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An Airborne Scanning Laser Altimetry Survey of Long Valley, CaliforniaBetween 28 September and 7 October 1995, we conducted an airborne laser altimetry experiment over the Long Valley caldera, California, in which each of two scanning laser altimeters (dubbed SLICER and RASCAL) were flown in a NASA T-39 jet aircraft. Operating concurrently were a Global Positioning System (GPS) guidance system and dual frequency receivers for precise navigation and post-flight calculation or the airplane trajectory relative to a ground station, and an inertial navigation system (INS) for attitude determination. Reduction of raw laser ranges requires merging the differential kinematic GPS aircraft trajectory and the INS data with the laser data, and determination of the atmospheric delay. Data geolocation consists of obtaining the centre location and the mean elevation within each footprint in a geodetic coordinate system. The elevation of Crowley Lake is recovered to an accuracy of approximately 3 cm or better from 3 km above ground level and crossover analysis indicates that the elevation estimates are consistent from pass to pass. We test our geolocation procedures by comparing laser-derived elevations with those determined in situ for recognizable ground features. A comparison of laser and GPS-derived positions shows that the horizontal accuracy is better than the diameter of the footprint and vertical accuracy is within the error inherent in the range measurement. A comparison of SLICER elevation data with digital elevation models (DEMs) of the region shows that the DEM data provides surface topography to within stated accuracy limits. Although research continues to utilize the full potential of laser altimetry data, our results constitute a successful demonstration that the technique may be used to perform geodetic monitoring of surface topographic changes.
Document ID
20000075712
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Hofton, M. A.
(Scripps Institution of Oceanography La Jolla, CA United States)
Blair, J. B.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Minster, J.-B.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Ridgway, J. R.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Williams, N. P.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Bufton, J. L.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Rabine, D. L.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1999
Publication Information
Publication: International Journal of Remote Sensing
Publisher: Taylor and Francis Ltd.
Volume: 20
Issue: 0
ISSN: 0143-1161
Subject Category
Earth Resources And Remote Sensing
Funding Number(s)
CONTRACT_GRANT: NAS5-33019
CONTRACT_GRANT: NAG5-3001
Distribution Limits
Public
Copyright
Other

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