Development Of Tunel-Borehole-surface EM Receiver

Borehole-tunnel-surface electromagnetic method with the existing tunnel,borehole and mining area,will launch the source on the surface,wells,tunnel,making receiver close to or through the mineral body,but also realize the differ axis source transmission,high power transmission,abnormal value is more obvio?s;in acquiring the electrical resistivity based on simultaneo?s acquisition of polarizability the spectral parameters,IP parameters.Therefore,it is expected to play an important role in the process of "tapping the blind" in metal mines.Electromagnetic receiver is the electromagnetic field operation observation equipment,its performance directly affects the effectiveness of the method.This dissertation design through numerical simulation of borehole surface electromagnetic method main parameters of the receiver;according to the requirements of the project contract by relying on the technology and the modeling results of the hardware and software design of the receiver,including the surface-tunnel electromagnetic receiver,borehole EM receiver,current recorder;the innovative development of non-contacted electrode,small audio three axis induction sensor;and through a large number of indoor and field tests verify the technical specification of the receiver;included in the implementation of multi channel and distributed technology based on the conventional observation,made a series of key EM observation technology: low noise EM field observation technology,large dynamic range and high precision observation technology time synchronization technology,intelligent data acquisition technology,full waveform current recording technology,tunnel and borehole EM observation technology.This dissert mainly studied three aspects: 1)study on the electromagnetic method;2)developed the hardware and software of surface-tunnel electromagnetic receiver,current recorder,borehole EM receiver;3)indoor and field test.Main specifications of borehole-surface-tunnel receiver:Borehole-surface-tunnel EM acquisition;Channels: Surface:6(Ex/Ey/Ez/Hx/Hy/Hz),Borehole 4(Bx/By/Bz/Ez);Bandwidth: DC-10 k Hz;Noise floor: E: 10 n V/m/rt(Hz)@1Hz,H: 0.1p T/rt(Hz)@1Hz:Dynamic range: 117 d B@fs=2400Hz;Clockdrift error: less than 10?s/hr;Support method module: TDIP,SIP,CSAMT,AMT,MTIn order to meet a series of technical specification,mainly to overcome the full frequency range low noise and high dynamic and high precision phase,full waveform current records and other technical problems,and has made important progress in the non-contacted electrode,small three axis audio magnetic sensor,which is a beneficial try in the ease of ?se,portability,high efficiency etc..Indoor and field tests have verified the effectiveness and the advanced specification of the receiver.