Research On Evaluation Method Of Spatial Disturbing Gravity By Combining Terrestrial And Airborne Gravity Data

This paper mainly studied the downward continuation of airborne gravity data and the evaluation method of Spatial disturbing gravity and described the current development of airborne gravity measurement technology as well as the basic theory.The paper focused on the way to determining the external disturbance of gravitational field by using Green's theorem.Then,I summarized the main work and innovation points as follows:1?The paper discussed the current development of airborne gravity measurement technology at home and abroad,the research status of downward continuation by using airborne gravity data,present research situation of approach to spatial disturbance gravity assignment,and introduced the basic theory of airborne gravity measurement.2?This paper studied several methods of downward continuation by using airborne gravity data,comparing and analyzing the inverse poisson integral iteration method,points mass theory and the regularization method.3?This paper studied the several kinds of upward continuation by using the gravity field elements,and brought in the template method of polar coordinates,which improved the poisson integral method,then compared and analyzed type-definition method,transformation method,the polar coordinates method and the improved method.4?In no gravity data distributing area,this paper studied using less terrestrial gravity data to control airborne gravity data,merging terrestrial gravity data and airborne gravity data with weighted mean method.The numerical computations indicate that this method is effective.5?Applying Green's theorem and taking grid numerical terrain surface as the boundary surface,ignoring the small disturbance on the vertical area of gravity horizontal component integration as well,we derived the formula to get the gravity field elements with vertical component of disturbance gravity(or gravity anomalies)and height anomalies directly,the results changed the classic solution to Molodenky problem,which needs continuation of ground data and presenting in a form of series solution.6?For the need of high precision of height anomaly near the points which are to be calculated,we deduced the formula to get the gravity field elements with vertical component of disturbance gravity(or gravity anomalies)and height anomaly difference.Experiments turned out precision of calculation could be improved by using height anomaly difference instead of height anomaly itself.7?After the Green's theorem and Stokes formula were used to calculate the external disturbance gravity three-component respectively in the ellipsoid results showed that the Green's theorem could get the equal precision to Stokes formula,but the kernel function is simple and easy to calculate.In the actual terrain surface the test results showed that the Green's theorem could get better precision to Stokes formula.