The Research Of Downward Continuation Of Regularization Methods For Three-dimensional Gravitational Field Based On The Depth Change

The continuation of potential field can highlight the shallow anomaly, Inference fieldsource depth. We know that the upward continuation is ill-posed problem, a strict derivation inmathematics and it is conspicuous for the actual data processing effect.Gravity potential fielddownward continuation refers to start from the observation surface, to the field source directionof the extension, is a typical ill-posed problem. We all know the more closer to the source bodythe more better results, but high frequency interference during downward Continuation makesthe downward can’t continue, sometimes even coverage of useful information. So, it is importantto find a downward continuation method to suppress high-frequency interference in realproblem and realize more stable and accurate downward continuation.On the basis of previous studies, I introduce a method of downward continuation ofregularization methods for three-dimensional gravitational field based on the depthchange.Mainly discussed the regularized solution of ill-posed problem, the originalfiltering factor low-pass filter to bandpass filter,derive the computational formulas ofregularization parameter, and cut-off frequency f1,f2which was based on the depthchanges. In order to extend the boundary effect produced in the process of solution, thispaper joined the cosine expansion theory.And then, tested by simple density model,complicated density model and the model of various oil and gas reservoir, the paperproving validate the reliability, practicability of the method.At last, explore the distributionthrough the real gravity data of Miaodao Islands.