HR: 0800h
AN: G51C-0099    [Abstracts]
TI: Spherical Harmonic Representation of Very High Resolution Global Datasets
AU: * Blais, J
EM: blais@ucalgary.ca
AF: Dept. of Geomatics Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, AB T2N 1N4 Canada
AU: * Blais, J
EM: blais@ucalgary.ca
AF: Pacific Institute for the Mathematical Sciences, University of Calgary, 2500 University Dr. N.W., Calgary, AB T2N 1N4 Canada
AU: Soofi, M A
EM: soofi@ucalgary.ca
AF: Dept. of Geomatics Engineering, University of Calgary, 2500 University Dr. N.W., Calgary, AB T2N 1N4 Canada
AB: Spherical harmonics have traditionally been used to represent potential fields of the Earth such as gravity and magnetic fields. This allows a convenient way of storing information about the field in terms of spectral coefficients of the spherical harmonic transform and reproducing it using the inverse spherical harmonic transform. As more data are obtained, especially from satellites, the spectral coefficients can be recomputed to better define precision and resolution of the field. Recently, spherical harmonics have also been used to model topography and other observable properties of the Earth and other planets. The dense global datasets can be preserved properly by using very high degree and order spherical harmonics. This, however, presents two challenges. First, the numerical stability of computations and second, the computational efforts required. For kilometer scale resolution, this research has explored both challenges for analysis and synthesis, and proposes solutions using Chebychev quadrature and recent advances in 64-bit arithmetic as well as parallel and grid computations. The developed algorithms are computationally efficient and numerically stable for all kinds of applications.
DE: 3210 Modeling
DE: 3260 Inverse theory
DE: 1214 Geopotential theory and determination
DE: 0903 Computational methods, potential fields
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting