Line array multi-channel synchronous transient electromagnetic directional detection method and device thereof

Abstract

The invention discloses a line array multi-channel synchronous transient electromagnetic directional detection method and a device thereof. The method is characterized in that a transmitting line frame is arranged in the direction vertical to a detection direction and multiple channels of receiving line frames or magnetic bars are arranged forwards along the exploration direction, with the centerof the transmitting line frame as the starting point; a transient electromagnetic transmitter is started to transmit primary fields and multiple channels of synchronous acquisition systems synchronously acquire transient electromagnetic response secondary field signals according to the synchronous signals provided by the transient electromagnetic transmitter; the response signals of disturbing bodies around the transmitting line frame and behind coils and the mutual induction signals of a source coil and multiple channels of receiving coils are fast attenuated forwards and the abnormal response signals of front objects are gradually enhanced forwards; and directional explain for whether low-resistance abnormal bodies exist in front can be carried out according to the amplitudes and changecharacteristics of the signals which are regularly enhanced forwards. The method and the device are suitable for use in the fields such as advanced prediction in tunnels by the transient electromagnetic method and directional detection combining drill holes and the ground or airborne and ocean exploration by the transient electromagnetic method.

Description

technical field [0001] The invention relates to a line array multi-channel synchronous transient electromagnetic directional detection technology and an implementation method. It is suitable for advanced forecasting in tunnels or boreholes, it is also suitable for the combination of ground and borehole TEM exploration, and it is also suitable for water and air TEM exploration. technical background [0002] Transient electromagnetic method is a commonly used geophysical prospecting method. During implementation, the transmitter emits an electromagnetic field through the transmitting wire frame. When the primary field is turned off or at a certain time before it is used as a reference, a synchronization signal is sent to the receiving instrument. The coil or magnetic rod collects the electromagnetic induction signal of the surrounding medium under primary field excitation; usually the change value of the vertical component of the magnetic field is measured, using the formula d...

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Problems solved by technology

First, due to the strong mutual inductance signal between the transmitting wire frame and the receiving wire frame, it is difficult to identify or suppress this signal superimposed on the effective signal; second, due to changes in the observation time and excitation environment, the multiple observation signals that are transmitted and received The comparison between each other is not strong, which affects the resolution and interpretation of abnormalities; the third is that the signals received by the receiving coil come from all directions, and the transmitting and receiving coils on one receiving plane cannot identify which direction the abnormal signal comes from. Especially prominent when applied in

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