1. College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China;
2. Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China;
3. China Water Northeastern Investigation, Design & Research Co., Ltd, Changchun 130062, China

Edge detection plays an important role in geological interpretation of potential field data,which can indicate the subsurface faults,contact,and other tectonic features.A variety of methods have been proposed to detect and enhance the edges.3D structure tensor can well delineate the edges of geological bodies,however,it is sensitive to noise and additional false edges need to be removed artificially.In order to overcome these disadvantages,this paper redefines the 3D structure tensor with a Gaussian envelop and proposes a new normalized edge detector,which can remove the additional false edges and reduce the influence of noise effectively,and balance the edges of different amplitude anomalies completely.This method has been tested on the synthetic and measured gravity data,showing that the new improved method achievesbetter results and reveals more details.