topographic and bathymetric lidar data as unclassified valid topographic data (1) and valid topographic data classified as ground (2), Classes 1 and 2 are defined in accordance with the American Society for Photogrammetry and Remote Sensing (ASPRS) classification standards. The data were collected on November 16, 2012 and covers Gateway NRA. These data were collected by the Coastal Zone Mapping and Imaging Lidar (CZMIL) system. CZMIL integrates a lidar sensor with topographic and bathymetric capabilities, a digital camera and a hyperspectral imager on a single remote sensing platform for use in coastal mapping and charting activities. Native lidar data is not generally in a format accessible to most Geographic Information Systems (GIS). Specialized in-house and commercial software packages are used to process the native lidar data into 3-dimensional positions that can be imported into GIS software for visualization and further analysis. Horizontal positions, provided in decimal degrees of latitude and longitude, are referenced to the North American Datum of 1983 (NAD83). Vertical positions are referenced to the NAD83 ellipsoid and provided in meters. The National Geodetic Survey's (NGS) GEOID12A model is used to transform the vertical positions from ellipsoid to orthometric heights referenced to the North American Vertical Datum of 1988 (NAVD88). For data storage and Digital Coast provisioning purposes, the NOAA Coastal Services Center converted the data from orthometric heights referenced to the North American Vertical Datum of 1988 (NAVD88) to ellipsoid heights using the NGS GEOID12A model.