|2010 US Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Technical
Center of eXpertise (JALBTCX) Lidar: Northeast (Topo)
||These files contain topographic lidar data in LAS 1.2 format classified as ground
(2) and unclassified (1) in accordance with the American Society for Photogrammetry
and Remote Sensing (ASPRS) classification standards. Rejected or invalid data is classified
as noise (7). These data were collected by a HawkEye II (HEII) lidar sensor. The HEII
integrates topographic and bathymetric lidar sensors, and a digital camera on a single
remote sensing platform for use in coastal mapping and charting activities. Data coverage
generally extends along the MA coastline, from the waterline onshore 500 meters. Native
lidar data is not generally in a format accessible to most Geographical Information
Systems (GIS). Specialized in-house and commercial software packages are used to process
the native lidar data into 3D 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 acquired to the NAD83 ellipsoid. The National Geodetic Survey's
(NGS) GEOID09 model was used to transform the vertical positions from ellipsoid to
orthometric heights referenced to the North American Vertical Datum of 1988 (NAVD88).
The 3D position data are sub-divided into a series of files each covering approximately
5 kilometers of shoreline.