A Study of the Aliasing Effect in Gravitational Potential Coefficients as Determined from Gravity Data

摘要

The computation of potential coefficients from gravity anomalies has been investigated from two points of view. The first area of investigation concerned the computation of anomalies from a defined set of potential coefficients using evaluations through an integrated procedure and though evaluation at the center of blocks on the surface of the sphere. These anomalies were then substituted into standard summation formulas to test the recovery of the original coefficients. It was found that the original coefficients were recovered better when a center point evaluation was made as opposed to the integrated approach. The second area of study concerned the aliasing effect caused by having gravity data of unequal standard errors in a weighted least squares adjustment. It was found that the aliasing effect alters all potential coefficients of a least squares solution. Using the coefficients found from solutions affected by the aliasing effect, it was also found that the higher degree anomaly information was not absorbed in the lower degree terms. (Author)