Data quality and spectrum analysis of geoelectric field at Wengtian station in Hainan

The observation object of the geoelectric field observation system is the geoelectric field intensity vector. Its purpose is to explore the change of the geoelectric field before earthquake, to obtain the electrical structure and its change law of underground and rock layer, and to develop the change characteristics of the geoelectric field in the process of seismogenesis by observing the intensity of geo electric field on the surface. The data of Wengtian geoelectric station since its establishment are sorted out in detail, and the quality of the data since its operation is analyzed by calculating the difference and correlation, the reasons for the good data quality are summarized, and some suggestions on how to improve the data quality in the next step are given. The curve of geoelectric field observation data at Wengtian station has an obvious daily variation form of one peak and one valley. The spectrum analysis shows that the dominant periods are 24, 12 and 6 hours, with 24 hours as the main period. By using the method of dominant azimuth angle, it is found that the dominant azimuth angle is narrowed and deflected from 2017 to 2018, and the anomaly is analyzed and discussed.