REALIZATION OF MONITORING AND MANAGEMENT METHOD FOR EXTREMELY LOW FREQUENCY ELECTROMAGNETIC OBSERVATION IN HUAILAI
CHI Hai-jiang;WEN Jia;Huailai Seismic Station;
The extremely low frequency(ELF)ground exploration project is one of the major national science and technology infrastructure construction projects approved by the National Development and Reform Commission in the Eleventh Five-year Plan. It uses the new artificial source extremely low frequency electromagnetic technology(CSELF)to carry out resource exploration, earthquake prediction and other cutting-edge scientific research. After several years of active preparation, 30 extremely low frequency seismic electromagnetic monitoring stations have been preliminarily built in the capital circle and the north-south seismic belt in Sichuan-Yunnan region to jointly record MT data from natural field sources and CSMT data from artificial sources. The latest generation of ADU-07 e magnetotelluric observation system produced by the company Metronix of Germany is selected for observation. Its output data format, transmission mode and analysis method are quite different from the precursory instruments commonly used in seismic stations in the Tenth Five-year Plan. This paper analyzes the problems that have occurred since the installation of the instrument at Huailai seismic station. According to the actual situation and experience, practical software is developed, which has significantly improved the observation method.The main problems include: 1)The observers cannot grasp the operation status of the instrument in time; 2)The amount of data generated by observation is large and there are a large number of files; 3)The instrument and server are highly secure and professional, which is difficult for station personnel to master; 4)Log filling and submission are cumbersome and error prone.The development of practical monitoring software, which can monitor the observation status and observation data in real time on site or remotely, has important practical value for the long-term opera tion and maintenance of the station. The software functions mainly include: quasi real-time inspection of the working conditions of observation instruments, fault alarm, inspection, transmission and genera tion of preprocessed EDI files in the server, automatic filling and submission of logs, etc. This paper introduces the parameter configuration, function application and application method of each module in detail.The paper introduces the key programming statements such as control, dynamic library, macro language command, reading meteorological instrument data and alarm service, which realize software functions by VB language.The practical application effect of the software in Huailai seismic station is introduced, and it is found that the observation data quality and operation effect of the station is improved and the expected design purpose is achieved with the software.Extremely low frequency observation is a transformation from magnetotelluric sounding to long-term continuous monitoring to meet the need for earthquake prediction. It is a transformation from short-term manned observation to long-term unattended observation, which is a test of instrument performance and maintenance. Using software, the complicated instrument inspection is changed into “one key” threshold judgment, which improves the anomaly processing ability and response speed of the instrument. The file naming, data supplementary transmission, preprocessing, log submission and other operations under Linux system are turned into shortcut buttons under windows, which are standardized and convenient, suitable for the working conditions and popularizing and application in the stations.