HR: 16:30h
AN: G54A-03    [Abstracts]
TI: Multi-beam Lidar Instrument Design, Measurement Capabilities, and Technical Readiness
AU: * Blair, B
EM: Bryan.Blair@nasa.gov
AF: NASA/GSFC, Laser Remote Sensing Laboratory Code 694, Greenbelt, MD 20771, United States
AU: Ranson, J
EM: Jon.Ranson@nasa.gov
AF: NASA/GSFC, Code 614.4, Greenbelt, MD 20771, United States
AU: Dubayah, R
EM: dubayah@geog.umd.edu
AF: University of Maryland, Department of Geography 2181 LeFrak, College Park, MD 20742, United States
AU: Coyle, B
EM: Barry.Coyle@nasa.gov
AF: NASA/GSFC, Code 554, Greenbelt, MD 20771, United States
AU: Salerno, C
EM: Cheryl.L.Salerno@nasa.gov
AF: NASA/GSFC, Code 556, Greenbelt, MD 20771, United States
AB: A multi-beam Laser Altimeter has been designed and studied at NASA Goddard Space Flight Center and the critical technologies have developed and tested resulting in a mature and technically ready instrument approach. The instrument consists of three separate beams each providing a near-contiguous profile of 25 m diameter laser footprints. The across-track separation of the beams can be <1 km to as much as ~5 km. A return waveform is collected for each footprint and the system has sufficient Signal-to-Noise Ratio (SNR) to penetrate dense (i.e. 98-99% cover) canopies in relatively clear sky conditions and can penetrate clouds to provide precise topography over unvegetated surfaces. The Multi-beam Laser Altimeter design includes a high-quality GPS receiver for providing precise orbital position information and a state-of-the-art Star Tracker and Inertial Measurement Unit to provide precise and accurate laser beam pointing knowledge. The digitizer-based ranging system will provide ranging to bare surfaces with ~3 cm range precision. The return waveforms will also provide vegetation height measurements with ~1 m of accuracy. The laser transmitters have been fully developed, characterize, and tested. Engineering Test Unit has been built at NASA/GSFC for environmental testing. Test units of the laser demonstrated 5 Billion shots without damage and diode testing indicates lifetimes of ~10 Billion shots per laser can be expected. A new waveform digitizer has been developed with improvements in sampling rate and dynamic range over the ICESat digitizer system, thus allowing higher quality waveforms to be collected, which is critical importantly for vegetation studies. This multi-beam Lidar design is the basis for the Lidar on the DESDynI (Deformation, Ecosystem Structure, and Dynamics of Ice) mission described in the NRC Decadal Survey Report that consists of a Multi-beam Lidar and an L-band InSAR to be launched in the 2010-2013 timeframe.
DE: 0452 Instruments and techniques
DE: 0794 Instruments and techniques
DE: 1694 Instruments and techniques
SC: Geodesy [G]
MN: 2007 Fall Meeting