Electromagnetic observation method and device based on electromagnetic field equivalent impedance

Abstract

The present invention relates to an electromagnetic observation method and device based on electromagnetic field equivalent impedance. The method comprises: selecting a construction area for a detection task as a measurement area based on preset detection task requirements; arranging measurement points in the measurement area based on the detection task and preset lateral resolution requirements; obtaining location and topographic information of the measurement area, deploying field sources for artificial source electromagnetic method based on the location and topographic information, collecting horizontal electric field component data and orthogonal horizontal magnetic field component data at the measurement points; calculating horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data, calculating equivalent impedance based on the horizontal electric field component data and the horizontal total magnetic field data; and calculating wide-azimuth apparent resistivity based on the equivalent impedance. This method expands the observable range of the artificial source electromagnetic method and improves the flexibility of data collection at the measurement points.

Description

Technical Field

[0001] The present invention belongs to the field of geophysical exploration, and in particular relates to an electromagnetic observation method and device based on electromagnetic field equivalent impedance. Background Art

[0002] Lead wires from the transmitting system consisting of the generator and the instrument are grounded at A and B respectively, forming a loop with the earth. A and B are respectively composed of several electrodes. The material of the electrodes is generally aluminum plate, but can also be copper rod, etc. Figure 1 The diagram below shows a traditional observation setup. Current is sent underground through points A and B, known as the field source (i.e., the source of the electromagnetic field). A rectangular coordinate system is established with the midpoint of the field source as the origin, where x is parallel to AB, y is perpendicular to AB, and z is perpendicular to the surface and downward.

[0003] The artificial source electromagnetic method sends currents of different frequencies into the ground through a field source, then collects electromagnetic field signals of the same frequency at a distance and analyzes the signals to obtain the properties of the underground medium.

[0004] The electric field components are collected by extending wires from the measuring instrument and grounding them on either side of the measuring point, forming a potential difference measurement device. The midpoint of the line connecting the two grounding points is the measuring point, and the electric field is calculated from the measured potential difference. The angle between the line connecting the two grounding points and the x-axis represents the difference in electric field components. For example, Ex indicates an angle of 0, 180, or 360 degrees, and Ey indicates an angle of 90 or 270 degrees. The electric field has only a horizontal component, so only changes in the horizontal direction, i.e., the xoy plane, need to be considered.

[0005] Magnetic field components are collected directly at the measurement point using a magnetic field sensor (magnetic rod, fluxgate, etc.). The angle between the sensor's orientation and the x-axis represents the magnetic field component, similar to the electric field. The magnetic field has three directional components, and we need to consider both horizontal and vertical variations, i.e., three-dimensional space.

[0006] When collecting electromagnetic field signals, the observation device of the conventional artificial source electromagnetic method can only collect the field intensity within a specific azimuth angle of the field source (60 degrees on both sides), and can only collect specific electromagnetic field components at the measuring point, including the electric field component E x 、E y , magnetic field component H x 、H y 、H z Fifth, traditional observation devices have low utilization rates of field sources. Under complex terrain conditions, on the one hand, it is difficult to select a suitable field source location, and on the other hand, it is difficult to ensure the accuracy of the electromagnetic field components, resulting in low observation accuracy or even inability to carry out observations. Summary of the Invention

[0007] In order to remedy the deficiencies of the prior art, the present invention provides an electromagnetic observation method and device based on electromagnetic field equivalent impedance.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] In a first aspect, an electromagnetic observation method based on electromagnetic field equivalent impedance is provided, comprising:

[0010] According to the preset detection task requirements, select the construction area of ​​the detection task as the measurement area;

[0011] Arrange measurement points in the survey area according to the detection task and preset lateral resolution requirements;

[0012] Obtain the location and terrain information of the survey area and arrange the source of the artificial source electromagnetic method according to the location and terrain information;

[0013] Collect horizontal electric field component data and orthogonal horizontal magnetic field component data at the measuring point;

[0014] Horizontal total magnetic field data is calculated based on the orthogonal horizontal magnetic field component data, and equivalent impedance is calculated based on the horizontal electric field component data and the horizontal total magnetic field data;

[0015] The wide-azimuth apparent resistivity is calculated based on the equivalent impedance.

[0016] Furthermore, the measuring points are distributed in a linear manner, a regular mesh distribution or an irregular mesh distribution.

[0017] Furthermore, the location and topographic information of the survey area is obtained, and the field source of the artificial source electromagnetic method is arranged according to the location and topographic information, including:

[0018] Get the survey area location of the survey area;

[0019] Obtain the surrounding terrain conditions of the survey area according to the survey area location to obtain the location terrain information;

[0020] Select the target area for field source deployment in the survey area according to the location terrain information. There is no water in the target area and the terrain undulation does not exceed the preset severity.

[0021] Based on the artificial source electromagnetic method, a transmitting system that transmits current is deployed in the target area to form a field source.

[0022] Furthermore, based on the artificial source electromagnetic method, a transmitting system for transmitting current is arranged in the target area to form a field source, including:

[0023] Arranging a first field source electrode and a second field source electrode in the target area based on an artificial source electromagnetic method;

[0024] Connecting a transmitting instrument that generates a current of a preset frequency to the first field source electrode and the second field source electrode wire to obtain a transmitting system;

[0025] The current of the preset frequency generated by the transmitting instrument is transmitted underground through the first field source electrode and the second field source electrode to form a field source.

[0026] Furthermore, horizontal electric field component data and orthogonal horizontal magnetic field component data are collected at the measuring point, including:

[0027] Get the receiving and transmitting distance from the measuring point to the midpoint of the line between the first field source electrode and the second field source electrode r , wherein the first field source electrode and the second field source electrode generate a current I ;

[0028] Get the receiving and transmitting angles of the line connecting the measuring point and the midpoint and the line connecting the first field source electrode and the second field source electrode φ , and the electric field component angle between the measuring point and the horizontal electric field α , horizontal electric field x The axis coincides with the line connecting the first field source electrode and the second field source electrode, and the horizontal electric field y Axis and x axis vertical;

[0029] pass x Calculation formula of axial electric field component , calculated x Axis electric field component data E x ; dL is the distance between the first field source electrode and the second field source electrode, k is the wave number, , is the circular frequency, is the magnetic permeability, is the conductivity, is the dielectric constant, represents an imaginary unit;

[0030] pass y Calculation formula of axial electric field component , calculated y Axis electric field component data E y ;

[0031] according to x Axis electric field component data E x and y Axis electric field component data E y , calculate the horizontal electric field component data ;

[0032] An orthogonal two-component magnetic sensor is used to collect first orthogonal horizontal magnetic field component data H1 and second orthogonal horizontal magnetic field component data H2 of the measuring point.

[0033] Furthermore, the horizontal total magnetic field data is calculated based on the orthogonal horizontal magnetic field component data, and the equivalent impedance is calculated based on the horizontal electric field component data and the horizontal total magnetic field data, including:

[0034] The horizontal total magnetic field data is calculated based on the first orthogonal horizontal magnetic field component data H1 and the second orthogonal horizontal magnetic field component data H2. ;

[0035] The horizontal electric field component data E α Substitute the horizontal total magnetic field data H into the equivalent impedance calculation formula , calculate the equivalent impedance Z e .

[0036] Furthermore, the wide-azimuth apparent resistivity is calculated based on the equivalent impedance, including:

[0037] Based on the calculation formula of wide azimuth apparent resistivity , the equivalent impedance Z e Substitute and calculate the wide azimuth apparent resistivity ;

[0038] is the electromagnetic effect function of the horizontal electric field, and its expression is:

[0039] ;

[0040] F H is the electromagnetic effect function of the horizontal total magnetic field, and its expression is:

[0041] ;

[0042] in, ;

[0043] ;

[0044] Iv 、 Kv Respectively v Bessel functions of the first and second kind.

[0045] In a second aspect, an electromagnetic observation device based on electromagnetic field equivalent impedance is provided, comprising:

[0046] The measurement area selection module is used to select the construction area of ​​the detection task as the measurement area according to the preset detection task requirements;

[0047] The measuring point arrangement module is used to arrange measuring points in the measuring area according to the detection task and the preset lateral resolution requirements;

[0048] The field source layout module is used to obtain the location and terrain information of the survey area and to layout the field source of the artificial source electromagnetic method based on the location and terrain information;

[0049] A data acquisition module is used to collect horizontal electric field component data and orthogonal horizontal magnetic field component data at the measuring point;

[0050] An equivalent impedance calculation module is used to calculate horizontal total magnetic field data based on orthogonal horizontal magnetic field component data, and to calculate equivalent impedance based on horizontal electric field component data and horizontal total magnetic field data;

[0051] The electromagnetic observation module is used to calculate the wide-azimuth apparent resistivity based on the equivalent impedance.

[0052] The beneficial effects achieved by the present invention are:

[0053] The electromagnetic observation method based on electromagnetic field equivalent impedance of the present invention selects the construction area of ​​the detection task as the measurement area according to the preset detection task requirements; arranges measurement points in the measurement area according to the detection task and the preset lateral resolution requirements; obtains the location and topographic information of the measurement area, arranges the field source of the artificial source electromagnetic method according to the location and topographic information, collects horizontal electric field component data and orthogonal horizontal magnetic field component data at the measurement points; calculates horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data; calculates horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data, calculates equivalent impedance based on the horizontal electric field component data and the horizontal total magnetic field data; and calculates wide-azimuth apparent resistivity based on the equivalent impedance. Compared with the traditional artificial source electromagnetic method that can only collect electromagnetic field components in a specific direction at the measurement point, the present invention can combine the terrain to observe within any horizontal electromagnetic azimuth angle of the horizontal electric field, provide flexibility in the selection of the field source position, improve the flexibility of measuring point data collection, and solve the shortcomings of the traditional artificial source electromagnetic method with a small observation range, strict observation device system requirements, and inflexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a schematic diagram of observation using a traditional observation device;

[0055] Figure 2 This is a flow chart of the electromagnetic observation method based on electromagnetic field equivalent impedance of the present invention;

[0056] Figure 3 Schematic diagram of electromagnetic observation based on electromagnetic field equivalent impedance of the present invention;

[0057] Figure 4 is the electric field component angle of the present invention α and transmit and receive angles φand the logarithm of horizontal electric field component data lg E relationship diagram;

[0058] Figure 5 Schematic diagram of collecting orthogonal horizontal magnetic field components at measuring points of the present invention;

[0059] Figure 6 This is a structural diagram of the electromagnetic observation device based on electromagnetic field equivalent impedance of the present invention. DETAILED DESCRIPTION

[0060] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0061] like Figure 2 As shown, an embodiment of the present invention provides an electromagnetic observation method based on electromagnetic field equivalent impedance, including:

[0062] 201, according to the preset detection task requirements, select the construction area of ​​the detection task as the measurement area;

[0063] The preset exploration mission requirements include the general area to be explored and the target to be explored, such as rock layers, oil and gas layers, water layers, minerals, etc. Once the exploration mission is known, the explorer will know the data requirements for the mission in advance. Therefore, the construction area of ​​the exploration mission can be selected as the survey area according to the preset exploration mission requirements.

[0064] 202. Arrange measurement points in the measurement area according to the detection task and the preset lateral resolution requirements;

[0065] Among them, after determining the scope of the survey area, it is necessary to arrange the measuring points in the survey area, and set the position and number of the measuring points according to the detection task and the preset lateral resolution requirements. In the field of electromagnetic detection, lateral resolution is the ability to distinguish the minimum distance between two adjacent geological bodies in the horizontal direction, measured in length. It is related to factors such as the arrangement of the measuring points in the horizontal direction, the nature of the source signal, and the physical properties of the detected target. The smaller the value, the higher the lateral resolution. Figure 3 The figure shows a schematic diagram of electromagnetic observation based on electromagnetic field equivalent impedance according to the present invention, wherein the distribution of measuring points is not the distribution mode of the traditional artificial source electromagnetic method, but can be linear distribution, regular mesh distribution or irregular mesh distribution.

[0066] 203, obtaining location and topographic information of the survey area, and deploying the field source of the artificial source electromagnetic method according to the location and topographic information;

[0067] The specific source layout process is as follows:

[0068] First, obtain the survey area location. The survey area location is actually the geographical location, which can be reflected by the latitude and longitude information.

[0069] Obtain the surrounding terrain conditions of the survey area based on the survey area location. The surrounding terrain conditions can be obtained by viewing the data in the geo-hydrological information database or local map data to obtain the location terrain information;

[0070] Select the target area for field source deployment within the measurement area based on the location and terrain information. The target area should be free of water and the terrain should not exceed the preset level of undulation. This is because water can affect the electric field, and undulating terrain can also affect measurement accuracy.

[0071] Based on the artificial source electromagnetic method, a transmitting system that transmits current is deployed in the target area to form a field source; Figure 3 As shown, based on the artificial source electromagnetic method, the first field source electrode A and the second field source electrode B are arranged in the target area; electrode pits are dug at A and B, aluminum plates are buried, the plates are led out by wires, salt water is poured and buried;

[0072] Connect the transmitting instrument that generates the current of the preset frequency to the first field source electrode A and the second field source electrode B to obtain a transmitting system; transmit the current of the preset frequency generated by the transmitting instrument to the ground through the first field source electrode and the second field source electrode to form a field source. Figure 3 It can be seen that the field source can be at any orientation of the measuring point, which has a wider range than the traditional artificial source electromagnetic method.

[0073] 204, collecting horizontal electric field component data and orthogonal horizontal magnetic field component data at the measuring point;

[0074] Electromagnetic detection uses electrodes or sensors placed on the ground to receive electromagnetic signals from underground media, specifically using orthogonal two-component magnetic sensors, to infer the underground geological structure. Topographic conditions, such as topography and variations in surface resistivity, can affect the propagation and reception of electromagnetic signals. Large topographical fluctuations can cause signal attenuation, and variations in surface resistivity can affect the signal propagation path and strength. Therefore, it is necessary to obtain topographical information at the measuring point. The target orientation of the magnetic field sensor at each measuring point is set based on this topographical information. For example, if the magnetic field sensor is a hollow coil, the coil's orientation is the target orientation.

[0075] The specific process of collecting horizontal electric field component data at the measuring point is as follows:

[0076] like Figure 4 The electric field component angles are shown α and transmit and receive angles φ and the logarithm of horizontal electric field component data lg E If the electric field component angle is selected α and transmit and receive angles φ The corresponding horizontal electric field component data logarithm lg E If the value of is too small, the data signal-to-noise ratio will be very poor, for example Figure 4 The blue area outside the dotted line is the area that is not suitable for collecting electric field components. Therefore, the electric field component angle outside the dotted line area cannot be selected. α and transmit and receive angles φ ;

[0077] Get the receiving and transmitting distance from the measuring point to the midpoint of the line between the first field source electrode and the second field source electrode r , wherein the first field source electrode and the second field source electrode generate a current I ;

[0078] Get the receiving and transmitting angles of the line connecting the measuring point and the midpoint and the line connecting the first field source electrode and the second field source electrode φ , and the electric field component angle between the measuring point and the horizontal electric field α , horizontal electric field x The axis coincides with the line connecting the first field source electrode and the second field source electrode, and the horizontal electric field y Axis and x axis vertical;

[0079] pass x Calculation formula of axial electric field component , calculated x Axis electric field component data E x ; dL is the distance between the first field source electrode and the second field source electrode, k is the wave number, , w is the circular frequency, is the magnetic permeability, is the conductivity, is the dielectric constant, represents an imaginary unit;

[0080] pass y Calculation formula of axial electric field component , calculated y Axis electric field component data E y ;

[0081] according to x Axis electric field component data E x and y Axis electric field component data E y , calculate the horizontal electric field component data ;

[0082] The process of collecting the orthogonal horizontal magnetic field component data of the measuring point is:

[0083] Use an orthogonal two-component magnetic sensor to collect first orthogonal horizontal magnetic field component data H1 and second orthogonal horizontal magnetic field component data H2 of the measuring point;

[0084] Figure 5 The figure shows the schematic diagram of collecting horizontal magnetic field components at the measuring point; the collected magnetic field components are determined by the direction and orientation of the magnetic field sensor. x The angle between the axes is determined. x The axis is determined by the line connecting the field source electrode A and the field source electrode B. Figure 5 The magnetic field collected by the two horizontal axial coils of the orthogonal two-component magnetic sensor is the orthogonal horizontal magnetic field components H1 and H2.

[0085] 205, calculating horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data, and calculating equivalent impedance based on the horizontal electric field component data and the horizontal total magnetic field data;

[0086] According to the above first orthogonal horizontal magnetic field component data H1 and second orthogonal horizontal magnetic field component data H2, the horizontal total magnetic field data is calculated. , the horizontal electric field component data E α Substitute the horizontal total magnetic field data H into the equivalent impedance calculation formula , calculate the equivalent impedance Z e .

[0087] 206, the wide-azimuth apparent resistivity is calculated based on the equivalent impedance.

[0088] Among them, according to the calculation formula of wide azimuth apparent resistivity , the equivalent impedance Z e Substitute and calculate the wide azimuth apparent resistivity ;

[0089] is the electromagnetic effect function of the horizontal electric field, and its expression is:

[0090] ;

[0091] F H is the electromagnetic effect function of the horizontal total magnetic field, and its expression is:

[0092] ;

[0093] in, ;

[0094] ;

[0095] Iv 、 Kv Respectively v Bessel functions of the first and second kind.

[0096] The beneficial effects of the embodiments of the present invention are:

[0097] According to the preset detection task requirements, the construction area of ​​the detection task is selected as the measurement area; the measurement points are arranged in the measurement area according to the detection task and the preset lateral resolution requirements; the location and topographic information of the measurement area is obtained, and the field source of the artificial source electromagnetic method is arranged according to the location and topographic information, and the horizontal electric field component data and the horizontal magnetic field component data are collected at the measurement points; the horizontal total magnetic field data is calculated based on the orthogonal horizontal magnetic field component data, and the equivalent impedance is calculated based on the horizontal electric field component data and the horizontal total magnetic field data; the wide-azimuth apparent resistivity is calculated based on the equivalent impedance. Compared with the traditional artificial source electromagnetic method that can only collect electromagnetic field components in a specific direction at the measurement point, the present invention can be combined with the terrain to observe within any horizontal electromagnetic azimuth angle of the horizontal electric field, providing flexibility in the selection of the field source position, improving the flexibility of the measurement point when collecting data, and solving the defects of the traditional artificial source electromagnetic method with a small observation range, strict requirements on the observation device system, and inflexibility.

[0098] In combination with the electromagnetic observation method based on electromagnetic field equivalent impedance described in the above embodiments, an electromagnetic observation system based on electromagnetic field equivalent impedance is described below through an embodiment.

[0099] like Figure 6 As shown, an embodiment of the present invention provides an electromagnetic observation device based on electromagnetic field equivalent impedance, comprising:

[0100] The measurement area selection module 601 is used to select the construction area of ​​the detection task as the measurement area according to the preset detection task requirements;

[0101] The measuring point arrangement module 602 is used to arrange measuring points in the measuring area according to the detection task and the preset lateral resolution requirement;

[0102] The source layout module 603 is used to obtain the location and terrain information of the survey area and to layout the source of the artificial source electromagnetic method according to the location and terrain information;

[0103] The data acquisition module 604 is used to collect horizontal electric field component data and orthogonal horizontal magnetic field component data at the measuring point;

[0104] An equivalent impedance calculation module 605 is configured to calculate horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data, and calculate equivalent impedance based on the horizontal electric field component data and the horizontal total magnetic field data;

[0105] The electromagnetic observation module 606 is used to calculate the wide-azimuth apparent resistivity based on the equivalent impedance.

[0106] The beneficial effects of the embodiments of the present invention are:

[0107] The survey area selection module 601 selects the construction area of ​​the survey task as the survey area based on the preset survey task requirements. The survey point layout module 602 arranges survey points in the survey area based on the survey task and the preset lateral resolution requirements. The field source layout module 603 obtains the location and topographic information of the survey area and arranges the artificial source electromagnetic method field source based on the location and topographic information. The field source is used to emit current. The data acquisition module 604 collects horizontal electric field component data and orthogonal horizontal magnetic field component data at the survey points. The equivalent impedance calculation module 605 calculates horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data, and calculates equivalent impedance based on the horizontal electric field component data and the horizontal total magnetic field data. The electromagnetic observation module 606 calculates the wide-azimuth apparent resistivity based on the equivalent impedance. Compared with the traditional artificial source electromagnetic method, which can only collect electromagnetic field components in specific directions at the survey point, the present invention can observe the horizontal electric field in any horizontal electromagnetic azimuth angle according to the terrain. This provides flexibility in the selection of field source locations and improves the flexibility of survey point data collection. It overcomes the shortcomings of the traditional artificial source electromagnetic method, such as the limited observation range, strict observation device system requirements, and inflexibility.

[0108] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0109] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0110] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0112] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. An electromagnetic observation method based on electromagnetic field equivalent impedance, characterized in that: include: According to the preset detection task requirements, select the construction area of ​​the detection task as the measurement area; Arrange measurement points in the measurement area according to the detection task and the preset lateral resolution requirement; Acquiring location and topographic information of the survey area, and deploying the field source of the artificial source electromagnetic method according to the location and topographic information; The field source is formed by current emitted by the first field source electrode and the second field source electrode; collecting horizontal electric field component data and orthogonal horizontal magnetic field component data at the measuring point; Calculate horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data, and calculate equivalent impedance based on the horizontal electric field component data and the horizontal total magnetic field data; Obtaining wide-azimuth apparent resistivity based on the equivalent impedance calculation; The collecting of horizontal electric field component data and orthogonal horizontal magnetic field component data at the measuring point includes: Obtaining a transmitting and receiving distance r from the measuring point to a midpoint of a line connecting the first field source electrode and the second field source electrode, wherein the first field source electrode and the second field source electrode generate a current I; obtaining a transmitting and receiving angle φ between a line connecting the measuring point and the midpoint and a line connecting the first field source electrode and the second field source electrode, and an electric field component angle α between the measuring point and a horizontal electric field, wherein an x-axis of the horizontal electric field coincides with a line connecting the first field source electrode and the second field source electrode, and a y-axis of the horizontal electric field is perpendicular to the x-axis; The x-axis electric field component is calculated by the formula , calculate the x-axis electric field component data E x ; dL is the distance between the first field source electrode and the second field source electrode, k is the wave number, , is the circular frequency, μ is the magnetic permeability, is the conductivity, ε is the dielectric constant, and i represents an imaginary unit; The y-axis electric field component is calculated by the formula , calculate the y-axis electric field component data E y ; According to the x-axis electric field component data E x and the y-axis electric field component data E y , calculate the horizontal electric field component data ; An orthogonal two-component magnetic sensor is used to collect first orthogonal horizontal magnetic field component data H1 and second orthogonal horizontal magnetic field component data H2 of the measuring point.

2. The electromagnetic observation method based on electromagnetic field equivalent impedance according to claim 1, characterized in that: The measuring points are distributed in a linear manner, a regular mesh distribution or an irregular mesh distribution.

3. The electromagnetic observation method based on electromagnetic field equivalent impedance according to claim 1, characterized in that: The obtaining of location and topographic information of the survey area and the deployment of the field source of the artificial source electromagnetic method according to the location and topographic information include: Obtaining a measurement area position of the measurement area; Acquire the surrounding terrain conditions of the survey area according to the location of the survey area to obtain location terrain information; Selecting a target area for field source deployment in the survey area according to the location terrain information, wherein the target area has no water area and the terrain undulation does not exceed a preset severity; Based on the artificial source electromagnetic method, an emission system for emitting current is arranged in the target area to form a field source.

4. The electromagnetic observation method based on electromagnetic field equivalent impedance according to claim 3, characterized in that: The transmitting system for arranging the transmitting current in the target area based on the artificial source electromagnetic method to form a field source includes: Arranging the first field source electrode and the second field source electrode in the target area based on an artificial source electromagnetic method; Connecting a transmitting instrument that generates a current of a preset frequency to the first field source electrode and the second field source electrode wires to obtain a transmitting system; The current of the preset frequency generated by the transmitting instrument is transmitted underground through the first field source electrode and the second field source electrode to form a field source.

5. The electromagnetic observation method based on electromagnetic field equivalent impedance according to claim 4, characterized in that: The calculating of the horizontal total magnetic field data according to the orthogonal horizontal magnetic field component data, and the calculating of the equivalent impedance according to the horizontal electric field component data and the horizontal total magnetic field data, include: The horizontal total magnetic field data is calculated based on the first orthogonal horizontal magnetic field component data H1 and the second orthogonal horizontal magnetic field component data H2. ; The horizontal electric field component data E α Substitute the horizontal total magnetic field data H into the equivalent impedance calculation formula , calculate the equivalent impedance Z e .

6. The electromagnetic observation method based on electromagnetic field equivalent impedance according to claim 5, characterized in that: The calculating the wide-azimuth apparent resistivity according to the equivalent impedance includes: Based on the calculation formula of wide azimuth apparent resistivity , the equivalent impedance Z e Substitute and calculate the wide azimuth apparent resistivity ; described is the electromagnetic effect function of the horizontal electric field, and its expression is: ； The F H is the electromagnetic effect function of the horizontal total magnetic field, and its expression is: ； Among them, the ; described ; Iv and Kv represent the first and second Bessel functions of order v, respectively.

7. An electromagnetic observation device based on electromagnetic field equivalent impedance, characterized in that: include: The measurement area selection module is used to select the construction area of ​​the detection task as the measurement area according to the preset detection task requirements; A measuring point arrangement module, configured to arrange measuring points in the measuring area according to the detection task and a preset lateral resolution requirement; A field source layout module is used to obtain the location and topographic information of the survey area and to arrange the field source of the artificial source electromagnetic method according to the location and topographic information; The field source is formed by current emitted by the first field source electrode and the second field source electrode; A data acquisition module, configured to acquire horizontal electric field component data and orthogonal horizontal magnetic field component data at the measuring point; an equivalent impedance calculation module, configured to calculate horizontal total magnetic field data based on the orthogonal horizontal magnetic field component data, and calculate equivalent impedance based on the horizontal electric field component data and the horizontal total magnetic field data; An electromagnetic observation module, configured to calculate a wide-azimuth apparent resistivity based on the equivalent impedance; The data acquisition module is specifically configured to obtain a transmission / reception distance r from the measuring point to a midpoint of a line connecting the first field source electrode and the second field source electrode, wherein the first field source electrode and the second field source electrode generate a current I; obtain a transmission / reception angle φ between a line connecting the measuring point and the midpoint and a line connecting the first field source electrode and the second field source electrode, and an electric field component angle α between the measuring point and a horizontal electric field, wherein the x-axis of the horizontal electric field coincides with the line connecting the first field source electrode and the second field source electrode, and the y-axis of the horizontal electric field is perpendicular to the x-axis; and calculate the x-axis electric field component using the formula , calculate the x-axis electric field component data E x ; dL is the distance between the first field source electrode and the second field source electrode, k is the wave number, , is the circular frequency, μ is the magnetic permeability, is the conductivity, ε is the dielectric constant, and i represents an imaginary unit; The y-axis electric field component is calculated by the formula , calculate the y-axis electric field component data E y According to the x-axis electric field component data E x and the y-axis electric field component data E y , calculate the horizontal electric field component data ; Use an orthogonal two-component magnetic sensor to collect the first orthogonal horizontal magnetic field component data H1 and the second orthogonal horizontal magnetic field component data H2 of the measuring point.

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