CN117968644A - Seawater depth detection method based on electromagnetic field, storage medium and electronic equipment - Google Patents
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Abstract
The application provides a seawater depth detection method based on an electromagnetic field, a storage medium and electronic equipment, wherein the method comprises the following steps: acquiring an electric field and a magnetic field formed by a natural source or an artificial field source at a remote area observation point; based on the electric field and the magnetic field, determining apparent resistivity of the observation point; fitting a visual resistivity curve based on the visual resistivity of the observation point; and acquiring the seawater resistivity of the observation point, and determining the seawater depth of the observation point based on the seawater resistivity and the apparent resistivity curve. Therefore, the detection efficiency of the sea water depth can be effectively improved, and the method can provide a more suitable detection means under various different conditions in an actual detection scene as an effective complementary method and means of the existing mainstream detection method.
Description
Technical Field
The application relates to the technical field of sea water detection, in particular to a sea water depth detection method based on an electromagnetic field, a storage medium and electronic equipment.
Background
The ocean covers 71% of the earth's surface and is the second space for human survival. The vertical distance from the sea surface to the sea bottom is the sea water depth, and the topography of the sea bottom is intuitively reflected. Sea water depth is the basis for performing marine exploration, marine military operations, and other related problems.
Marine electromagnetic field refers to electromagnetic fields that exist in a marine environment due to a man-made or natural field source, including electric and magnetic fields, collectively referred to as marine electromagnetic fields. In the ocean development activities, a kind of radio waves have the characteristics of weakening, strong penetrating power and the like, have been widely focused in recent years, and are rapidly developed, so that the method can be widely applied to the fields of navigation, mineral exploration, underwater military target detection and the like.
According to the regulations of radio frequency division of the people's republic of China, the radio frequency of China is divided into 14 frequency bands from 0.03Hz to 3000GHz, and electromagnetic fields researched in marine environments are mainly concentrated in TLF, ELF, SLF, ULF (0.03 to 3000 Hz) and other frequency bands.
Currently, sea water depth detection means mainly comprise sonar, laser sounding, satellite height measurement gravity data inversion and remote sensing image inversion. Sonar and laser sounding, although the detection precision is high, an artificial source (an active detection mode) is needed, the efficiency is low, the cost is high, the laser sounding depth is limited (usually only tens of meters), and the gravity data inversion and the remote sensing image inversion are limited, although the artificial source is not needed, the detection depth is large (a passive/passive detection mode). Currently, active/passive electromagnetic sounding methods and means that can be effectively applied to different sea depths are not seen.
Disclosure of Invention
The embodiment of the application aims to provide a seawater depth detection method based on an electromagnetic field, a storage medium and electronic equipment, and a seawater depth detection scheme based on the electromagnetic field is constructed by fully excavating hidden information in the ocean electromagnetic field, so that the seawater depth is obtained through rapid calculation and is used as an effective complementary method and means of the existing mainstream detection method.
In order to achieve the above object, an embodiment of the present application is achieved by:
In a first aspect, an embodiment of the present application provides a method for detecting a depth of seawater based on an electromagnetic field, including: acquiring an electric field and a magnetic field formed by a natural source or an artificial field source at a remote area observation point; based on the electric field and the magnetic field, determining apparent resistivity of the observation point; fitting a visual resistivity curve based on the visual resistivity of the observation point; and acquiring the seawater resistivity of the observation point, and determining the seawater depth of the observation point based on the seawater resistivity and the apparent resistivity curve.
With reference to the first aspect, in a first possible implementation manner of the first aspect, determining a apparent resistivity of the observation point based on the electric field and the magnetic field includes:
The incident electric field and magnetic field formed by the natural source or artificial field source far zone are similar to plane wave normal incidence, and the wave impedance is as follows:
Wherein E x is the electric field horizontal component in the x direction; e y is the electric field horizontal component in the y direction; h x is the magnetic field horizontal component in the x direction; h y is the magnetic field horizontal component in the y-direction;
The apparent resistivity at the observation point is:
Where ρ s is apparent resistivity, ω is angular frequency, μ is permeability, and Z obs is wave impedance at the observation point.
With reference to the first aspect, in a second possible implementation manner of the first aspect, fitting a apparent resistivity curve based on the apparent resistivity of the observation point includes: and (5) performing primary data processing on the apparent resistivity, and fitting by adopting a cubic curve.
With reference to the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, obtaining a seawater resistivity of the observation point, and determining a seawater depth of the observation point based on the seawater resistivity and the apparent resistivity curve includes: acquiring the seawater resistivity of the observation point, and determining a seawater resistivity straight line based on the seawater resistivity; determining the first three intersection points of the apparent resistivity curve of the observation point and the seawater resistivity straight line; and calculating the sea water depth of the observation point based on the frequency at the at least one intersection point and the corresponding attenuation coefficient.
With reference to the third possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, calculating a sea water depth of the observation point based on a frequency at the at least one intersection point and a corresponding attenuation coefficient includes:
Determining the frequency f 1、f2、f3 of the first three intersection points and the corresponding attenuation coefficient alpha 1、α2、α3;
Substituting at least one set of f 1 and α 1、f2 and α 2、f3 and α 3 into the formula to calculate the sea water depth:
Wherein h w is the sea water depth, alpha i is the attenuation coefficient corresponding to the ith intersection point, f i is the frequency corresponding to the ith intersection point, ρ w is the sea water resistivity, and μ 0 is the vacuum magnetic permeability.
With reference to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner of the first aspect, calculating the sea water depth by substituting at least one set of f 1 and α 1、f2 and α 2、f3 and α 3 into a formula includes: f 1, alpha 1、f2, alpha 2、f3 and alpha 3 are respectively substituted into a formula to calculate the sea water depth, and three sea water depths h w1、hw2、hw3 are calculated; if the difference between every two of the h w1、hw2、hw3 is not more than the set proportion, calculating the average value of the h w1、hw2、hw3 as the sea water depth; if the difference between every two of the h w1、hw2、hw3 is larger than the set proportion, removing one seawater depth value with the largest difference with the other two, and calculating the average value between the two seawater depth values as the seawater depth.
With reference to the fourth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, the observation point has a seawater-seabed two-layer medium, the detected seawater depth is the thickness of the seawater of the first-layer medium, and the attenuation coefficient α i satisfies:
Where ω is angular frequency, μ is permeability of seawater, σ 1 is first layer medium conductivity, and h 1 is first layer medium thickness.
With reference to the sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the submarine medium is one or more layers.
In a second aspect, an embodiment of the present application provides a storage medium, where the storage medium is installed in a device, and includes a stored program, where the program, when executed, controls the device in which the storage medium is located to execute the electromagnetic field based sea water depth detection method according to any one of the first aspect or the possible implementation manners of the first aspect.
In a third aspect, an embodiment of the present application provides an electronic device, including a memory for storing information including program instructions, and a processor for controlling execution of the program instructions, wherein: the program instructions, when loaded and executed by a processor, implement the steps of the electromagnetic field based sea water depth detection method as described in any one of the first aspect or the possible implementation manners of the first aspect.
The beneficial effects are that:
1. Firstly, converting an electromagnetic field signal series through electric field and magnetic field signals formed at an observation point of a remote area by a natural source or an artificial field source acquired in the air or sea water to obtain a apparent resistivity curve of the observation point. And then carrying out theoretical deduction, and establishing a theoretical calculation formula for excavating the sea water depth according to the apparent resistivity curve, so that the sea water depth of the observation point can be determined based on the sea water resistivity and the apparent resistivity curve (combined with the theoretical calculation formula) after the sea water resistivity of the observation point is obtained. Therefore, the detection efficiency of the sea water depth can be effectively improved, and the method can provide a more suitable detection means under various different conditions in an actual detection scene as an effective complementary method and means of the existing mainstream detection method.
2. When the theoretical calculation formula constructed by deduction is utilized to calculate the sea water depth, three intersection points (the relation when the apparent resistivity is equal to the sea water resistivity is discussed in detail in the theoretical deduction process) generated between the apparent resistivity curve fitted by the cubic curve and the sea water resistivity straight line are utilized, the frequency and the attenuation coefficient corresponding to each intersection point are utilized to calculate the sea water depth, on one hand, the mean value reduction error can be calculated, on the other hand, the obviously inconsistent value can be removed, the mean value is calculated by utilizing the rest value, and the accuracy is improved.
In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart of a seawater depth detection method based on an electromagnetic field according to an embodiment of the present application.
Fig. 2 is a schematic diagram of a sea water-seabed medium.
Fig. 3 is a schematic view of the apparent resistivity curve of the observation point in example 1.
Fig. 4 is a schematic diagram of the sea resistivity line versus apparent resistivity curve in example 1.
Fig. 5 is a partial enlarged view of the sea resistivity straight line versus apparent resistivity curve in example 1.
Fig. 6 is a schematic view of the apparent resistivity curve of the observation point in example 2.
Fig. 7 is a schematic diagram of the sea resistivity line versus apparent resistivity curve in example 2.
Fig. 8 is a partial enlarged view of the sea resistivity straight line versus apparent resistivity curve in example 2.
Fig. 9 is a schematic view of the apparent resistivity curve of the observation point in example 3.
Fig. 10 is a schematic diagram of the sea resistivity line versus apparent resistivity curve in example 3.
Fig. 11 is a partial enlarged view of the sea resistivity straight line versus apparent resistivity curve in example 3.
Fig. 12 is a schematic view of the apparent resistivity curve of the observation point in example 4.
Fig. 13 is a schematic diagram of the sea resistivity line versus apparent resistivity curve in example 4.
Fig. 14 is a partial enlarged view of the sea resistivity straight line versus apparent resistivity curve in example 4.
Detailed Description
The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.
Referring to fig. 1, fig. 1 is a flowchart of a seawater depth detection method based on an electromagnetic field according to an embodiment of the present application. In this embodiment, the electromagnetic field-based sea water depth detection method is applied to an electronic device (such as a server or a terminal), and the method may include step S10, step S20, step S30, and step S40.
First, the electronic device may run step S10.
Step S10: an electric field and a magnetic field formed at an observation point of a remote zone by a natural source or an artificial field source are obtained.
In the present embodiment, the electronic apparatus can acquire an electric field and a magnetic field (electric field signal and magnetic field signal) formed by a natural source or an artificial field source at the observation point of the far zone. Natural sources: under the action of thunder and lightning phenomenon and solar wind, a global natural alternating electromagnetic field is distributed in the earth, the frequency range is wide, and plane waves can be regarded as incidence when the electromagnetic field reaches the earth. The artificial field source remote region can be defined by referring to a controllable source audio magnetotelluric sounding method: vertical area: the equatorial region of the power supply dipole, r >4 delta, is the far region; coaxial region: the axial region of the feed dipole, r >5 delta, is the far region. Where r is the distance from the observation point to the power supply dipole, delta is the skin depth,Ρ is the resistivity and f is the frequency.
After the electric field and the magnetic field are obtained, the electronic device may run step S20.
Step S20: based on the electric field and the magnetic field, the apparent resistivity of the observation point is determined.
In this embodiment, the electronic device may convert the electric field and the magnetic field (electric field signal and magnetic field signal) at the observation point into the corresponding apparent resistivity.
Since all macroscopic electromagnetic phenomena satisfy the Maxwell's equation set, consisting of faraday's law, ampere's law, coulomb's law and magnetic flux continuity principle, the differential form is:
Wherein, Is Hamiltonian, is/>, in rectangular coordinate systemE is the electric field strength, B is the magnetic induction strength, D is the electric displacement, H is the magnetic field strength, and ρ is the free charge density.
The three constitutive relations are:
D＝εE， (5)
B＝μH， (6)
J＝σE， (7)
Where ε is the dielectric constant, μ is the magnetic permeability, and σ is the electrical conductivity.
The electromagnetic field can be converted into a combination of a series of harmonic fields in a time domain through Fourier transformation, and the time harmonic factor is e -iωt (or e iωt), so that the electric field strength and the magnetic field strength can be respectively expressed as:
E＝E0e-iωt， (8)
H＝H0e-iωt， (9)
The Maxwell equation set for the harmonic field is then:
The incident electromagnetic field formed by the remote area of the natural source or the artificial field source can be approximately plane wave vertical incidence, and then the wave impedance of the electromagnetic field at the observation point is as follows:
Wherein E x is the electric field horizontal component in the x direction; e y is the electric field horizontal component in the y direction; h x is the magnetic field horizontal component in the x direction; h y is the magnetic field horizontal component in the y-direction.
The apparent resistivity at the observation point is:
Where ρ s is the apparent resistivity, ω is the angular frequency, ω=2pi f, f is the frequency, μ is the permeability, and Z obs is the wave impedance at the observation point, i.e., Z in the foregoing equation (14).
For a seawater-subsea two-layer medium (as shown in fig. 2), the impedance value at the surface of the second layer seawater medium is therefore:
wherein Z 2 (0) is the ground wave impedance, Is the attenuation factor, ω is the angular frequency, ε 1 is the dielectric constant of the first layer medium (i.e. sea water), ε 2 is the dielectric constant of the second layer medium (i.e. sea floor), μ is the magnetic permeability of the medium, μ in k 1 is the magnetic permeability of the first layer medium, μ in k 2 is the magnetic permeability of the second layer medium, μ is not distinguished here because μ variation is very small (the influence on the calculation result is very small), μ is used uniformly, default is vacuum magnetic permeability μ 0,σ1 is the first layer medium conductivity, h 1 is the thickness of the first layer medium, σ 2 is the second layer medium conductivity, and i is the imaginary unit.
Order the
Analytical formulae show that when cos2α=0, i.e.When the method is used, the following steps are included:
A1＝-B2， (22)
A2＝-B1， (23)
Then there are:
I.e. the modes of the two complex numbers are equal: |a|= |b|.
At this time, the apparent resistivity of the observation point is equal to the resistivity of seawater, namely:
ρs＝|Z2(0)|2/(ωμ)＝ρw， (25)
wherein ρ w is the sea water resistivity at the observation point.
The incident electromagnetic field formed by the natural source or artificial field source far zone can be approximately plane wave vertical incidence, in the marine electromagnetic environment, the seawater is a medium conductor, the conductivity distribution is generally between 1 and 5S/m (the seawater resistivity is generally between 0.2 and 1.0 Ω & m), the permeability is generally considered as permeability mu 0 in vacuum, the relative dielectric constant is about 80, at this time ωs is less than 1, the displacement current is negligible, i.e. iωε in the above formulas is negligible. Then, the sea water depth can be obtained from the apparent resistivity curve when the sea water conductivity (inverse relation to sea water resistivity, known sea water conductivity, i.e., known sea water resistivity) is known.
From the theory above, it is known that when apparent resistivity is equal to sea water resistivity, there are Taking the first 3 equivalent points from low frequency to high frequency,/>The method comprises the following steps:
In order to realize the detection of the sea water depth, the converted apparent resistivity needs to be fitted to obtain an apparent resistivity curve. Accordingly, the electronic device may run step S30. The apparent resistivity obtained at the observation point is the apparent resistivity of many frequencies containing the sea water and the submarine medium information, so as to be used for fitting the apparent resistivity curve.
Step S30: and fitting a visual resistivity curve based on the visual resistivity of the observation point.
In this embodiment, the electronic device may perform preliminary data processing on the apparent resistivity, and fit the apparent resistivity with a cubic curve to obtain a curve ρ s of the apparent resistivity.
For example, in example 1, a sea water-seabed medium model was constructed, the sea water resistivity was 1 Ω·m, the depth was 100m, the seabed medium resistivity was 10 Ω·m, and the sea surface observation point apparent resistivity curve (obtained by fitting the actual observation apparent resistivity curve in actual application, the apparent resistivity data used here as an example was directly calculated from the model constructed by way of example, and cannot be regarded as limiting the present application) was shown in fig. 3.
After obtaining the apparent resistivity curve, the electronic device may run step S40.
Step S40: and acquiring the seawater resistivity of the observation point, and determining the seawater depth of the observation point based on the seawater resistivity and the apparent resistivity curve.
First, description will be made taking a case of a seawater-seabed medium (the seabed medium is regarded as one layer as a whole) as an example:
The electronic device may acquire the sea water resistivity at the observation point (it is to be noted that, if the sea water resistivity is assumed to be unchanged, the acquired sea water resistivity is the resistivity value of any place of the sea water, and if the sea water resistivity is assumed to be changed, the acquired sea water resistivity is the longitudinal resistivity within the sea water depth), and determine the sea water resistivity straight line based on the sea water resistivity. Since conductivity and resistivity are reciprocal, sea water resistivity ρ w can also be calculated by substituting the obtained sea water conductivity σ w (non-zero) into the following formula:
Thus, the electronic device can obtain the seawater resistivity ρ w straight line.
For example, example 1, seawater resistivity ρ w was plotted together into a apparent resistivity ρ s curve, as shown in fig. 4.
Further, the electronic device can determine the first three intersection points of the apparent resistivity ρ s curve of the observation point and the seawater resistivity straight line, and the intersection points can be judged by adopting the following formula:
(ρs(fn-1)-ρw(fn-1))(ρs(fn)-ρw(fn))<0, (28)
After determining the first three intersections (as shown in fig. 5) of the apparent resistivity curve of the observation point and the seawater resistivity line in example 1, the electronic device may calculate the seawater depth of the observation point based on the frequency at least one intersection and the corresponding attenuation coefficient.
For example, the electronic device may determine the frequency f 1、f2、f3 and the corresponding attenuation coefficient α 1、α2、α3 for the first three intersections.
Substituting at least one set of f 1 and α 1、f2 and α 2、f3 and α 3 into the formula to calculate the sea water depth:
Wherein h w is the sea water depth, alpha i is the attenuation coefficient corresponding to the ith intersection point, f i is the frequency corresponding to the ith intersection point, ρ w is the sea water resistivity, and μ 0 is the vacuum magnetic permeability.
For example, the electronics can calculate the sea water depth by substituting f 1 and α 1、d2 and α 2、f3 and α 3 into equation (29), respectively, to calculate three sea water depths h w1、hw2、hw3 (theoretically, 3 sea water depth values should be the same when there is no error and all data are accurate). The electronic device may then determine that: if the difference between every two of the h w1、hw2、hw3 is not more than the set proportion (for example, not more than 2%), the average value of the h w1、hw2、hw3 is calculated as the sea water depth. If the difference between every two of the h w1、hw2、hw3 is larger than the set proportion, the electronic equipment can reject one seawater depth value with the largest difference with the other two, and the average value between the two seawater depth values is calculated as the seawater depth.
Example 1 by adopting the electromagnetic field-based seawater depth detection method of the present solution, frequencies corresponding to the first 3 intersecting points from low frequency to high frequency are found out in sequence, respectively: f 1＝15.64、f2＝140.60、f3 =390.80, and the sea water depths are calculated according to formula (29):
it can be seen that by adopting the seawater depth detection method in example 1, the seawater depth can be better calculated according to the first 3 frequency points, and the relative error of the calculated seawater depth in the example is less than 0.05%.
In addition, for the case of sea-seabed medium (seabed medium is considered as a hierarchy as a whole), further provided is an example 2: a sea water-seabed two-layer medium model is established, the sea water resistivity is 1 Ω·m, the depth is 1000m, the seabed medium resistivity is 10 Ω·m, the sea surface observation point apparent resistivity curve (obtained by fitting the actual observation apparent resistivity curve in actual application, the apparent resistivity data used herein is directly calculated by the model constructed by way of example and cannot be regarded as limiting the application) is shown in fig. 6. The seawater resistivity ρ w is then plotted along a line into a apparent resistivity ρ s curve, as shown in fig. 7, with a partial enlargement of the seawater resistivity line and apparent resistivity curve, as shown in fig. 8.
Example 2 the electromagnetic field-based sea water depth detection method of the present embodiment is also adopted, and frequencies corresponding to the first 3 intersecting points from low frequency to high frequency are found in sequence, respectively: f 1＝0.1562、f2＝1.406、f3 = 3.908, and the sea water depths are calculated according to formula (29):
it can be seen that by adopting the seawater depth detection method in example 2, the seawater depth can be better calculated according to the first 3 frequency points, and the relative error of the calculated seawater depth in the example is less than 0.03%.
Next, description will be made taking a case where the submarine medium in the seawater-submarine medium includes a plurality of sub-levels as an example:
When the sub-level medium is a medium containing a plurality of sub-levels, the equation (29) is strictly derived when the sea-bottom two-level medium (the bottom is regarded as a medium containing only one sub-level) is applied, because the plurality of sub-level mediums may be approximated as one uniform half-space with equal longitudinal resistivity (i.e., equal longitudinal conductivity), but is still applied to the case of the sub-bottom multi-level medium (i.e., the medium containing a plurality of sub-levels is regarded as one uniform half-space with equal longitudinal resistivity, so that the equation (29) is still applied).
For the case of sea-ocean bottom media (ocean bottom media is media comprising multiple sub-levels, but the ocean bottom media as a whole is considered to be one uniform half-space with equal longitudinal resistivity), an example 3 is provided: a sea-water-seabed three-layer medium model is established (i.e. the seabed medium is a medium comprising two sub-layers), sea resistivity is 1 Ω·m, the depth is 100m, the resistivity of the first layer in the seabed medium is 10 Ω·m, the depth is 500m, the resistivity of the second layer in the seabed medium is 20 Ω·m, and the sea observation point apparent resistivity curve (obtained by fitting the actual observation apparent resistivity curve in actual application, and the apparent resistivity data used herein is directly calculated from the model constructed by way of example and cannot be regarded as limiting the application) is shown in fig. 9. The seawater resistivity ρ w is then plotted along a line into a apparent resistivity ρ s curve, as shown in fig. 10, with a partial enlargement of the seawater resistivity line and apparent resistivity curve, as shown in fig. 11.
Example 3 the electromagnetic field-based sea water depth detection method of the present embodiment is also adopted, and frequencies corresponding to the first 3 intersecting points from low frequency to high frequency are found in sequence, respectively: f 1＝15.36、f2＝140.65、f3 = 390.55, and the sea water depths are calculated according to formula (29):
it can be seen that by adopting the seawater depth detection method in example 3, the seawater depth can be better calculated according to the first 3 frequency points, and the relative error of the calculated seawater depth in the example is less than 0.15%.
For the case of sea-ocean bottom media (ocean bottom media is media comprising multiple sub-levels, but the ocean bottom media as a whole is considered to be one uniform half-space with equal longitudinal resistivity), an example 4 is provided: a sea water-seabed four-layer medium model is established (i.e. the seabed medium is a medium comprising three sub-layers), the sea water resistivity is 1 Ω·m, the depth is 100m, the resistivity of the first layer in the seabed medium is 10 Ω·n, the depth is 1000m, the resistivity of the second layer in the seabed medium is 30 Ω·m, the depth is 500m, the resistivity of the third layer in the seabed medium is 50 Ω·m, and the sea surface observation point apparent resistivity curve (obtained by fitting the actual observation apparent resistivity curve in actual application, and apparent resistivity data used herein is directly calculated from the model constructed by way of example and cannot be regarded as limiting the application) is shown in fig. 12. The seawater resistivity ρ w is then plotted along a line into a apparent resistivity ρ s curve, as shown in fig. 13, with a partial enlargement of the seawater resistivity line and apparent resistivity curve, as shown in fig. 14.
Example 4 the electromagnetic field-based sea water depth detection method of the present embodiment is also adopted, and frequencies corresponding to the first 3 intersecting points from low frequency to high frequency are found in sequence, respectively: f 1＝15.67、f2＝140.65、f3 = 390.58, and the sea water depths are calculated according to formula (29):
It can be seen that by adopting the seawater depth detection method in example 4, the seawater depth can be better calculated according to the first 3 frequency points, and the relative error of the calculated seawater depth in the example is less than 0.15%.
Thus, by this scheme, sea water depth can be measured after sea water resistivity (or sea water conductivity) is known.
The embodiment of the application provides a storage medium which is installed in equipment and comprises a stored program, wherein the equipment where the storage medium is controlled to execute the seawater depth detection method based on the electromagnetic field when the program runs.
The embodiment of the application provides electronic equipment, which comprises a memory and a processor, wherein the memory is used for storing information comprising program instructions, and the processor is used for controlling execution of the program instructions, and the program instructions realize the steps of the electromagnetic field-based sea water depth detection method when loaded and executed by the processor.
In summary, the embodiment of the application provides a seawater depth detection method, a storage medium and an electronic device based on an electromagnetic field, which are implemented by firstly converting electromagnetic field signal series through electric field and magnetic field signals formed at observation points of a remote zone by a natural source or an artificial field source collected in the air or seawater to obtain a apparent resistivity curve of the observation points. And then carrying out theoretical deduction, and establishing a theoretical calculation formula for excavating the sea water depth and sea water conductivity information (basically, sea water depth and sea water resistivity) according to the apparent resistivity curve, so that after the sea water resistivity of the observation point is obtained, the sea water depth of the observation point can be determined based on the sea water resistivity and the apparent resistivity curve (combined with the theoretical calculation formula). Therefore, the detection efficiency of the sea water depth can be effectively improved, and the method can provide a more suitable detection means under various different conditions in an actual detection scene as an effective complementary method and means of the existing mainstream detection method.
When the theoretical calculation formula constructed by deduction is utilized to calculate the sea water depth, three intersection points (the relation when the apparent resistivity is equal to the sea water resistivity is discussed in detail in the theoretical deduction process) generated between the apparent resistivity curve fitted by the cubic curve and the sea water resistivity straight line are utilized, the frequency and the attenuation coefficient corresponding to each intersection point are utilized to calculate the sea water depth, on one hand, the mean value reduction error can be calculated, on the other hand, the obviously inconsistent value can be removed, the mean value is calculated by utilizing the rest value, and the accuracy is improved.
In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.
The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and variations will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. A seawater depth detection method based on an electromagnetic field, comprising:
Acquiring an electric field and a magnetic field formed by a natural source or an artificial field source at a remote area observation point;
Based on the electric field and the magnetic field, determining apparent resistivity of the observation point;
Fitting a visual resistivity curve based on the visual resistivity of the observation point;
And acquiring the seawater resistivity of the observation point, and determining the seawater depth of the observation point based on the seawater resistivity and the apparent resistivity curve.
2. The electromagnetic field-based seawater depth detection method of claim 1, wherein determining apparent resistivity of the observation point based on the electric field and the magnetic field comprises:
the incident electric field and magnetic field formed by the natural source or artificial field source in the far zone are similar to plane wave vertical incidence, and the wave impedance is as follows:
Wherein E x is the electric field horizontal component in the x direction; e y is the electric field horizontal component in the y direction; h x is the magnetic field horizontal component in the x direction; h y is the magnetic field horizontal component in the y-direction;
The apparent resistivity at the observation point is:
Where ρ s is apparent resistivity, ω is angular frequency, μ is permeability, and Z obs is wave impedance at the observation point.
3. The electromagnetic field based seawater depth detection method of claim 1, wherein fitting a apparent resistivity curve based on apparent resistivity of the observation point comprises:
and (5) performing primary data processing on the apparent resistivity, and fitting by adopting a cubic curve.
4. The electromagnetic field-based seawater depth detection method as recited in claim 3, wherein obtaining the seawater resistivity at the observation point, determining the seawater depth at the observation point based on the seawater resistivity and the apparent resistivity curve, comprises:
acquiring the seawater resistivity of the observation point, and determining a seawater resistivity straight line based on the seawater resistivity;
determining the first three intersection points of the apparent resistivity curve of the observation point and the seawater resistivity straight line;
and calculating the sea water depth of the observation point based on the frequency at the at least one intersection point and the corresponding attenuation coefficient.
5. The electromagnetic field based seawater depth detection method of claim 4, wherein calculating the seawater depth at the observation point based on the frequency at the at least one intersection point and the corresponding attenuation coefficient comprises:
Determining the frequency f 1、f2、f3 of the first three intersection points and the corresponding attenuation coefficient alpha 1、α2、α3;
Substituting at least one set of f 1 and α 1、f2 and α 2、f3 and α 3 into the formula to calculate the sea water depth:
Wherein h w is the sea water depth, alpha i is the attenuation coefficient corresponding to the ith intersection point, f i is the frequency corresponding to the ith intersection point, ρ w is the sea water resistivity, and μ 0 is the vacuum magnetic permeability.
6. The electromagnetic field based seawater depth detection method of claim 5, wherein substituting at least one set of f 1 and α 1、f2 and α 2、f3 and α 3 into the formula to calculate the seawater depth comprises:
F 1, alpha 1、f2, alpha 2、f3 and alpha 3 are respectively substituted into a formula to calculate the sea water depth, and three sea water depths h w1、hw2、hw3 are calculated;
If the difference between every two of the h w1、hw2、hw3 does not exceed the set threshold value, calculating the average value of the h w1、hw2、hw3 as the sea water depth;
If the difference between every two of the h w1、hw2、hw3 is larger than the set threshold value, removing one seawater depth value with the largest difference with the other two seawater depth values, and calculating the average value between the two seawater depth values as the seawater depth.
7. The electromagnetic field-based seawater depth detection method as claimed in claim 5, wherein the observation point is provided with a seawater-seabed medium, the detected seawater depth is the thickness of the seawater of the first medium layer, and the attenuation coefficient alpha i is as follows:
Where ω is angular frequency, μ is permeability of seawater, σ 1 is first layer medium conductivity, and h 1 is first layer medium thickness.
8. The electromagnetic field based seawater depth detection method of claim 7, wherein the subsea medium is one or more layers.
9. A storage medium, characterized in that the storage medium is installed in a device, comprising a stored program, wherein the program, when run, controls the device in which the storage medium is located to perform the electromagnetic field based sea water depth detection method according to any one of claims 1 to 8.
10. An electronic device comprising a memory for storing information including program instructions and a processor for controlling execution of the program instructions, characterized by: the program instructions, when loaded and executed by a processor, carry out the steps of the electromagnetic field based sea water depth detection method according to any one of claims 1 to 8.
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