REGIONAL GRAVITY FIELD MODELLING

In this contribution two mathematical models for determination of the regional geoid from discrete observations of gravity on ground and at low-altitude aircraft are reviewed. Both cases are dealt with as completely independent, i.e. no data combination is considered herein. It is shown that the mathematical model for geoid determination from both ground and airborne gravity can rely on a single integral formula: in the case of ground data an inverse of the Fredholm integral equation of the first kind must numerically be solved while airborne data allow for a direct use of specifically developed Green's integral formula. Thus both models may be based on a single-step integration that has several favorable characteristics among which the most important are fast computer evaluation and efficient data utilization. Numerical attributes of the two models are tested using a set of high-frequency synthetic geopotential coefficients.