Optimal receiving system for earth electrode current field

Abstract

The present invention belongs to the field of communications technology and provides an optimal ground electrode current field reception system, comprising: a coarse detection module for roughly detecting the directionality of ground electric field signals and power frequency interference signals based on a designed orthogonal L-shaped electrode array; and a fine detection module for accurately measuring the directionality of ground electric field signals and power frequency interference signals based on a semicircular array structure composed of multiple L-shaped electrodes, and selecting an optimal receiving channel based on the principle of optimal signal-to-interference-noise ratio. By measuring the directionality of ground electric field signals and power frequency interference signals based on an orthogonal L-shaped electrode array and a semicircular array structure composed of multiple L-shaped electrodes, and selecting an optimal receiving channel based on the principle of optimal signal-to-interference-noise ratio, the present invention improves the reception performance of electrical signals in a through-the-ground communication environment and has greater anti-interference capabilities than traditional randomly arranged detection electrodes.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a ground electrode current field optimal receiving system. Background Art

[0002] In recent years, with the development of underground resources and the increasing demand for geological exploration, through-the-earth communication (TTE) has gradually attracted widespread attention as a breakthrough technology. Figure 1 As shown in the figure, the ground electrode current field through-the-ground communication system is one of them. By laying electrodes on the surface or underground and using extremely low-frequency electric fields to transmit information, it can achieve direct communication between the surface and the underground, or between the surface and the ground. This system is mainly used in mine communication, underground facility communication, and emergency rescue. Its core advantage lies in its extremely strong penetration, which can complete long-distance information transmission without relying on traditional wireless signals. However, because the through-the-ground communication system operates at very low frequency (VLF) or even lower frequency bands, it is susceptible to power frequency interference and other low-frequency noise, which greatly reduces the system's signal-to-noise ratio (SNR), thereby affecting the signal reception quality.

[0003] The interference signal of the existing through-the-ground communication system at the receiving end is mainly the power frequency interference signal, which mainly comes from the electromagnetic field of the power system, such as Figure 2 As shown in the figure, it has strong directionality and periodicity, and its frequency (such as 50Hz or 60Hz) is close to the operating frequency of the ground-through communication system. The notable characteristics of this interference signal are a stable sinusoidal waveform and a high amplitude, which makes the power frequency interference have a significant shielding effect on the signal receiving end, often obscuring or distorting the effective communication signal. In addition, the placement of the electrodes, the internal noise of the receiving equipment, and the complex electromagnetic conditions of the environment further increase the interference challenges at the receiving end. In this case, improving the signal-to-interference-noise ratio and reducing the shielding of the effective signal by the power frequency interference have become important issues facing the ground electrode current field ground-through communication technology.

[0004] Currently, researchers primarily use frequency-domain filtering to suppress power-frequency interference, such as narrowband filters and notch filters. These methods rely on analyzing the spectral characteristics of power-frequency interference and mitigating its impact through spectral isolation. However, frequency-domain filtering methods fail to effectively utilize the spatial characteristics of the signal, resulting in power-frequency interference still significantly affecting the desired signal in spatial directions.

[0005] Therefore, it is necessary to provide an optimal receiving system for the ground electrode current field. Summary of the Invention

[0006] The present invention provides an optimal ground electrode current field receiving system. This system uses an orthogonal L-shaped electrode array and a semicircular array structure composed of multiple L-shaped electrodes to measure the directionality of ground electric field signals and power frequency interference signals. Furthermore, the optimal receiving channel is selected based on the principle of optimal signal-to-interference-noise ratio. This improves the reception performance of electrical signals in through-the-ground communication environments and offers greater anti-interference capabilities than traditional randomly arranged detection electrodes.

[0007] The present invention provides a ground electrode current field optimal receiving system, comprising:

[0008] The coarse detection module is used to roughly detect the directionality of the earth's electric field signal and the power frequency interference signal based on the designed orthogonal L-shaped electrode array;

[0009] The precision inspection module is used to accurately measure the directionality of geoelectric field signals and power frequency interference signals based on a semicircular array structure composed of multiple L-shaped electrodes, and select the best receiving channel based on the principle of optimal signal-to-interference-noise ratio.

[0010] Furthermore, based on the designed orthogonal L-shaped electrode array, the directionality of the ground electric field signal and the power frequency interference signal is roughly detected, including:

[0011] An orthogonal L-shaped ground electrode array is formed based on three buried electrodes; the three buried electrodes include electrode 0, electrode 1 and electrode 2;

[0012] Based on the orthogonal L-shaped ground electrode array, a detection channel is formed; the detection channel includes channel 1 and channel 2; among them, electrode 0 and electrode 1 are connected to the detection device through a wire to form channel 1, and electrode 0 and electrode 2 are connected to the detection device through a wire to form channel 2; electrode 0 is connected to the positive electrode of channel 1 and the positive electrode of channel 2 respectively, electrode 1 is connected to the negative electrode of channel 1, and electrode 2 is connected to the negative electrode of channel 2;

[0013] Based on the initial phase difference and amplitude of the geoelectric field signal, as well as the initial phase difference and amplitude of the power frequency interference signal obtained by detecting the detection channel, the directionality of the geoelectric field signal and the power frequency interference signal is roughly detected.

[0014] Furthermore, an orthogonal L-shaped ground electrode array is formed based on the design of three buried electrodes, including: driving three metal electrodes into the ground at a certain distance, and detecting the geoelectric field signal in the ground through the metal electrodes.

[0015] Furthermore, the directionality of the ground electric field signal and the power frequency interference signal is roughly detected, including:

[0016] Detect the direction of the geoelectric field signal according to the detection channel;

[0017] Detect the direction of the power frequency interference signal according to the detection channel.

[0018] Furthermore, detecting the direction of the geoelectric field signal according to the detection channel includes:

[0019] After intercepting the geoelectric field signal at the same starting sampling points, the area where the geoelectric field line is located is determined by the initial phase relationship of the geoelectric field signal of the detection channel, and then the angle α between the direction of the geoelectric field line and the line connecting electrodes 0 and 1 is determined by the following formula: s , to obtain the direction of the geoelectric field signal;

[0020]

[0021] Wherein, E1 is the electric field strength from electrode 0 to electrode 1, and E2 is the electric field strength from electrode 0 to electrode 2.

[0022] Furthermore, detecting the direction of the power frequency interference signal according to the detection channel includes:

[0023] Use a bandpass filter to extract the 50Hz power frequency interference signal and obtain 10 seconds of power frequency interference signal data; calculate the angle θ between the power frequency interference signal direction and channel 1 using the following formula n (t);

[0024]

[0025] is the voltage amplitude of the power frequency interference signal received by channel 1 within t seconds, is the voltage amplitude of the power frequency interference signal received by channel 2 within t seconds; θ n (t) is the angle between the power frequency interference signal direction and channel 1 within t seconds.

[0026] Furthermore, based on a semicircular array structure composed of multiple L-shaped electrodes, the directionality of the geoelectric field signal and the power frequency interference signal is accurately measured, and the optimal receiving channel is selected based on the principle of optimal signal-to-interference-noise ratio, including:

[0027] Arrange ground electrode arrays in different directions at the receiving end to test and obtain the angles of the electric field lines at multiple receiving ends;

[0028] For multiple receiving-end electric field line angles, the truncated average method is used to first remove the maximum and minimum values, and then the average value of the remaining receiving-end electric field line angles is calculated to obtain the accurately measured receiving-end electric field line angle;

[0029] Based on the optimization problem of maximizing the signal-to-interference-noise ratio, the optimal receiving channel is calculated and obtained according to the angle between the electric field lines at the receiving end.

[0030] Furthermore, ground electrode arrays in different directions are arranged at the receiving end to test and obtain multiple angles of electric field lines at the receiving end, including:

[0031] First, a semicircular array ground electrode detection device is constructed using 2m buried electrodes, consisting of 2m-1 channels, or m orthogonal detection channels, that is, m L-shaped electrode groups; the distance between electrode No. 0 and the other electrodes is 1 meter;

[0032] Measure and calculate the angle α between the direction of the geoelectric field line of the i-th L-shaped electrode group and the line connecting channel 1 si , and the angle α between the ith power frequency interference signal and the line connecting channel 1 ni ;

[0033]

[0034] α si represents the deviation angle of the i-th geoelectric field signal relative to the direction of channel 1; α ni Indicates the deviation angle of the i-th power frequency interference signal relative to the direction of channel 1.

[0035] Furthermore, for multiple receiving end electric field line direction angles, the maximum and minimum values are first removed by using the truncated average method, and then the average value of the remaining receiving end electric field line direction angles is calculated to obtain the accurately measured receiving end electric field line direction angle, including:

[0036] The angle between the direction of m geoelectric field signals and the positive direction of the x-axis is δ s1 , δ s2 ,...,δ sm , the final average angle δ of the geoelectric field signal relative to the positive direction of the x-axis s for:

[0037]

[0038] The measured angle of m power frequency interference signals is δ n1 , δ n2 ,...,δ nm , the final average angle δ of the power frequency interference signal relative to the positive direction of the x-axis n for:

[0039]

[0040] Furthermore, based on the set optimization problem of maximizing the signal-to-interference-noise ratio, the optimal receiving channel is calculated and obtained according to the angle between the electric field lines at the receiving end;

[0041] Set up an optimization problem to maximize the signal-to-interference-noise ratio; the optimization problem is:

[0042]

[0043] The constraints are: s ∈[0, 180°], where δ e is the angle between the connection direction of the electrode of a single channel and the positive direction of the x-axis; the optimal electrode placement direction when the signal-to-interference-noise ratio reaches the maximum value is obtained according to the optimization problem. At this time, select Compare the two channels with the smallest angle and their corresponding f(δ e ) value, and select the larger one as the receiving channel; where,

[0044]

[0045] Compared with the existing technology, the present invention has the following advantages and beneficial effects: by measuring the directionality of the ground electric field signal and the power frequency interference signal based on the orthogonal L-shaped electrode array and the semicircular array structure composed of multiple L-shaped electrodes, and selecting the optimal receiving channel based on the principle of optimal signal-to-interference-noise ratio, the reception performance of the electric signal in the ground communication environment is improved, and the anti-interference ability is stronger than the traditional randomly arranged detection electrodes.

[0046] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0047] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0049] Figure 1 This is a schematic diagram of the principle of the ground electrode current field through-the-ground communication system;

[0050] Figure 2 This is a schematic diagram of the measured power frequency interference signal;

[0051] Figure 3 This is a schematic diagram of the structure of the optimal receiving system for the ground electrode current field;

[0052] Figure 4 Schematic diagram of an orthogonal L-shaped ground electrode array, with the electric field lines located in region 1;

[0053] Figure 5 Schematic diagram of the orthogonal L-shaped ground electrode array, with the electric field lines located in region 2;

[0054] Figure 6 It is a schematic diagram of a semicircular array ground electrode detection device;

[0055] Figure 7 Schematic diagram of the signal detected by the orthogonal L-shaped ground electrode array when the electric field line is located in region 1;

[0056] Figure 8 Schematic diagram of the signal detected by the orthogonal L-shaped ground electrode array when the electric field lines are located in region 2. DETAILED DESCRIPTION

[0057] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0058] The present invention provides an optimal receiving system for the ground electrode current field, such as Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, it includes: a coarse detection module, which is used to roughly detect the directionality of the ground electric field signal and the power frequency interference signal based on the designed orthogonal L-shaped electrode array;

[0059] The precision inspection module is used to accurately measure the directionality of geoelectric field signals and power frequency interference signals based on a semicircular array structure composed of multiple L-shaped electrodes, and select the best receiving channel based on the principle of optimal signal-to-interference-noise ratio.

[0060] The working principle of the above technical solution is as follows: in order to realize the optimal receiving system of the ground electrode current field, the present invention proposes a coarse detection module for roughly detecting the directionality of the ground electric field signal and the power frequency interference signal based on the designed orthogonal L-shaped electrode array; and proposes a fine detection module for accurately measuring the directionality of the ground electric field signal and the power frequency interference signal based on a semicircular array structure composed of multiple L-shaped electrodes, and selecting the optimal receiving channel based on the principle of optimal signal-to-interference-noise ratio.

[0061] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, the directionality of the ground electric field signal and the power frequency interference signal is measured based on the semicircular array structure composed of an orthogonal L-shaped electrode array and multiple L-shaped electrodes, and the optimal receiving channel is selected in combination with the principle of optimal signal-to-interference-noise ratio, thereby improving the reception performance of the electrical signal in the ground communication environment and having a stronger anti-interference ability than the traditional randomly arranged detection electrodes.

[0062] In one embodiment, based on a designed orthogonal L-shaped electrode array, the directionality of the ground electric field signal and the power frequency interference signal is roughly detected, including:

[0063] An orthogonal L-shaped ground electrode array is formed based on three buried electrodes; the three buried electrodes include electrode 0, electrode 1 and electrode 2;

[0064] Based on the orthogonal L-shaped ground electrode array, a detection channel is formed; the detection channel includes channel 1 and channel 2; among them, electrode 0 and electrode 1 are connected to the detection device through a wire to form channel 1, and electrode 0 and electrode 2 are connected to the detection device through a wire to form channel 2; electrode 0 is connected to the positive electrode of channel 1 and the positive electrode of channel 2 respectively, electrode 1 is connected to the negative electrode of channel 1, and electrode 2 is connected to the negative electrode of channel 2;

[0065] Based on the initial phase difference and amplitude of the geoelectric field signal, as well as the initial phase difference and amplitude of the power frequency interference signal obtained by detecting the detection channel, the directionality of the geoelectric field signal and the power frequency interference signal is roughly detected.

[0066] The working principle of the above technical solution is: in order to realize the orthogonal L-shaped electrode array based on the design and roughly detect the directionality of the ground electric field signal and the power frequency interference signal, the present invention first designs an orthogonal L-shaped ground electrode array based on three buried electrodes; the detection channel includes channel 1 and channel 2; wherein, electrode No. 0 is connected to electrode No. 1 through a wire and then connected to the detection equipment to form channel 1, and electrode No. 0 is connected to electrode No. 2 through a wire and then connected to the detection equipment to form channel 2; electrode No. 0 is respectively connected to the positive pole of channel 1 and the positive pole of channel 2, electrode No. 1 is connected to the negative pole of channel 1, and electrode No. 2 is connected to the negative pole of channel 2; finally, according to the initial phase of the ground electric field signal obtained by detecting the detection channel The directionality of the geoelectric signal and the power-frequency interference signal can be roughly detected by measuring the initial phase difference of the geoelectric signal detected by the two detection channels and the amplitude of the geoelectric field signal, as well as the initial phase difference of the power-frequency interference signal and the amplitude of the power-frequency interference signal. The initial phase difference of the geoelectric signal detected by the two detection channels can be used to determine the area in which the electric field line of the geoelectric signal is located. The inverse tangent calculation of the geoelectric signal amplitude detected by the two channels can then be performed to determine the angle to roughly find the direction of the geoelectric signal. Similarly, the initial phase difference of the power-frequency interference signal detected by the two detection channels can also be used to determine the area in which the power-frequency interference signal is located. The inverse tangent calculation of the power-frequency interference signal amplitude detected by the two channels can then be performed to determine the angle to roughly find the direction of the power-frequency interference signal.

[0067] The beneficial effect of the above technical solution is: by adopting the solution provided in this embodiment, an orthogonal L-shaped ground electrode array is formed by designing three buried electrodes, providing conditions for rough detection of the directionality of electric field signals and power frequency interference signals.

[0068] In one embodiment, Figure 4 and Figure 5As shown, an orthogonal L-shaped ground electrode array is formed based on three buried electrodes, including: driving three metal electrodes into the ground at a certain distance, and detecting the ground current field signal in the ground through the metal electrodes.

[0069] The working principle of the above technical solution is: in order to realize the orthogonal L-shaped ground electrode array composed of three buried electrodes, the present invention drives three metal electrodes into the ground at a certain distance, and detects the ground current field signal in the ground through the metal electrodes.

[0070] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, three buried electrodes are designed to form an orthogonal L-shaped ground electrode array, providing conditions for the formation of a current field.

[0071] In one embodiment, roughly detecting the directionality of the earth electric field signal and the power frequency interference signal includes:

[0072] Detect the direction of the geoelectric field signal according to the detection channel;

[0073] Detect the direction of the power frequency interference signal according to the detection channel.

[0074] The working principle of the above technical solution is: in order to roughly detect the directionality of the geoelectric field signal and the power frequency interference signal according to the detection channel, the present invention first detects the direction of the geoelectric field signal according to the detection channel; and then detects the direction of the power frequency interference signal according to the detection channel.

[0075] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, by detecting the direction of the geoelectric field signal and the direction of the power frequency interference signal according to the detection channel, the directionality of the geoelectric field signal and the power frequency interference signal can be ensured.

[0076] In one embodiment, detecting the direction of the geoelectric field signal according to the detection channel includes:

[0077] After intercepting the geoelectric field signal at the same starting sampling points, the area where the geoelectric field line is located is determined by the initial phase relationship of the geoelectric field signal of the detection channel. When the detected two channel signals are as follows Figure 7 When the initial phases are the same as shown, the geoelectric field lines are located at Figure 4 When the initial phases of the two channel signals detected are opposite as shown in Figure 8, that is, they differ by 180°, the geoelectric field lines are located at Figure 5 The angle α between the direction of the earth's electric field line and the line connecting electrodes 0 and 1 is determined by the following formula. s , to obtain the direction of the geoelectric field signal;

[0078]

[0079] Wherein, E1 is the electric field strength from electrode 0 to electrode 1, and E2 is the electric field strength from electrode 0 to electrode 2.

[0080] The working principle of the above technical solution is as follows: In order to detect the direction of the earth electric field signal according to the detection channel, the present invention first intercepts the earth electric field signal at the same starting sampling point number, and then determines the area where the electric field line is located by detecting the initial phase relationship of the two channel signals. Then, the angle α between the direction of the earth electric field line and the line connecting electrodes 0 and 1 is determined by the following formula: s , to obtain the direction of the geoelectric field signal;

[0081]

[0082] Wherein, E1 is the electric field strength from electrode 0 to electrode 1, and E2 is the electric field strength from electrode 0 to electrode 2.

[0083] The beneficial effect of the above technical solution is that: by adopting the solution provided by this embodiment, the direction angle of the geoelectric field signal can be obtained by detecting the direction of the geoelectric field signal according to the detection channel.

[0084] In one embodiment, detecting the direction of the power frequency interference signal according to the detection channel includes:

[0085] Use a bandpass filter to extract the 50Hz power frequency interference signal and obtain the data of the first 10 seconds of the power frequency interference signal; calculate the angle θ between the direction with the maximum intensity of the power frequency interference signal and channel 1 using the following formula n (t);

[0086]

[0087] is the voltage amplitude of the power frequency interference signal received by channel 1 within t seconds, is the voltage amplitude of the power frequency interference signal received by channel 2 within t seconds; θ n (t) is the angle between the direction of maximum power frequency interference signal intensity and channel 1 at time t seconds.

[0088] The working principle of the above technical solution is as follows: in order to detect the direction of the power frequency interference signal according to the detection channel, the present invention first uses a bandpass filter to extract the 50Hz power frequency interference signal and obtains the data of the first 10 seconds of the power frequency interference signal; then calculates the angle θ between the direction with the maximum intensity of the power frequency interference signal and channel 1 by the following formula n (t);

[0089]

[0090] is the voltage amplitude of the power frequency interference signal received by channel 1 within t seconds, is the voltage amplitude of the power frequency interference signal received by channel 2 within t seconds; θ n (t) is the angle between the direction of maximum power frequency interference signal intensity and channel 1 at time t seconds.

[0091] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, the direction of the power frequency interference signal can be detected by calculating the angle between the direction with the maximum intensity of the power frequency interference signal and channel 1.

[0092] In one embodiment, based on a semicircular array structure composed of multiple L-shaped electrodes, the directionality of the geoelectric field signal and the power frequency interference signal is accurately measured, and the optimal receiving channel is selected based on the principle of optimal signal-to-interference-noise ratio, including:

[0093] Arrange ground electrode arrays in different directions at the receiving end to test and obtain the angles of the electric field lines at multiple receiving ends;

[0094] For multiple receiving-end electric field line angles, the truncated average method is used to first remove the maximum and minimum values, and then the average value of the remaining receiving-end electric field line angles is calculated to obtain the accurately measured receiving-end electric field line angle;

[0095] Based on the optimization problem of maximizing the signal-to-interference-noise ratio, the optimal receiving channel is calculated and obtained according to the angle between the electric field lines at the receiving end.

[0096] The working principle of the above technical solution is as follows: in order to realize a semicircular array structure composed of multiple L-shaped electrodes, accurately measure the directionality of the ground electric field signal and the power frequency interference signal, and select the optimal receiving channel based on the principle of optimal signal-to-interference-noise ratio, the present invention first arranges ground electrode arrays in different directions at the receiving end to test and obtain multiple receiving end ground electric field line direction angles; then, for the multiple receiving end ground electric field line direction angles, the truncated average method is used to first remove the maximum and minimum values, and then the average value of the remaining receiving end ground electric field line direction angles is calculated to obtain the accurately measured receiving end ground electric field line direction angle; finally, based on the set optimization problem of maximizing the signal-to-interference-noise ratio, the optimal receiving channel is calculated and obtained according to the receiving end ground electric field line direction angle.

[0097] The beneficial effect of the above technical solution is as follows: by adopting the solution provided in this embodiment, the directionality of the geoelectric field signal and the power frequency interference signal is accurately measured based on a semicircular array structure composed of multiple L-shaped electrodes, and the optimal receiving channel is selected based on the principle of optimal signal-to-interference-noise ratio, thereby ensuring that the optimal receiving channel is obtained.

[0098] In one embodiment, an array of ground electrodes in different directions is arranged at the receiving end to test and obtain multiple angles of electric field lines at the receiving end, including:

[0099] like Figure 6 As shown, 2m buried electrodes are first used to form a semicircular array ground electrode detection device, which consists of 2m-1 channels, or m orthogonal detection channels, that is, m L-shaped electrode groups; where the distance between electrode No. 0 and the other electrodes is 1 meter; here m is 4;

[0100] Measure and calculate the angle α between the direction of the geoelectric field line of the i-th L-shaped electrode group and the line connecting channel 1 si , and the angle α between the ith power frequency interference signal and the line connecting channel 1 ni ;

[0101]

[0102]

[0103] α si represents the deviation angle of the i-th geoelectric field signal relative to the direction of channel 1; α ni Indicates the deviation angle of the i-th power frequency interference signal relative to the direction of channel 1.

[0104] The working principle of the above technical solution is as follows: In order to realize the arrangement of ground electrode arrays in different directions at the receiving end to test and obtain the angles of the directions of the electric field lines at multiple receiving ends, the present invention first uses 2m buried electrodes to form a semicircular array ground electrode detection device, which is composed of 2m-1 channels, or m orthogonal detection channels, that is, composed of m L-shaped electrode groups; wherein the distance between electrode No. 0 and the other electrodes is 1 meter; then measure and calculate the angle α of the direction of the electric field line of the i-th L-shaped electrode group relative to the line connecting channel 1. si , and the angle α between the ith power frequency interference signal and the line connecting channel 1 ni ;

[0105]

[0106] α si represents the deviation angle of the i-th geoelectric field signal relative to the direction of channel 1; α ni Indicates the deviation angle of the i-th power frequency interference signal relative to the direction of channel 1.

[0107] The beneficial effect of the above technical solution is that: by adopting the solution provided by this embodiment, by arranging ground electrode arrays in different directions at the receiving end, multiple accurate angles of the electric field lines at the receiving end can be tested and obtained.

[0108] In one embodiment, for multiple receiving-end electric field line direction angles, a truncated average method is used to first remove the maximum and minimum values, and then the average value of the remaining receiving-end electric field line direction angles is calculated to obtain a precisely measured receiving-end electric field line direction angle, including:

[0109] Get m geoelectric field signals with an angle of δ s1 , δ s2 ,...,δ sm , the final average angle δ of the geoelectric field signal relative to the positive direction of the x-axis s for:

[0110]

[0111] The measured angle of m power frequency interference signals is δ n1 , δ n2 ,...,δ nm , the final average angle δ of the power frequency interference signal relative to the positive direction of the x-axis n for:

[0112]

[0113] The working principle of the above technical solution is: in order to realize the angle of the direction of the electric field line of multiple receiving ends, the truncated average method is used to first remove the maximum and minimum values, and then calculate the average value of the remaining angles of the direction of the electric field line of the receiving end to obtain the accurately measured angle of the direction of the electric field line of the receiving end. The present invention first obtains m electric field signals with an angle of δ s1 , δ s2 ,...,δ sm , the final average angle δ of the geoelectric field signal relative to the positive direction of the x-axis s for:

[0114]

[0115] Then obtain the measured angle of m power frequency interference signals as δ n1 , δ n2 ,...,δ nm , the final average angle δ of the power frequency interference signal relative to the positive direction of the x-axis n for:

[0116]

[0117] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, the maximum and minimum values are first removed by the truncated average method, and then the average value of the remaining electric field line direction angle of the receiving end is calculated, so as to obtain the accurately measured electric field line direction angle of the receiving end.

[0118] In one embodiment, based on a set optimization problem of maximizing the signal-to-interference-and-noise ratio, an optimal receiving channel is calculated and obtained according to the angle between the directions of the electric field lines at the receiving end;

[0119] Set up an optimization problem to maximize the signal-to-interference-noise ratio; the optimization problem is:

[0120]

[0121] The constraints are: s ∈[0, 180°], where δ e is the angle between the connection direction of the electrode of a single channel and the positive direction of the x-axis; the optimal electrode placement direction when the signal-to-interference-noise ratio reaches the maximum value is obtained according to the optimization problem. At this time, select Compare the two channels with the smallest angle and their corresponding f(δ e ) value, and select the larger one as the receiving channel; where,

[0122]

[0123] The working principle of the above technical solution is as follows: in order to achieve the optimization problem of maximizing the signal-to-interference-and-noise ratio based on the setting, the optimal receiving channel is calculated and obtained according to the angle between the electric field lines at the receiving end. The present invention first sets the optimization problem of maximizing the signal-to-interference-and-noise ratio. The optimization problem is:

[0124]

[0125] The constraints are: s ∈[0, 180°], where δ e is the angle between the connection direction of the electrode of a single channel and the positive direction of the x-axis; the optimal electrode placement direction when the signal-to-interference-noise ratio reaches the maximum value is obtained according to the optimization problem. At this time, select Compare the two channels with the smallest angle and their corresponding f(δ e ) value, and select the larger one as the receiving channel; where,

[0126]

[0127] The beneficial effect of the above technical solution is that, by adopting the solution provided by this embodiment, an accurate receiving channel can be obtained through an optimization problem based on maximizing the signal-to-interference-and-noise ratio.

[0128] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A ground electrode current field optimal receiving system, characterized in that: include: The coarse detection module is used to roughly detect the directionality of the earth's electric field signal and the power frequency interference signal based on the designed orthogonal L-shaped electrode array; it includes: An orthogonal L-shaped ground electrode array is formed based on three buried electrodes; the three buried electrodes include electrode 0, electrode 1 and electrode 2; Based on the orthogonal L-shaped ground electrode array, a detection channel is formed; the detection channel includes channel 1 and channel 2; among them, electrode 0 and electrode 1 are connected to the detection device through a wire to form channel 1, and electrode 0 and electrode 2 are connected to the detection device through a wire to form channel 2; electrode 0 is connected to the positive electrode of channel 1 and the positive electrode of channel 2 respectively, electrode 1 is connected to the negative electrode of channel 1, and electrode 2 is connected to the negative electrode of channel 2; Based on the initial phase difference and amplitude of the geoelectric field signal, as well as the initial phase difference and amplitude of the power frequency interference signal obtained by detecting the detection channel, the directionality of the geoelectric field signal and the power frequency interference signal is roughly detected; The precision inspection module is used to accurately measure the directionality of geoelectric field signals and power frequency interference signals based on a semicircular array structure composed of multiple L-shaped electrode groups, and select the best receiving channel based on the principle of optimal signal-to-interference-noise ratio. It includes: Arrange ground electrode arrays in different directions at the receiving end to test and obtain the angles of the electric field lines at multiple receiving ends; For multiple receiving-end electric field line angles, the truncated average method is used to first remove the maximum and minimum values, and then the average value of the remaining receiving-end electric field line angles is calculated to obtain the accurately measured receiving-end electric field line angle; Based on the optimization problem of maximizing the signal-to-interference-noise ratio, the optimal receiving channel is calculated and obtained according to the precisely measured angle of the electric field lines at the receiving end.

2. The ground electrode current field optimal receiving system according to claim 1, characterized in that: An orthogonal L-shaped ground electrode array is formed based on a design of three buried electrodes, including: driving three metal electrodes into the ground at a certain distance, and detecting the geoelectric field signal in the ground through the metal electrodes.

3. The ground electrode current field optimal receiving system according to claim 1, characterized in that: Roughly detect the directionality of the geoelectric field signal and the power frequency interference signal, including: Detect the direction of the geoelectric field signal according to the detection channel; Detect the direction of the power frequency interference signal according to the detection channel.

4. The ground electrode current field optimal receiving system according to claim 3, characterized in that: Detect the direction of the geoelectric field signal based on the detection channel, including: After intercepting the geoelectric field signal at the same starting sampling points, the area where the geoelectric field line is located is determined by the initial phase relationship of the geoelectric field signal of the detection channel, and then the angle between the direction of the geoelectric field line and the line connecting electrodes 0 and 1 is determined by the following formula: , to obtain the direction of the geoelectric field signal; in, is the electric field strength from electrode 0 to electrode 1, is the electric field strength from electrode 0 to electrode 2.

5. The ground electrode current field optimal receiving system according to claim 3, characterized in that: Detect the direction of the power frequency interference signal based on the detection channel, including: Use a bandpass filter to extract the 50Hz power frequency interference signal and obtain the data of the first 10 seconds of the power frequency interference signal; calculate the angle between the direction with the maximum intensity of the power frequency interference signal and channel 1 using the following formula ; For channel 1 The voltage amplitude of the power frequency interference signal received within seconds, For channel 2 The voltage amplitude of the power frequency interference signal received within seconds; For the moment The angle between the direction with the maximum power frequency interference signal intensity corresponding to 1 second and channel 1.

6. The ground electrode current field optimal receiving system according to claim 1, characterized in that: For multiple receiving-end electric field line angles, the truncated average method is used to first remove the maximum and minimum values, and then calculate the average value of the remaining receiving-end electric field line angles to obtain the accurately measured receiving-end electric field line angle, including: Get the angle of m geoelectric field signals: , ,..., , the final average angle of the geoelectric field signal relative to the positive direction of the x-axis for: The measured angle of m power frequency interference signals is obtained as , ,..., , the final average angle of the power frequency interference signal relative to the positive direction of the x-axis for: 。 7. The ground electrode current field optimal receiving system according to claim 6, characterized in that: Based on the optimization problem of maximizing the signal-to-interference-noise ratio, the optimal receiving channel is calculated and obtained according to the precisely measured angle of the electric field lines at the receiving end. Set up an optimization problem to maximize the signal-to-interference-noise ratio; the optimization problem is: The constraints are: ,in, is the angle between the connection direction of the electrode of a single channel and the positive direction of the x-axis; the optimal electrode placement direction when the signal-to-interference-noise ratio reaches the maximum value is obtained according to the optimization problem. ; At this time, select Compare the two channels with the smallest angle and their corresponding The value of , and select the larger one as the receiving channel; among them, 。

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