HR: 1340h
AN: C23A-0943    [Abstracts]
TI: Assessment of ICESat Repeat Track Estimation Techniques for Polar Elevation Change Detection
AU: * Harpold, R E
EM: harpold@csr.utexas.edu
AF: Center for Space Research, 3925 West Braker Lane, Suite 200, Austin, Tx 78731, United States
AU: Urban, T J
EM: urban@csr.utexas.edu
AF: Center for Space Research, 3925 West Braker Lane, Suite 200, Austin, Tx 78731, United States
AU: Webb, C E
EM: webb@csr.utexas.edu
AF: Center for Space Research, 3925 West Braker Lane, Suite 200, Austin, Tx 78731, United States
AU: Schutz, B E
EM: schutz@csr.utexas.edu
AF: Center for Space Research, 3925 West Braker Lane, Suite 200, Austin, Tx 78731, United States
AB: Crossover methods have been a standard for measuring polar elevation change, but they do not provide dense enough coverage for some applications. As repeat track methods use all of the available data from a given instrument, they provide denser coverage (by about an order of magnitude for ICESat), but include topographic slope errors due to cross-track spacing between tracks from different times. In this presentation we assess the accuracy of a least squares approach to repeat-track elevation change estimation where no data interpolation is required. ICESat elevation data over Antarctica and Greenland from ten laser acquisition periods spanning 2003- 2007 are employed. We present a survey of different parameter-set estimation methods, including a variety of multiple-parameter and weighting techniques. We assess the relative quality of these repeat track results by comparing to crossover results and to ICESat elevation profiles during the same time periods. Relative impacts on different spatial scales are examined, from ice stream, to ice sheet, to continental-scale areas, including an estimation error assessment for equivalent water gain/loss.
DE: 0762 Mass balance (1218, 1223)
SC: Cryosphere [C]
MN: 2007 Fall Meeting