Shandong Physical and Chemical Exploration Institute, Jinan 250013, China

According to the small subdomain filtering principle, the small subdomain filtering produces abnormal boundary distortion mainly as high frequency interference. A combination of a small subdomain filtering and non-local mean filtering method is proposed to overcome the abnormal boundary distortion problem in small subdomain filtering. The good boundary enhancement ability of small sub-domain filtering and the high-frequency detail protection ability of non-local mean filtering are used to suppress the small sub-domain filtering defect while protecting the boundary enhancement effect of the small sub-domain filtering as much as possible. The simulation calculation and the measured gravity data processing in the Laizhou Bay area show that the proposed method suppresses the boundary distortion effect generated by the small sub-domain filtering while enhancing the anomaly boundary, and obtains better gravity anomaly processing result. Compared with single small domain filtering, the proposed method does not need to consider the abnormal boundary shape, and is more stable and universal.