An Investigation of Methods for Estimating Gravity Anomalies and Their Application to Height Difference Determination

摘要

The horizontal gradients (of the vertical component) of gravity are accurately and efficiently measured in the field using gravimeter measurements and differential leveling. The measured horizontal gradients are used in conjunction with points of known anomaly to develop an analytical equation representing the anomaly profile or field. The osculating mode of multiquadric equations of topography and other irregular surfaces is applied using points of known anomaly and horizontal gradient to provide more accurate predictions of the anomaly field. The horizontal gradients are also used with measured gravity and an assumed vertical gravity gradient to determine gravimetric height differences. Height differences are also determined by utilizing the anomaly predictions and the correlation of anomaly with height in the free air gravity anomaly formula. Gravimetric heighting is found to produce the same size errors common to barometric leveling. (Author)