HR: 1340h
AN: G33B-1237    [Abstracts]
TI: Improving spatial and spectral estimates of terrestrial mass variations from GRACE data (while unlocking the secrets of the universe)
AU: * Simons, F J
EM: fjsimons@gmail.com
AF: Princeton University, Department of Geosciences, Princeton, NJ 08544, United States
AU: Dahlen, F
EM: fad@princeton.edu
AF: Princeton University, Department of Geosciences, Princeton, NJ 08544, United States
AU: Han, S
EM: schan@puuoo.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Planetary Geodynamics Laboratory, Greenbelt, MD 20771, United States
AU: Wiezorek, M A
EM: wieczor@ipgp.jussieu.fr
AF: Institut de Physique du Globe, Equipe d'Etudes Spatiales et Planetologie, St. Maur, 94107, France
AB: Geodesy and cosmology may be unlikely bedfellows, in this presentation we discuss the theoretical and practical advances that we have been making in adressing two problems common to both disciplines --- with examples. The first concerns the accurate (low bias, low variance) determination of mass variations from incomplete and noisy gravity data taken at satellite altitude, as is relevant to determine glacier mass fluxes. The second involves the estimation of the power spectrum of such fields from similar data. The first problem requires an estimate that is linear in the data, the second is quadratic. In both cases we take advantage of recently developed spherical localizing "Slepian" basis functions. For the first problem, our competition is from the algorithm developed by Swenson and Wahr, for the second we require comparisons with the maximum-likelihood method of spectral estimation currently in vogue in the cosmological community. We provide an intuitive and graphical discussion of the philosophy underlying the various methods, and illustrate our newest theoretical developements by showing them applied to data obtained as level-2 products from GRACE (with a special application to detecting the Sumatra-Andaman earthquake from space), as well as to the determination of the cosmic microwave-background spectrum (obtained using data from the WMAP satellite).
UR: http://www.frederik.net
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1241 Satellite geodesy: technical issues (6994, 7969)
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2007 Fall Meeting