|2004 USGS/NASA Experimental Advanced Airborne Research Lidar (EAARL): Northern Gulf
of Mexico, Post-Hurricane Ivan
||ASCII xyz point cloud data were produced from remotely-sensed, geographically-referenced
elevation measurements in cooperation with the U.S. Geological Survey (USGS) and National
Air and Space Administration (NASA). Elevation measurements were collected over the
area using the NASA 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. The EAARL, developed by NASA at Wallops Flight Facility in Virginia, measures
ground elevation with a vertical resolution of 15 centimeters. A sampling rate of
3 kHz or higher results in an extremely dense spatial elevation data set. Over 100
kilometers of coastline can be easily surveyed within a 3 to 4 hour mission time period.
When subsequent elevation maps for an area are analyzed, they provide a useful tool
to make management decisions regarding land development.