Downward Continuation of the Free-Air Gravity Anomalies to the Ellipsoid Using the Gradient Solution, Poisson's Integral and Terrain Correction- Numerical Comparison and Computations
Abstract
The formulas for the determination of the coefficients of the spherical harmonic expansion of the disturbing potential of the earth are defined for data given on a sphere. In order to determine the spherical harmonic coefficients, the gravity anomalies have to be analytically downward continued from the earth's surface to a sphere - at least to the ellipsoid. The goal of this work is to continue the gravity anomalies from the earth's surface downward to the ellipsoid using recent elevation models. The basic method for the downward continuation is the gradient solution (the g1 term). The terrain correction has also been computed because of the role it can play as a correction term when calculating harmonic coefficients from surface gravity data. Because there is no global, dense gravity anomaly data, 5' x 5' mean elevation data has been used for the computations of the g1 term and the terrain correction on a global basis. The fast Fourier transformation has been applied to the computations.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1988
- Accession Number
- ADA203739
Entities
People
- Yan M. Wang
Organizations
- Ohio State University