Airborne magnetic interference suppression method, device and equipment based on double-machine multi-magnetic sensor

Abstract

The application discloses an aviation magnetic interference suppression method, device and equipment based on double-machine multi-magnetic sensors, wherein two magnetic sensors are arranged on two magnetic exploration airplanes respectively, the two magnetic exploration airplanes are located at the same height, and the height difference between any one of the magnetic exploration airplanes and a position of a detection target is h; the two magnetic exploration airplanes are apart from each other by L; the detection distances of the two magnetic exploration airplanes are both R; it can be guaranteed that the two magnetic exploration airplanes cannot measure the target signal at the same time, so that only one of the common-mode magnetic signals of the magnetic exploration airplanes contains the target signal and the diurnal magnetic interference signal, and the common-mode signal of the other magnetic exploration airplane contains only the diurnal magnetic interference signal; the target signal after the diurnal magnetic interference signal is removed can be obtained by subtracting the common-mode signals of the two magnetic exploration airplanes; and the diurnal magnetic interference signal can be better suppressed through the method, so that the accuracy of the target signal is improved.

Description

Technical Field

[0001] This invention relates to the field of airborne magnetic detection technology, and in particular to an airborne magnetic interference suppression method, apparatus, and equipment based on dual-aircraft multi-magnetic sensors. Background Technology

[0002] Airborne magnetic surveying (AMS) measures the Earth's magnetic field in space using high-sensitivity magnetic sensors mounted on an airborne platform, and then extracts ferromagnetic target signals under complex magnetic background noise using signal processing techniques. It features passive and covert detection capabilities and is not limited by time or weather, thus it is widely used in airborne geophysical exploration, military defense, and other fields. In AMS, with the continuous development of magnetic sensor technology, the sensitivity of magnetic sensors has reached the pT level, and the determining factor for detection quality is now the suppression level of magnetic interference from the platform itself and environmental magnetic interference such as diurnal variations.

[0003] In airborne magnetic surveying, research on diurnal magnetic interference is limited, especially high-precision real-time processing methods. A common approach is to set up ground-based diurnal magnetic stations and subtract the ground-based station data from the airborne magnetic survey data. However, it is generally believed that the diurnal magnetic field exhibits a certain correlation within a 300km range. Beyond this range, the correlation between the diurnal magnetic interference measured by the airborne magnetic sensor and the magnetic interference measured by the ground reference station drops sharply, rendering the ground reference station data unreliable. Furthermore, the ground reference station data is easily affected by ground-based anthropogenic magnetic interference. Therefore, the target signal extracted using the above methods is not accurate enough. Summary of the Invention

[0004] This invention provides a method, apparatus, and device for suppressing airborne magnetic interference based on dual-machine multi-magnetic sensors, which can effectively eliminate diurnal magnetic interference and improve the accuracy of target signal extraction.

[0005] An embodiment of the present invention provides an airborne magnetic interference suppression method based on dual-aircraft multi-magnetic sensors, comprising: acquiring a first magnetic field signal measured by a first magnetic sensor, a second magnetic field signal measured by a second magnetic sensor, a third magnetic field signal measured by a third magnetic sensor, and a fourth magnetic field signal measured by a fourth magnetic sensor; wherein the first magnetic field sensor and the second magnetic sensor are mounted on a first magnetic probe aircraft; the third magnetic field sensor and the fourth magnetic sensor are mounted on a second magnetic probe aircraft; the first magnetic probe aircraft and the second magnetic probe aircraft are at the same altitude, and the altitude difference between any one magnetic probe aircraft and the location of the detection target is h; the first magnetic probe aircraft and the second magnetic probe aircraft are laterally separated by L; the detection distance of the first magnetic probe aircraft and the second magnetic probe aircraft is R.

[0006] The first magnetic field signal, the second magnetic field signal, the third magnetic field signal, and the fourth magnetic field signal are respectively preprocessed to obtain the first processed signal, the second processed signal, the third processed signal, and the fourth processed signal; wherein, the signal preprocessing includes: platform magnetic interference compensation and filtering;

[0007] The common-mode magnetic signal of the first magnetic probe aircraft is extracted based on the first processed signal and the second processed signal to obtain the first common-mode magnetic signal;

[0008] The common-mode magnetic signal of the second magnetic probe aircraft is extracted based on the second processed signal and the third processed signal to obtain the second common-mode magnetic signal;

[0009] The target signal corresponding to the detection target is obtained by subtracting the first common-mode magnetic signal and the second common-mode magnetic signal.

[0010] Furthermore, the first magnetic sensor and the second magnetic sensor are respectively disposed at the wingtips of the left and right wings of the first magnetic probe aircraft; the third magnetic sensor and the fourth magnetic sensor are respectively disposed at the wingtips of the left and right wings of the second magnetic probe aircraft.

[0011] Furthermore, the first magnetic sensor and the second magnetic sensor are disposed on the same wing of the first magnetic probe aircraft, and the first magnetic sensor and the second magnetic sensor are separated by a first preset distance; the third magnetic sensor and the fourth magnetic sensor are disposed on the same wing of the second magnetic probe aircraft, and the third magnetic sensor and the fourth magnetic sensor are separated by a second preset distance.

[0012] Further, based on the first processed signal and the second processed signal, the common-mode magnetic signal of the first magnetic probe aircraft is extracted to obtain the first common-mode magnetic signal, including:

[0013] The first common-mode magnetic signal is extracted using the following formula:

[0014]

[0015] Among them, B common1 B is the first common-mode magnetic signal; fp1 B is the sum of the first processed signal and the second processed signal; fm1 H is the difference between the first processed signal and the second processed signal; H is the linear relationship coefficient of aircraft magnetic interference in the first processed signal and the second processed signal.

[0016] Furthermore, the common-mode magnetic signal of the second magnetic probe aircraft is extracted based on the second processed signal and the third processed signal to obtain the second common-mode magnetic signal;

[0017] The second common-mode magnetic signal is extracted using the following formula:

[0018]

[0019] Among them, B common2 B is the second common-mode magnetic signal. fp2 B is the sum of the third processed signal and the fourth processed signal. fm2 is the difference between the third and fourth processed signals; K is the linear relationship coefficient between the aircraft magnetic interference in the third and fourth processed signals.

[0020] Based on the above method embodiments, the present invention provides corresponding apparatus embodiments;

[0021] An embodiment of the present invention provides an airborne magnetic interference suppression device based on dual-machine multi-magnetic sensors, comprising: a signal receiving module, a signal preprocessing module, a first common-mode magnetic signal extraction module, a second common-mode magnetic signal extraction module, and a target signal extraction module;

[0022] The signal receiving module is used to acquire a first magnetic field signal measured by a first magnetic sensor, a second magnetic field signal measured by a second magnetic sensor, a third magnetic field signal measured by a third magnetic sensor, and a fourth magnetic field signal measured by a fourth magnetic sensor; wherein the first magnetic field sensor and the second magnetic sensor are mounted on a first magnetic probe aircraft; the third magnetic field sensor and the fourth magnetic sensor are mounted on a second magnetic probe aircraft; the first magnetic probe aircraft and the second magnetic probe aircraft are at the same altitude, and the altitude difference between either magnetic probe aircraft and the location of the detection target is h; the first magnetic probe aircraft and the second magnetic probe aircraft are spaced L apart laterally; the detection distance of both the first magnetic probe aircraft and the second magnetic probe aircraft is R;

[0023] The signal preprocessing module is used to preprocess the first magnetic field signal, the second magnetic field signal, the third magnetic field signal, and the fourth magnetic field signal respectively to obtain the first processed signal, the second processed signal, the third processed signal, and the fourth processed signal; wherein, the signal preprocessing includes: platform magnetic interference compensation and filtering;

[0024] The first common-mode magnetic signal extraction module is used to extract the common-mode magnetic signal of the first magnetic probe aircraft based on the first processed signal and the second processed signal to obtain the first common-mode magnetic signal;

[0025] The second common-mode magnetic signal extraction module is used to extract the common-mode magnetic signal of the second magnetic probe aircraft based on the second processed signal and the third processed signal, and obtain the second common-mode magnetic signal.

[0026] The target signal extraction module is used to subtract the first common-mode magnetic signal and the second common-mode magnetic signal to obtain the target signal corresponding to the detected target.

[0027] Furthermore, the first common-mode magnetic signal extraction module extracts the common-mode magnetic signal of the first magnetic probe aircraft based on the first processed signal and the second processed signal to obtain the first common-mode magnetic signal, including:

[0028] The first common-mode magnetic signal is extracted using the following formula:

[0029]

[0030] Among them, B common1 B is the first common-mode magnetic signal; fp1 B is the sum of the first processed signal and the second processed signal; fm1 H is the difference between the first processed signal and the second processed signal; H is the linear relationship coefficient of aircraft magnetic interference in the first processed signal and the second processed signal.

[0031] Furthermore, the second common-mode magnetic signal extraction module extracts the common-mode magnetic signal of the second magnetic probe aircraft based on the second processed signal and the third processed signal to obtain the second common-mode magnetic signal;

[0032] The second common-mode magnetic signal is extracted using the following formula:

[0033]

[0034] Among them, B common2 B is the second common-mode magnetic signal. fp2 B is the sum of the third processed signal and the fourth processed signal. fm2 is the difference between the third and fourth processed signals; K is the linear relationship coefficient between the aircraft magnetic interference in the third and fourth processed signals.

[0035] Based on the above method embodiments, the present invention provides corresponding device embodiments;

[0036] One embodiment of the present invention provides a device comprising: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the airborne magnetic interference suppression method based on dual-machine multi-magnetic sensors as described in any one of the present invention.

[0037] The following benefits can be obtained by implementing the present invention:

[0038] An embodiment of the present invention provides an airborne magnetic interference suppression method, apparatus and equipment based on dual-aircraft multi-magnetic sensors. The method involves deploying two magnetic sensors on two magnetic probe aircraft, with the two magnetic probe aircraft at the same altitude, and the altitude difference between any one magnetic probe aircraft and the location of the target being detected being h; the two magnetic probe aircraft are spaced L apart to the left and right; and the detection distance of both magnetic probe aircraft is R. This ensures that the two magnetic anomaly aircraft cannot simultaneously measure the target signal. Consequently, only one aircraft's common-mode magnetic signal contains both the target signal and diurnal magnetic interference, while the other aircraft's common-mode signal contains only the diurnal magnetic interference. Subtracting the common-mode signals from the two aircraft removes the diurnal magnetic interference, thus extracting the target signal. The target signal extracted in this way is unaffected by ground-based human magnetic interference, and the strong correlation between the diurnal magnetic interference measured by the two aircraft's airborne magnetic sensors further enhances the suppression of diurnal magnetic interference and improves the accuracy of the target signal. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating an airborne magnetic interference suppression method according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram of a first magnetic field signal and a second magnetic field signal provided in an embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of the third and fourth magnetic field signals provided in an embodiment of the present invention.

[0042] Figure 4 This is a schematic diagram of a first common-mode magnetic signal provided in an embodiment of the present invention.

[0043] Figure 5 This is a schematic diagram of a second common-mode magnetic signal provided in an embodiment of the present invention.

[0044] Figure 6 This is a schematic diagram of a target signal provided in an embodiment of the present invention.

[0045] Figure 7 This is a schematic diagram of the magnetic sensor placement position according to an embodiment of the present invention.

[0046] Figure 8 This is a schematic diagram of another installation position of the magnetic sensor provided in one embodiment of the present invention.

[0047] Figure 9 This is a schematic diagram illustrating the principle of target signal extraction according to an embodiment of the present invention.

[0048] Figure 10 This is a schematic diagram of the structure of an airborne magnetic interference suppression device provided in an embodiment of the present invention. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] First, it should be noted that the airborne magnetic interference suppression method based on dual-machine multi-magnetic sensors described in this invention is applicable to operation within a host computer.

[0051] like Figure 1 As shown, one embodiment of the present invention provides an airborne magnetic interference suppression method based on dual-aircraft multi-magnetic sensors, which includes at least the following steps:

[0052] Step S101: Acquire a first magnetic field signal measured by a first magnetic sensor, a second magnetic field signal measured by a second magnetic sensor, a third magnetic field signal measured by a third magnetic sensor, and a fourth magnetic field signal measured by a fourth magnetic sensor; wherein, the first magnetic field sensor and the second magnetic sensor are mounted on a first magnetic probe aircraft; the third magnetic field sensor and the fourth magnetic sensor are mounted on a second magnetic probe aircraft; the first magnetic probe aircraft and the second magnetic probe aircraft are at the same altitude, and the altitude difference between either magnetic probe aircraft and the location of the detection target is h; the first magnetic probe aircraft and the second magnetic probe aircraft are laterally separated by L; the detection distance of the first magnetic probe aircraft and the second magnetic probe aircraft is R.

[0053] Step S102: Perform signal preprocessing on the first magnetic field signal, the second magnetic field signal, the third magnetic field signal, and the fourth magnetic field signal respectively to obtain the first processed signal, the second processed signal, the third processed signal, and the fourth processed signal; wherein, the signal preprocessing includes: platform magnetic interference compensation and filtering.

[0054] Step S103: Extract the common-mode magnetic signal of the first magnetic probe aircraft based on the first processed signal and the second processed signal to obtain the first common-mode magnetic signal.

[0055] Step S104: Extract the common-mode magnetic signal of the second magnetic probe aircraft based on the second processed signal and the third processed signal to obtain the second common-mode magnetic signal.

[0056] Step S105: Subtract the first common-mode magnetic signal and the second common-mode magnetic signal to obtain the target signal corresponding to the detected target.

[0057] For step S101: In an optional embodiment, the first magnetic sensor and the second magnetic sensor are respectively disposed at the wingtips of the left and right wings of the first magnetic probe aircraft; the third magnetic sensor and the fourth magnetic sensor are respectively disposed at the wingtips of the left and right wings of the second magnetic probe aircraft.

[0058] In another optional embodiment, the first magnetic sensor and the second magnetic sensor are disposed on the same wing of the first magnetic probe aircraft, and the first magnetic sensor and the second magnetic sensor are separated by a first preset distance; the third magnetic sensor and the fourth magnetic sensor are disposed on the same wing of the second magnetic probe aircraft, and the third magnetic sensor and the fourth magnetic sensor are separated by a second preset distance.

[0059] Specifically, firstly, two highly consistent magnetic sensors are deployed on each of the two magnetic prospecting aircraft. There are two methods for deploying these sensors. The first method is to deploy a high-sensitivity magnetic sensor on each wingtip of the magnetic prospecting aircraft, such as... Figure 7 As shown, the first magnetic probe aircraft 1 has a first magnetic sensor 11 installed on its left wing and a second magnetic sensor 12 installed on its right wing; the second magnetic probe aircraft 2 has a third magnetic sensor 21 installed on its left wing and a fourth magnetic sensor 22 installed on its right wing.

[0060] The second method involves simultaneously deploying two highly sensitive magnetic sensors on one side of the magnetic probe aircraft. For example... Figure 8 As shown, the first magnetic probe aircraft 1 has a first magnetic sensor 11 installed at the wingtip of its left wing, and a second magnetic sensor 12 installed at a certain distance from the first magnetic sensor, ensuring that the magnetic interference measured by the two magnetic sensors has a certain difference. The second magnetic probe aircraft 2 has a third magnetic sensor 21 installed at the wingtip of its left wing, and a fourth magnetic sensor 22 installed at a certain distance from the third magnetic sensor.

[0061] To reduce interference, when using any of the above methods, the two magnetic sensors should be placed as far away from the machine body as possible, and the area around the placement location should be cleaned of magnetic interference.

[0062] After installation, the magnetic field data measured by the magnetic sensors on the two magnetic probe aircraft needs to be synchronously transmitted to a host computer to ensure that the data measured by the four magnetic sensors on the two aircraft are synchronized.

[0063] For step S102, assuming the first magnetic field signal, the second magnetic field signal, the third magnetic field signal, and the fourth magnetic field signal are respectively: B mr11 B mr12 B mr21 B mr22 ; Schematic diagrams of the first and second magnetic field signals are shown below. Figure 2 As shown ( Figure 2 In the diagram, the signal collected by the first magnetic sensor is the first magnetic field signal, the signal collected by the second magnetic sensor is the second magnetic field signal, and the schematic diagrams of the third and fourth magnetic field signals are shown below. Figure 3 As shown ( Figure 3 In the process, the signal collected by the first magnetic sensor is the third magnetic field signal, and the signal collected by the second magnetic sensor is the fourth magnetic field signal.

[0064] The data measured by the four magnetic sensors first need to be compensated using the traditional Platform Magnetic Interference (TLG) method. This method can remove magnetic interference caused by the platform's mechanical magnetic interference (as a whole), static current, and geomagnetic gradient. The compensated magnetic field data is shown in the formula below:

[0065]

[0066] In the above formula, B m11 The signal is the compensated signal of the first magnetic field; a i ,i=1,2,…,19 are the 19 coefficients to be determined in the existing platform magnetic interference compensation method, f i 1 The terms i = 1, 2, 3, ..., 19 are the corresponding 19 basis functions, which are expressed as:

[0067] f1=cosα X f2=cosα Y f3=cosα Z ,

[0068] f4 = T g cosα X Cosα X f5 = T g cosα X cosα Y f6=T g cosα X cosα Z ,

[0069] f7 = T g cosα Y cosα Y f8=T g cosα Y cosα Z ,

[0070] f9 = T g cosα X (cosα X )′, 10 =Tg cosα X (cosα Y )′,f 11 =T g cosα X (cosα Z )′,

[0071] f 12 =T g cosα Y (cosα X )′,f 13 =T g cosα Y (cosα Y )′,f 14 =T g cosα Y (cosα Z )′,

[0072] f 15 =T g cosα Z (cosα X )′,f 16 =T g cosα Z (cosα Y )′,

[0073] f 17 =lat,f 18 =long,f 19 =alt;

[0074] In the above formula, T g To represent the Earth's magnetic field, the magnetic field data measured by a scalar magnetic sensor can be obtained by passing it through a low-pass filter. cosα X ,cosα Y ,cosα Z The direction cosine of the Earth's magnetic field is obtained by measuring the fluxgate magnetometer on an aircraft. (cosα) X )′,(cosα Y )′,(cosα Z )′ represent cosα respectively X ,cosα Y ,cosα Z The derivatives of , lat, long, and alt represent the aircraft's position information, namely latitude, longitude, and altitude.

[0075] Similarly:

[0076]

[0077]

[0078] B m12 B is the compensated signal of the second magnetic field signal. m21 B is the compensated signal of the third magnetic field signal. m22 This is the compensated signal of the fourth magnetic field.

[0079] In airborne magnetic detection, the magnetic interference generated by the ferromagnetic target being detected is typically within a narrow frequency band. To reduce unnecessary problems caused by out-of-band noise, a bandpass filter is usually applied before target detection. The bandwidth of the filter is determined based on the speed of the magnetic sensor and the distance between the sensor and the target during detection. Let this bandpass filter be denoted by `filter`, then the data from the four magnetic sensors after filtering are expressed as follows:

[0080] B f11 =filter(B m11 (5)

[0081] B f12 =filter(B m12 (6)

[0082] B f21 =filter(B m21 (7)

[0083] B f22 =filter(B m22 (8)

[0084] In the above formula, B f11 The first processed signal mentioned above; B f12 The second processed signal mentioned above; B f21 The third processed signal mentioned above; B f22 This is the fourth processed signal mentioned above.

[0085] For step S103, in a preferred embodiment, extracting the common-mode magnetic signal of the first magnetic probe aircraft based on the first processed signal and the second processed signal to obtain the first common-mode magnetic signal includes:

[0086] The first common-mode magnetic signal is extracted using the following formula:

[0087]

[0088] Among them, B common1 B is the first common-mode magnetic signal; fp1 B is the sum of the first processed signal and the second processed signal; fm1H is the difference between the first processed signal and the second processed signal; H is the linear relationship coefficient of aircraft magnetic interference in the first processed signal and the second processed signal.

[0089] Specifically, since the first magnetic probe aircraft and the second magnetic probe aircraft are at the same altitude, and the altitude difference between any magnetic probe aircraft and the location of the detection target is h; the first magnetic probe aircraft and the second magnetic probe aircraft are laterally separated by L; and the detection distance of the first magnetic probe aircraft and the second magnetic probe aircraft is R. At this point, it can be ensured that the two magnetic probe aircraft cannot simultaneously measure the target signal; therefore, only the magnetic sensor measurement data of one magnetic probe aircraft contains the target magnetic field signal. Here, we take the magnetic field data measured by the first magnetic probe aircraft containing the target magnetic field signal as an example.

[0090] After the above preprocessing, the first processed signal, the second processed signal, the third processed signal, and the fourth processed signal can be represented by the following formula:

[0091] B f11 =B common1 +B airplane11 +B n1 (9)

[0092] B f12 =B common1 +B airplane12 +B n2 (10)

[0093] B f21 =B common2 +B airplane21 +B n3 (11)

[0094] B f22 =B common2 +B airplane22 +B n4 (12)

[0095] In the formula, B common1 The first common-mode magnetic signal mentioned above includes environmental magnetic interference such as diurnal variations and the target magnetic field signal, B. airplane11 B represents the residual magnetic interference of the aircraft measured by the first magnetic sensor. n1 For Gaussian white noise, B airplane12 B represents the residual magnetic interference of the aircraft measured by the second magnetic sensor. n2 Gaussian white noise; B common2 The second common-mode magnetic signal contains only environmental magnetic interference such as diurnal variations and does not contain the target signal. (B) airplane21 B represents the residual magnetic interference of the aircraft measured by the third magnetic sensor. n3 Gaussian white noise; B airplane22B represents the residual magnetic interference of the aircraft measured by the fourth magnetic sensor. n4 It is Gaussian white noise.

[0096] Since the first common-mode magnetic signal contains diurnal magnetic interference and the target signal, while the second common-mode magnetic signal only contains diurnal magnetic interference, then...

[0097] B common1 =B dirunal +B target (13)

[0098] B common2 =B dirunal (14)

[0099] In the formula B dirunal For diurnal magnetic interference, B target For target signal.

[0100] Considering that the above relationship is a linear time-invariant system in a short time interval, then we have

[0101] B airplane11 =H·B airplane12 (15)

[0102] B airplane21 =K·B airplane22 (16)

[0103] In the formula, H is the linear relationship coefficient of aircraft magnetic interference in the first and second processed signals to be determined; K is the linear relationship coefficient of aircraft magnetic interference in the third and fourth processed signals to be determined.

[0104] Therefore, formula (9)B f11 =B common1 +B airplane11 +B n1 (9. Formulas (10), (11), and (12) can be expressed as:

[0105] B f11 =B common1 +H·B airplane12 +B n1 (17)

[0106] B f12 =B common1 +B airplane12 +B n2 (18)

[0107] B f21 =B common2 +K·B airplane22 +B n3 (19)

[0108] B f22 =B common2 +B airplane22 +B n4 (20)

[0109] Adding formula (17) to formula (18) yields:

[0110] B fp1 =B f11 +B f12 =2B common1 +(H+1)·B airplane12 +B w1 (twenty one)

[0111] Subtracting formula (17) from formula (18), we get:

[0112] B fm1 =B f11 -B f12 = (H-1)·B airplane12 +B w2 (twenty two)

[0113] Similarly: Let formula (19) + formula (20) and formula (19) - formula (20), we can get:

[0114] B fp2 =B f21 +B f22 =2B common2 +(K+1)·B airplane22 +B w3 (twenty three)

[0115] B fm2 =B f21 -B f22 = (K-1)·B airplane22 +B w4 (twenty four)

[0116] Considering that common-mode magnetic interference is unrelated to aircraft magnetic interference, we can obtain the following results by performing correlation processing between formula (22) and formulas (17), (18), and (21) respectively:

[0117]

[0118]

[0119]

[0120] In the above formula, R f11 In formula (22), B represents... fm1 With formula (17) B f11 Correlation; R f12In formula (22), B represents... fm1 With formula (17) B f12 Correlation; R fp1 In formula (22), B represents... fm1 With formula (17) B jp1 The correlation is given by i, where i represents the i-th element of the sequence and n represents the number of elements in the sequence.

[0121] Then we can obtain:

[0122] Therefore, we can conclude that:

[0123]

[0124] B common1 = (B fp1 -(H+1)·B airplane12 ) / 2 (30)

[0125] The first common-mode magnetic signal can then be obtained. An illustrative example of the extracted first common-mode magnetic signal is shown below. Figure 4 As shown.

[0126] For step S104: In a preferred embodiment, the common-mode magnetic signal of the second magnetic probe aircraft is extracted based on the second processed signal and the third processed signal to obtain the second common-mode magnetic signal;

[0127] The second common-mode magnetic signal is extracted using the following formula:

[0128]

[0129] Among them, B common2 B is the second common-mode magnetic signal. fp2 B is the sum of the third processed signal and the fourth processed signal. fm2 is the difference between the third and fourth processed signals; K is the linear relationship coefficient between the aircraft magnetic interference in the third and fourth processed signals.

[0130] Specifically, by performing relevant processing on formula (24) with formulas (19), (20), and (23) respectively, we can obtain:

[0131]

[0132]

[0133]

[0134] In the above formula, R f21 In formula (24), B represents... fm2 With formula (19) Bf21 Correlation; R f22 In formula (24), B represents... fm2 With formula (20) B f22 Correlation; R fp2 In formula (24), B represents... fm2 With formula (23) B fp2 The correlation is given by i, where i represents the i-th element of the sequence and n represents the number of elements in the sequence.

[0135] Then we can get:

[0136]

[0137] Therefore, we can conclude that:

[0138]

[0139] B common2 = (B fp2 -(K+1)·B airplane22 ) / 2 (36)

[0140] The second common-mode magnetic signal can then be obtained. The extracted first common-mode magnetic signal is illustrated as follows: Figure 5 As shown.

[0141] For step S105, specifically, the common-mode magnetic signal can be separated using the above formula. Since the common-mode magnetic interference measured by the magnetic sensor of the first magnetic probe aircraft includes diurnal magnetic interference and the target signal, while the magnetic sensor of the second magnetic probe aircraft only contains diurnal magnetic interference, the target signal can be further extracted. The extracted target signal is illustrated as follows: Figure 6 As shown.

[0142] B target =B common1 -B common2 (37)

[0143] A schematic diagram illustrating the entire target signal extraction principle can be found here. Figure 9 .

[0144] It should be noted that, considering the changes in system and environmental magnetic noise during actual detection, the above equation holds true for a short period, but needs to be transformed into an adaptive coefficient correction system over a longer period. Therefore, the magnetic noise suppression method described above will employ a sliding window approach, with the window length generally considered to be greater than 60 seconds.

[0145] The above method can be implemented in a point-by-point operation manner, that is, the window length is N, the moving step is l, and a segment of data is processed. Finally, only the current point data is taken as the processed data; it can also be implemented such that after one sliding window operation, the processed data within the window is obtained, that is, the window length is N, the moving step is N, and a segment-by-segment processing method is adopted, and all the processed data within the sliding window is retained; it can also be implemented such that after one sliding window operation, only partial data is calculated, that is, the window length is N, the moving step is l (l < N), a segment of data is processed, and finally only partial data is retained.

[0146] Based on the above method embodiments, the present invention correspondingly provides apparatus embodiments;

[0147] As Figure 10 shown, an embodiment of the present invention provides an aviation magnetic interference suppression apparatus based on dual aircraft and multiple magnetic sensors, including: a signal receiving module, a signal preprocessing module, a first common-mode magnetic signal extraction module, a second common-mode magnetic signal extraction module, and a target signal extraction module;

[0148] The signal receiving module is configured to obtain a first magnetic field signal measured by a first magnetic sensor, a second magnetic field signal measured by a second magnetic sensor, a third magnetic field signal measured by a third magnetic sensor, and a fourth magnetic field signal measured by a fourth magnetic sensor; wherein, the first magnetic field sensor and the second magnetic sensor are disposed on a first magnetic exploration aircraft; the third magnetic field sensor and the fourth magnetic sensor are disposed on a second magnetic exploration aircraft; the first magnetic exploration aircraft and the second magnetic exploration aircraft are at the same altitude, and the altitude difference between any one of the magnetic exploration aircraft and the location of the detection target is h; the first magnetic exploration aircraft and the second magnetic exploration aircraft are separated by a distance L left and right; the detection distances of the first magnetic exploration aircraft and the second magnetic exploration aircraft are both R;

[0149] The signal preprocessing module is configured to perform signal preprocessing on the first magnetic field signal, the second magnetic field signal, the third magnetic field signal, and the fourth magnetic field signal respectively, to obtain a first processed signal, a second processed signal, a third processed signal, and a fourth processed signal; wherein, the signal preprocessing includes: platform magnetic interference compensation and filtering;

[0150] The first common-mode magnetic signal extraction module is configured to extract the common-mode magnetic signal of the first magnetic exploration aircraft according to the first processed signal and the second processed signal, to obtain a first common-mode magnetic signal;

[0151] The second common-mode magnetic signal extraction module is configured to extract the common-mode magnetic signal of the second magnetic exploration aircraft according to the second processed signal and the third processed signal, to obtain a second common-mode magnetic signal;

[0152] The target signal extraction module is used to subtract the first common-mode magnetic signal and the second common-mode magnetic signal to obtain the target signal corresponding to the detected target.

[0153] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0154] Those skilled in the art will clearly understand that, for convenience and simplicity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0155] Based on the above method embodiments, the present invention provides corresponding device embodiments;

[0156] One embodiment of the present invention provides a device comprising: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the airborne magnetic interference suppression method based on dual-machine multi-magnetic sensors as described in any one of the present invention.

[0157] The aforementioned devices may be computing devices such as desktop computers, laptops, handheld computers, and cloud servers. These devices may include, but are not limited to, processors and memory.

[0158] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the device, connecting various parts of the terminal device via various interfaces and lines.

[0159] The memory can be used to store the computer program. The processor implements various functions of the terminal device by running or executing the computer program stored in the memory and calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created based on the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, RAM, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0160] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for suppressing airborne magnetic interference based on dual-machine multi-magnetic sensors, characterized in that, include: The system acquires a first magnetic field signal measured by a first magnetic sensor, a second magnetic field signal measured by a second magnetic sensor, a third magnetic field signal measured by a third magnetic sensor, and a fourth magnetic field signal measured by a fourth magnetic sensor. The first and second magnetic sensors are mounted on a first magnetic probe aircraft; the third and fourth magnetic sensors are mounted on a second magnetic probe aircraft; the first and second magnetic probe aircraft are at the same altitude, and the altitude difference between either aircraft and the target location is h; the first and second magnetic probe aircraft are spaced L apart laterally; and the detection distance of both the first and second magnetic probe aircraft is R. ; The first magnetic field signal, the second magnetic field signal, the third magnetic field signal, and the fourth magnetic field signal are respectively preprocessed to obtain the first processed signal, the second processed signal, the third processed signal, and the fourth processed signal; wherein, the signal preprocessing includes: platform magnetic interference compensation and filtering; The common-mode magnetic signal of the first magnetic probe aircraft is extracted based on the first processed signal and the second processed signal to obtain the first common-mode magnetic signal; wherein, the first common-mode magnetic signal is extracted using the following formula: ; This is the first common-mode magnetic signal; It is the sum of the first processed signal and the second processed signal; H is the difference between the first processed signal and the second processed signal; H is the linear relationship coefficient of aircraft magnetic interference in the first processed signal and the second processed signal. The common-mode magnetic signal of the second magnetic probe aircraft is extracted based on the second processed signal and the third processed signal to obtain the second common-mode magnetic signal; wherein, the second common-mode magnetic signal is extracted using the following formula: ;in, This is the second common-mode magnetic signal; It is the sum of the third processed signal and the fourth processed signal; The difference between the third and fourth processed signals is denoted as K; K is the linear relationship coefficient between the aircraft magnetic interference in the third and fourth processed signals. The target signal corresponding to the detection target is obtained by subtracting the first common-mode magnetic signal and the second common-mode magnetic signal.

2. The airborne magnetic interference suppression method based on dual-aircraft multi-magnetic sensors as described in claim 1, characterized in that, The first magnetic sensor and the second magnetic sensor are respectively installed at the wingtips of the left and right wings of the first magnetic probe aircraft; The third magnetic sensor and the fourth magnetic sensor are respectively installed at the wingtips of the left and right wings of the second magnetic probe aircraft.

3. The airborne magnetic interference suppression method based on dual-machine multi-magnetic sensors as described in claim 1, characterized in that, The first magnetic sensor and the second magnetic sensor are mounted on the same wing of the first magnetic probe aircraft, and the first magnetic sensor and the second magnetic sensor are separated by a first preset distance; The third magnetic sensor and the fourth magnetic sensor are mounted on the same wing of the second magnetic probe aircraft, and the third magnetic sensor and the fourth magnetic sensor are spaced apart by a second preset distance.

4. An airborne magnetic interference suppression device based on dual-machine multi-magnetic sensors, characterized in that, include: The system includes a signal receiving module, a signal preprocessing module, a first common-mode magnetic signal extraction module, a second common-mode magnetic signal extraction module, and a target signal extraction module. The signal receiving module is used to acquire a first magnetic field signal measured by a first magnetic sensor, a second magnetic field signal measured by a second magnetic sensor, a third magnetic field signal measured by a third magnetic sensor, and a fourth magnetic field signal measured by a fourth magnetic sensor; wherein the first and second magnetic sensors are mounted on a first magnetic probe aircraft; the third and fourth magnetic sensors are mounted on a second magnetic probe aircraft; the first and second magnetic probe aircraft are at the same altitude, and the altitude difference between either magnetic probe aircraft and the location of the detection target is h; the first and second magnetic probe aircraft are spaced L apart laterally; and the detection distance of both the first and second magnetic probe aircraft is R. ; The signal preprocessing module is used to preprocess the first magnetic field signal, the second magnetic field signal, the third magnetic field signal, and the fourth magnetic field signal respectively to obtain the first processed signal, the second processed signal, the third processed signal, and the fourth processed signal; wherein, the signal preprocessing includes: platform magnetic interference compensation and filtering; The first common-mode magnetic signal extraction module is used to extract the common-mode magnetic signal of the first magnetic probe aircraft based on the first processed signal and the second processed signal, thereby obtaining the first common-mode magnetic signal; wherein, the first common-mode magnetic signal is extracted using the following formula: ; This is the first common-mode magnetic signal; It is the sum of the first processed signal and the second processed signal; H is the difference between the first processed signal and the second processed signal; H is the linear relationship coefficient of aircraft magnetic interference in the first processed signal and the second processed signal. The second common-mode magnetic signal extraction module is used to extract the common-mode magnetic signal of the second magnetic probe aircraft based on the second processed signal and the third processed signal, thereby obtaining the second common-mode magnetic signal; wherein, the second common-mode magnetic signal is extracted using the following formula: ;in, This is the second common-mode magnetic signal; It is the sum of the third processed signal and the fourth processed signal; The difference between the third and fourth processed signals is denoted as K; K is the linear relationship coefficient between the aircraft magnetic interference in the third and fourth processed signals. The target signal extraction module is used to subtract the first common-mode magnetic signal and the second common-mode magnetic signal to obtain the target signal corresponding to the detected target.

5. A device, characterized in that, The system includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the airborne magnetic interference suppression method based on a dual-machine multi-magnetic sensor as described in any one of claims 1 to 3.

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