Four-direction monopole directional antenna system and method for borehole radar detection

Abstract

The invention provides a four-direction monopole directional antenna system and method for borehole radar detection. The system comprises a borehole radar directional antenna system, a sequential feeding device, an in-borehole walking device, and a cable transmission device, wherein the borehole radar directional antenna system comprises a four-direction directional transmitting monopole antenna group, an omnidirectional receiving antenna and a sleeve, the four-direction directional transmitting monopole antenna group is used for sequentially and directionally radiating electromagnetic waves to each direction, the omnidirectional receiving antenna is used for receiving reflected waves, and the four-direction directional transmitting monopole antenna group and the omnidirectional receiving antenna are arranged in the sleeve; the sequential feeding device is used for sequentially controlling the drilling radar directional antenna system so as to sequentially and directionally radiate electromagnetic waves in different directions at the same depth, and detection without rotation is realized; the in-borehole walking device is arranged on the outer side of the sleeve and drives the whole drilling radar directional antenna system to move in a drilled hole; and the cable transmission device is used for transmitting a detection result of the drilling radar directional antenna system to a processor arranged on the ground and the sequential feeding device. Multi-directional orientation can be achieved without rotation, the diameter size is smaller than the engineering drilling size, the orientation performance is stable, and mutual coupling is avoided.

Description

technical field [0001] The invention belongs to the technical field of borehole radar detection, and in particular relates to a four-direction monopole directional antenna system and method for borehole radar detection. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] The borehole radar method is a broad-spectrum electromagnetic technique for determining the distribution of subsurface media. According to the different resistivity of the underground medium to be detected, the borehole radar detection method is currently divided into single-hole reflection measurement, cross-hole measurement and in-hole-surface measurement. When performing single-hole measurement, the transmitting antenna of the radar emits high-frequency broadband electromagnetic waves, and the receiving antenna receives the reflected waves from the geological body. and ot...

AI Technical Summary

Problems solved by technology

If the number of antennas and reflectors are superimposed in the radial direction of the cylindrical borehole and radiate in different directions, it can be used for directional detection without rotation, but the design of multi-antenna superposition will make the antenna size too large to penetrate Drilling, and the multi-antenna structure in the radial direction is prone to mutual coupling, which affects the directional performance

If the traditional half-wave dipole antenna with a reflector is used to superimpose the number of antennas and reflectors in the axial direction of the borehole, multi-directional orientation without rotation can also be achieved. It is very inconvenient, and the length is too long to complete the sequential feeding of the antenna, so that it is impossible to quickly perform traversal scanning detection

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