The Use of Gravity Anomalies on a Bounding Sphere to Improve Potential Coefficient Determinations.
Abstract
The precise determination of potential coefficients from terrestrial gravity data requires that, among other things, the topography of the earth's surface must be considered. This paper first formulates a procedure where the potential coefficients can be determined using anomalies determined on a sphere that encloses the mass of the earth. The resultant equations can also be formulated to compute correction terms to potential coefficients derived from uncorrected surface free-air anomalies. From degree 5 to degree 20, the improved set showed slightly better agreement with the GEM 9 (satellite derived) potential coefficients than the original coefficients. The correction of the original coefficients was small, however, being 1.8% of the original coefficients at degree 2, rising to 7.5% at degree 40. The anomaly correction terms were used to obtain an improved comparison of satellite derived 5 deg anomalies and terrestrial data. This was done by using the satellite determined potential coefficients to derive anomalies on a bounding sphere which were then downward continued to the surface. These anomalies showed a better agreement with the observed anomalies than did anomalies computed directly on the surface (mean square difference: 109 mgal squared vs. 91 mgal squared).
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1977
- Accession Number
- ADA045109
Entities
People
- Richard H. Rapp
Organizations
- Ohio State University