HR: 0830h
AN: G11A-0237    [PDF]
TI: Extracting High Resolution Information From Laser Altimetry Data by Analysing the Instrumental Error Budget
AU: * Davenport, I J
EM: ijd@mail.nerc-essc.ac.uk
AF: NERC Environmental Systems Science Centre, University of Reading Harry Pitt Bldg, Reading, Ber RG6 6AL United Kingdom
AU: Holden, N
EM: nick.holden@environment-agency.gov.uk
AF: UK Environment Agency National Centre for Environmental Data and Surveillance, Lower Bristol Road, Bath, BA2 9ES United Kingdom
AU: Gurney, R J
EM: rjg@mail.nerc-essc.ac.uk
AF: NERC Environmental Systems Science Centre, University of Reading Harry Pitt Bldg, Reading, Ber RG6 6AL United Kingdom
AB: The errors in airborne laser altimetry data are poorly understood, and inadequately quantified. While numbers such as 20cm elevation, 40cm planimetric error are generally cited, and this may well be adequate for large scale measurements, the error budget contributions for the different elements making up the laser altimetry system mean that the relative error between locally measured points is considerably lower. As an indication of the increase in information that can be extracted from such data with knowledge of the error budget, we recently demonstrated a processing algorithm which, with a standard altimetry acquisition of a farm field, was able to distinguish between a soil surface ploughed to 5cm in elevation roughness and a rolled soil surface, with a 92.5% success rate. Local relative measurements are better correlated because they are not subject to the instrumental disturbance that occurs between swathes, and the drifts due to the differential GPS and inertial navigation systems used to locate the aerial platform. To use such measurements effectively requires an understanding of the error sources affecting laser altimetry measurements. We present here a study of the error budget of an airborne laser altimetry system and describe the improvements in interpreting measurements that can be made by understanding the error budget. These enable us to extend the utility of airborne laser altimetry systems to the measurement of land surface properties, such as soil surface roughness and vertical vegetation density profiles, with a higher vertical resolution and better spatial coverage than is otherwise possible.
DE: 0933 Remote sensing
DE: 1294 Instruments and techniques
DE: 1824 Geomorphology (1625)
DE: 1894 Instruments and techniques
DE: 9805 Instruments useful in three or more fields
SC: Geodesy [G]
MN: 2003 Fall Meeting