Removing Grid Effect of 3-D Euler Deconvolution using Rotating Coordinate

Abstract

A new method for removing grid effect of Euler deconvolution is suggested. Gridding is inevitable process for calculating Euler deconvolution, but in the process of gridding and calculating derivative using FFT, errors are generated like Gibb\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'s phenomenon, edge effect, and circular convolution problem. Solutions which are locations and depths of anomaly bodies are calculated at all window locations, therefore, undesirable, scattered, and too many solutions are achieved and looks like meaningless. In this paper, rotating coordinate technique is used for removing grid effect of Euler deconvolution. Once Euler deconvolution is calculated for locations and depths of anomaly bodies at all window positions, the coordinate is rotated until 90 degree by 15 degree, and re-calculated for locations and depths. The process for removing grid effect is the follows: (1) Rotate the gridded potential data from 0 to 90 degree (2)Calculate the conventional 3-D Euler deconvolution for each data (3)Re-rotate Euler solution(locations and depths) to original coordinate (4) Collocation each solution and remove the solution which is not shown in others. Total 7 solutions can be achieved from these procedures, and common locations and depths results which are shown in all 5 solutions are accepted. The effectiveness of rotating technique is evaluated by using rectangular prism model which has 1km thickness at 5km depth from ground. Random noise also added for verifying the rotating technique. In case of adding noise, the depth accuracy become lower, but location still shows good estimate. This method is also implemented to analysis the tectonic interpretation of the Eastern Asia including Korea, China, and Japan using GRACE and CHAMP satellite gravity and magnetic data