|2009 USGS/NPS Experimental Advanced Airborne Research Lidar (EAARL): Cape Hatteras
National Seashore - Post-Nor'easter Ida
||This is a bare-earth data lidar data set that was collected on November 27, 29 and
December 1, 2009 along the shoreline of the Cape Hatteras National Seashore in Dare
and Hyde Counties in North Carolina, after Nor'easter Ida. Binary point-cloud data
were produced from remotely sensed, geographically referenced elevation measurements
cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS).
Elevation measurements were collected over the area using the Experimental Advanced
Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an
aircraft to measure ground elevation, vegetation canopy, and coastal topography. The
system uses high-frequency laser beams directed at the Earth's surface through an
opening in the bottom of the aircraft's fuselage. The laser system records the time
difference between emission of the laser beam and the reception of the reflected laser
signal in the aircraft. The plane travels over the target area at approximately 50
meters per second at an elevation of approximately 300 meters, resulting in a laser
swath of approximately 240 meters with an average point spacing of 2-3 meters. The
EAARL, developed originally by NASA at Wallops Flight Facility in Virginia, measures
ground elevation with a vertical resolution of 15 centimeters. A sampling rate of
3 kilohertz or higher, results in an extremely dense spatial elevation dataset. Over
100 kilometers of coastline can be easily surveyed within a 3- to 4-hour mission.
When subsequent elevation maps for an area are analyzed, they provide a useful tool
to make management decisions regarding land development.