Knowledge Bank

This report compares the existing methods for solving the geodetic boundary value problem, i.e., the gravimetric determination of the geoid (traditional methods) or the physical surface of the earth (modern methods). A unified treatment is attempted by deducing all these methods from one very general integral equation. Gravity reduction is discussed from the traditional and the modern point of view. The different kinds of free-air anomalies and free-air reductions, which are a controversial subject, are compared. Emphasis lies on the general aspects of the methods discussed.