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NASA EAARL Lidar Test at Wallops Flight Facility
EAARL will provide new capabilities to survey sandy beaches, coastal vegetation, shallow bathymetry, and nearshore benthic habitats. The design sensor combines a hyperspectral scanner with a lidar that can precisely record the full reflected laser pulse (Figure 3). In contrast, the NASA Airborne Topographic Mapper (ATM) lidar currently in use by the CMG Program measures only the range to the leading edge of the first laser reflection. Aircraft costs are reduced for EAARL relative to the ATM, due to its compact design, low power requirement, and the substitution of an array of GPS antennas in the place of an Inertia Navigation System. All of these innovations minimize the airborne payload, and enable the use of light aircraft that are commonly available at low cost. EAARL also has the capability to sense the vertical complexity of the surface target "on the fly" during a given survey. This greatly reduces data volume over bare terrain, while simultaneously enabling the capture of detailed reflected pulse waveforms over forests and shallow water. The instrument's ability to adjust itself to the terrain on a pulse-by-pulse basis means that a single survey can provide a data set that is keyed to multiple applications. The possible uses for EAARL include coral community mapping, studies of changes along sandy coasts, the three-dimensional assessment of plant communities, and shallow bathymetric sounding. An equipment rack mounted over a port in the Cessna 310 recently passed the NASA engineering safety analysis, and the aircraft itself has passed the NASA safety review for flights over coastal waters. For the initial test flights this spring over Chincoteague Bay, Assateague Island, and coral reefs in Biscayne National Park, the survey crew will consist of a pilot and an instrument operator, and a vacant third seat will carry an observer. A future development goal for EAARL is to enable the pre-programming of flight waypoints and instrument operation. Following this upgrade, it may become possible to reduce the required onboard survey personnel to just a pilot.
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in this issue:
cover story: Institute for Science Instruction & Study Job Announcement: NOAA-USGS Benthic Habitat Post-Doc |