2006 LiDAR data for Colonial National Historical Park

Science Applications International Corporation (SAIC)

LIDAR in LEICA Imagine (.img) file format for COLO. Abstract: LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. Using a combination of laser rangefinding, GPS positioning and inertial measurement technologies; LIDAR instruments are able to make highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures and vegetation. This data was collected at a resolution of 1 meter and includes reflective surface, last return, bare earth model and intensity data in separate data files. Purpose: LIDAR data is used for 3D visualization, elevation based analysis and for feature extraction. Supplemental_Information: Reflective surface data represents the DEM created by laser energy reflected from the first surface encountered by the laser pulse. Some energy may continue beyond this initial surface to be reflected by a subsequent surface as represented by the Last Return data. Intensity information is captured from the Reflective Surface pulse and indicates the relative energy returned to the sensor as compared to the energy transmitted. The Intensity image is not calibrated or normalized but indicates differences in energy absorption due to the the interaction of the surface materials with laser energy at the wavelength transmitted by the sensor. Bare earth model is created by identifying those returns that fall on the ground surface and interpolating a surface between these points. In this manner buildings and vegetation are removed from Bare Earth Model. This data set does not include bridges and overpasses in the Bare Earth model as the delineation point for these structures is not reliably discernable in the LiDAR data.