KR102127359B1 - Underwater magnetic field mapping system and method using autonomous surface vehicle - Google Patents

Abstract

The present invention relates to an underwater magnetic field mapping system and method using an autonomous watercraft, in particular, position information obtained from each of a GPS receiver, magnetometer, and attitude sensor mounted on the autonomous watercraft, 3D magnetic field vector and attitude information [Roll] , Pitch and Yaw] are transmitted to the land control room side, and the magnetic force value correction unit obtains a 3D correction value using the 3D magnetic field vector using the posture information and refers to the 3D correction value from the fixed coordinate system. Converted to a coordinate system, represented by F (total intensity), D (declination), and I (inclination), which are geomagnetic expression methods, and mapped F, D, and I to location information, and then interpolated unexplored areas using regression to obtain a high-resolution underwater magnetic field. An underwater magnetic field mapping system and method using an autonomous watercraft capable of obtaining a map.

Description

Underwater magnetic field mapping system and method using autonomous watercraft {UNDERWATER MAGNETIC FIELD MAPPING SYSTEM AND METHOD USING AUTONOMOUS SURFACE VEHICLE}

The present invention relates to an underwater magnetic field mapping system and method using an autonomous watercraft, in particular, position information obtained from each of a GPS receiver, a magnetometer and a posture sensor mounted on the autonomous watercraft, a three-dimensional magnetic field vector and posture information (Roll) , Pitch and Yaw] are transmitted to the land control room side, and the magnetic force value correction unit acquires a 3D correction value using posture information from the 3D magnetic field vector and refers to the 3D correction value in a fixed coordinate system. Converted to a coordinate system, represented by F (total intensity), D (declination), and I (inclination), which are geomagnetic expression methods, and mapped F, D, and I to location information, and then interpolated unexplored areas using a regression method to obtain a high-resolution underwater magnetic field. An underwater magnetic field mapping system and method using an autonomous watercraft capable of obtaining a map.

In general, a geomagnetic field or a geomagnetic field is a geophysical signal generated by the rotational dynamic motion (geodynamo) of the outer core of the earth, and plays an important role in protecting the earth from the solar wind. Such a magnetic field may be useful even underwater, such as inertial navigation of underwater bodies, detection of unexploded ordnance (UXO) at the seabed, and analysis of plate movement. Geomagnetic maps are also published online. Institutions such as the National Geophysical Data Center (NGDC) and the International Association of Geomagnetism and Aeronomy (IAGA) regularly model models such as the World Magnetic Model (WMM) and International Geomagnetic Reference Field (IGRF). Is provided. However, these published models have very low resolution, and models such as high-definition HDGM (High Definition Geomagnetic Model) require additional cost, which also limits the accuracy and update cycle.

In Korean Patent Publication No. 2015-0102212, a geomagnetic field strength-based map can be generated that can collect geomagnetic field values in a sample area and use them for positioning without installing additional infrastructure, and apply a fingerprint method without constructing a database in advance. An indoor positioning method is disclosed.

Since such a conventional technique is a method of collecting a geomagnetic field value of a sample area, determining a sampling interval according to the characteristics of the geomagnetic field, and collecting a geomagnetic field value according to the sampling interval to generate a geomagnetic field map, so sensing to measure the earth magnetic field Correction of the distortion phenomenon in the environment was not considered at all, and further, there was a problem that it was not suitable for generating a magnetic field map in an underwater environment in which the disturbance was severe and the algae moved.

Therefore, the present invention has been made to solve the problems as described above, and the object of the present invention is to create a high-resolution underwater magnetic field map for a sea area of interest, and the overall system is simplified and can increase the efficiency of mapping, an autonomous watercraft. It is to provide an underwater magnetic field mapping system and method using.

In order to achieve the above object, an underwater magnetic field mapping system using an autonomous watercraft according to an embodiment of the present invention includes a GPS receiver 100 mounted on an autonomous watercraft to receive microwaves from GPS satellites and generate location information; A magnetometer 110 installed under the body of the autonomous vessel to obtain a three-dimensional magnetic field vector (m); A posture sensor 120 mounted on the autonomous vessel to acquire posture information (ie, roll, pitch, and yaw); A wireless communication unit 130 mounted on the autonomous vessel and wirelessly transmitting the location information, a three-dimensional magnetic field vector (m) and posture information to the land control room side; A wireless communication unit 200 installed on the land control room side to receive and demodulate a wireless signal from the wireless communication unit 130; A data input unit 210 installed on the land control room side to receive location information, a three-dimensional magnetic field vector (m) and posture information from the wireless communication unit 200; Installed on the land control room side, the 3D magnetic field vector (m) acquires a 3D correction value (m _3d ) using attitude information, and converts the 3D correction value from a fixed coordinate system to a reference coordinate system, which is a geomagnetic expression method F (Total intensity), magnetic force value correction unit 220 represented by D (declination) and I (inclination); A mapping unit 230 installed on the land control room side to map the F (total strength), D (declination) and I (inclination) to the location information; And an unexplored area interpolation unit 240 installed on the land control room side to interpolate the unexplored area by using the regression method for the position information, F (total intensity), D (declination), and I (inclination). It is characterized by.

In the underwater magnetic field mapping system using the autonomous watercraft according to the above embodiment, the magnetometer 110 may be a fluxgate type vector sensor.

In the underwater magnetic field mapping system using the autonomous watercraft according to the above embodiment, the posture sensor 120 may be an optical fiber gyroscope.

In the underwater magnetic field mapping system using autonomous watercraft according to the above embodiment, the regression method may be a Gaussian process regression method, which is one of the nonparametric regression methods.

In order to achieve the above object, a method of generating an underwater magnetic field map using an autonomous watercraft according to another embodiment of the present invention includes: receiving a microwave from a GPS satellite by the GPS receiver 100 to generate location information; Obtaining a three-dimensional magnetic field vector (m) by the magnetometer 110; Obtaining posture information (ie, roll, pitch, and yaw) by the posture sensor 120; Inputting the location information, a three-dimensional magnetic field vector (m) and posture information into the data input unit 210 through the wireless communication units 130 and 200; Obtaining a 3D correction value (m _3d ) from the magnetic force value correcting unit 220 using the 3D magnetic field vector (m) using the posture information; Converting the three-dimensional correction value (m _3d ) from a fixed coordinate system to a reference coordinate system (M ^UTM ) by the magnetic force value correcting unit 220; Representing the reference coordinate system (M ^UTM ) by the magnetic force value correcting unit 220 as F (total intensity), D (declination), and I (inclination), which are geomagnetic expression methods; Mapping the F (total intensity), D (declination) and I (inclination) to the location information by the mapping unit 230; And the unexplored region interpolation unit 240 interpolating the unexplored region using the location information, F (total intensity), D (declination), and I (inclination) using a regression method.

)를 상기 자세 정보로부터 계산되는 로테이션 메트릭스(

)를 이용하여 [수학식 1]과 같이 참조 지자기 벡터(

)를 획득하는 단계; 상기 3차원 자기장 벡터(m)에 대해 PCA를 수행하여 얻은 m'를 기준으로 단위원(C₂)화 과정을 거쳐 [수학식 2]와 같이 자기장 벡터(

)를 획득하는 단계; 상기 자기장 벡터(

)에 스케일 인자(

)를 곱하여 [수학식 3]과 같이

를 획득하는 단계; 및 상기

와 참조 지자기 벡터(

) 사이의 3차원 변환을 [수학식 6] 및 [수학식 7]과 같이 하여 3차원 보정값(

)을 획득하는 단계를 포함할 수 있다.In the method of generating an underwater magnetic field map using an autonomous watercraft according to the other embodiment, the obtaining of the 3D correction value (m _3d ) includes: WMM (World Magnetic Model), IGRF (International Geomagnetic Reference Field), and EMM ( Enhanced Magnetic Model) provided by any one of the geomagnetic vectors (

) Is a rotation matrix calculated from the posture information (

) As shown in [Equation 1].

); Based on m'obtained by performing PCA on the 3D magnetic field vector (m), a process of forming a unit circle (C ₂ ) and then using a magnetic field vector (Equation 2)

); The magnetic field vector (

) To scale factor (

Multiply) as [Equation 3]

Obtaining a; And above

With reference geomagnetic vector(

3D transformation values between () and [Equation 6] as 3D correction values (

).

[Equation 1]

[Equation 2]

는 z축 방향 회전행렬이고,

,

및

는 각각 PCA 타원의 기울기, 장축 길이 및 단축 길이임][here,

Is a rotation matrix in the z-axis direction,

,

And

Are respectively the slope of the PCA ellipse, the long axis length and the short axis length]

[Equation 3]

는 다음의 수학식 4 및 수학식 5에 의해 계산될 수 있음][here

Can be calculated by the following equation 4 and equation 5]

[Equation 4]

는 참조 지자기의 세기 값임][here,

Is the intensity value of the reference geomagnetism]

[Equation 5]

는 i번째 참조 지자기 관측값이고,

는 원(

)의 법선 벡터이며, N은 관측값의 개수임][here,

Is the i-th reference geomagnetic observation,

Is won(

) Is the normal vector, where N is the number of observations]

[Equation 6]

[Where R is the rotation value, t is the translation linear displacement, and Kabsch is the least root mean square algorithm used for 3D transformation]

[Equation 7]

)는 다음의 [수학식 8]에 의해 획득될 수 있다.In the underwater magnetic field map creation method using the autonomous watercraft according to the other embodiment, the reference coordinate system (

) Can be obtained by the following [Equation 8].

[Equation 8]

는

의 x성분이고,

는

의 y성분이며,

는

의 z성분임][here,

The

Is the x component of

The

Is the y component of

The

Component of z]

In the method of mapping an underwater magnetic field using an autonomous watercraft according to the other embodiment, the F (total intensity) can be obtained by the following [Equation 9].

[Equation 9]

In the method of generating an underwater magnetic field map using an autonomous watercraft according to the other embodiment, the D (declination) may be obtained by the following [Equation 10].

[Equation 10]

In the method for generating an underwater magnetic field map using an autonomous watercraft according to another embodiment, the I (slope) may be obtained by the following [Equation 11].

[Equation 11]

According to an underwater magnetic field mapping system and method using an autonomous watercraft according to an embodiment of the present invention, a GPS receiver is mounted on an autonomous watercraft to receive microwaves from a GPS satellite to generate location information, and a magnetometer is located below the body of the autonomous watercraft. It is installed to obtain a 3D magnetic field vector, and a posture sensor is mounted on the autonomous watercraft to acquire posture information (i.e. roll, pitch and yaw), and a data input section is installed on the land control room side to provide the position information and the 3D magnetic field. A vector and attitude information is input, and a magnetic force value correction unit is installed at the land control room side to obtain a 3D correction value using the 3D magnetic field vector using attitude information and converts the 3D correction value from a fixed coordinate system to a reference coordinate system. It is represented by F (total intensity), D (declination), and I (inclination), which are geomagnetic expression methods, and a mapping unit is installed on the land control room side to indicate the F (total intensity), D (declination) and I (inclination) ), and an unexplored region interpolation unit is installed at the land control room side to be configured to interpolate the unexplored region using a regression method for the location information, F (total intensity), D (declination), and I (inclination). It has the outstanding effect of being able to map a high-resolution underwater magnetic field for the waters of interest, simplifying the overall system, and increasing the efficiency of mapping.

1 is a block diagram of an underwater magnetic field mapping system using autonomous watercraft according to an embodiment of the present invention.
2 is a view showing that the GPS receiver 100, magnetometer 110 and posture sensor 120 are installed on the autonomous vessel.
3 is a flowchart for explaining an underwater magnetic field mapping method using an underwater magnetic field mapping system using an autonomous watercraft according to an embodiment of the present invention.
FIG. 4 is a detailed flowchart of step S50 of obtaining the 3D correction value of FIG. 3.
5 is a diagram for explaining a method of three-dimensionally correcting a three-dimensional magnetic field vector.
6 is a diagram showing the results of mapping F (total intensity), D (declination), and I (inclination) to a NED (North east dowm) frame, wherein (a) is the raw data of the uncorrected magnetometer ( raw data), and (b) is a diagram showing the result of mapping 3D corrected data.
7 is a view showing superimposed F (overall intensity) obtained through five driving of the autonomous watercraft.
FIG. 8 is a diagram showing the results when the unexplored area interpolation is performed on the results of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a block diagram of an underwater magnetic field mapping system using an autonomous watercraft according to an embodiment of the present invention, and FIG. 2 is a GPS receiver 100, a magnetometer 110, and a posture sensor 120 installed on the autonomous watercraft It is a drawing showing that.

Underwater magnetic field mapping system using autonomous watercraft according to an embodiment of the present invention, as shown in Figures 1 and 2, GPS receiver 100, magnetometer 110, posture sensor 120, wireless communication unit 130 ), a wireless communication unit 200, a data input unit 210, a magnetic force value correction unit 220, a mapping unit 230, and an unexplored area interpolation unit 240.

The GPS receiver 100 is mounted on the body of an autonomous surface vehicle (ASV) and receives microwaves from GPS satellites to generate location information.

를 획득하는 벡터 센서이다. 자력계(110)는 예컨대, 플럭스게이트(fluxgate) 타입 벡터센서를 사용할 수 있다. 한편, 획득되는 3차원 자기장 벡터(m)는 고정좌표계에서 측정된 자기장 값이다.The magnetometer 110 is installed at a predetermined distance below the body of the autonomous watercraft to provide a three-dimensional magnetic field vector.

It is a vector sensor to acquire. The magnetometer 110 may use, for example, a fluxgate type vector sensor. Meanwhile, the obtained 3D magnetic field vector (m) is a magnetic field value measured in a fixed coordinate system.

The posture sensor 120 is mounted on the body of the autonomous watercraft and serves to acquire posture information (ie, roll, pitch, and yaw). The posture sensor 120 may use, for example, an optical fiber gyroscope (BFF). Posture information is then used for 3D correction.

The wireless communication unit 130 is mounted on an autonomous vessel and wirelessly transmits location information, three-dimensional magnetic field vector (m) and attitude information from the GPS receiver 100, magnetometer 110, and attitude sensor 120 to the land control room. Plays a role.

The wireless communication unit 200 is installed on the land control room side and serves to receive and demodulate a wireless signal from the wireless communication unit 130.

The communication method of the wireless communication units 130 and 200 can be freely selected as long as it is a method that enables wireless communication between the autonomous vessel and the land control room.

The data input unit 210 is installed on the land control room side and serves to receive demodulated position information, a 3D magnetic field vector (m), and attitude information from the wireless communication unit 200.

Self-value correction section 220 hayeoseo 3D corrected using the three-dimensional magnetic field vector (m) position information is provided to the terrestrial control measured obtain a three-dimensional correction value (m _3d), and the three-dimensional correction value (m _3d ) Is converted from a fixed coordinate system to a reference coordinate system, and is represented by F (total intensity), D (declination) and I (inclination), which are geomagnetic expression methods. For 3D correction, refer to the 3D correction value acquisition step (S50) described below.

In general, in the case of a magnetometer, a distorted observation is made due to a magnetic material or an electromagnetic field around it, but without correcting it properly, an actual magnetic field value cannot be obtained. In the present invention, the magnetometer 110 is attached to be spaced apart from the autonomous watercraft by a certain distance, but is still affected by the electric field and the propulsion of the autonomous watercraft, so 3D correction is necessary.

The mapping unit 230 is installed on the land control room side and maps F (total intensity), D (deflection), and I (inclination) obtained from the magnetic force value correction unit 220 to the location information generated by the GPS receiver 100. Plays a role.

The unexplored area interpolation unit 240 is installed on the land control room side and the F (total intensity), D (deflection), and I (inclination) obtained from the position information generated by the GPS receiver 100 and the magnetic force value correction unit 220 ) To interpolate unexplored areas using regression. As the regression method, a Gaussian process regression method, which is one of the nonparametric regression methods, may be used.

The reason for interpolating the unexplored area is to obtain a high-resolution map by compacting a sparse underwater magnetic field map initially generated by driving the autonomous watercraft.

Hereinafter, an underwater magnetic field mapping method using an underwater magnetic field mapping system using an autonomous watercraft according to an embodiment of the present invention configured as described above will be described.

3 is a flowchart for explaining an underwater magnetic field mapping method using an underwater magnetic field mapping system using an autonomous watercraft according to an embodiment of the present invention, and FIG. 4 is a step of obtaining a 3D correction value of FIG. 3 ( S50) as a detailed flowchart, where S represents a step.

First, the GPS receiving unit 100 receives microwaves from a GPS satellite to generate location information (S10).

)를 획득하며(S20), 자세센서(120)에 의해 자세 정보(즉, 롤, 피치 및 요)를 획득한다(S30).At this time, the three-dimensional magnetic field vector in the magnetometer 110 (

) (S20), and posture information (ie, roll, pitch, and yaw) is acquired by the posture sensor 120 (S30).

Subsequently, location information, a 3D magnetic field vector (m), and attitude information are input to the data input unit 210 through the wireless communication units 130 and 200 (S40 ).

Then, the magnetic force value correcting unit 220 receives position information, a 3D magnetic field vector (m), and attitude information from the data input unit 210, and 3D corrects the 3D magnetic field vector (m) using attitude information. The dimensional correction value m _3d is obtained (S50 ).

This step S50 will be described in detail with reference to FIG. 4.

)를 자세 정보(롤, 피치 및 요)로부터 계산되는 로테이션 메트릭스(

)를 이용하여 [수학식 1]과 같이 참조 지자기 벡터(

)를 획득한다.First, in step S51, the magnetic force value correcting unit 220 is a geomagnetic vector (WMM) provided from any one of the World Magnetic Model (IGM), International Geomagnetic Reference Field (IGRF), and Enhanced Magnetic Model (EMM) (

) Is a rotation matrix calculated from attitude information (roll, pitch, and yaw)

) As shown in [Equation 1].

).

[Equation 1]

)를 획득한다(도 5 참조),In step S52, the magnetic force value correcting unit 220 obtains m'by performing a Principal Component Analysis (PCA) on the 3D magnetic field vector m, and based on this m', the unit circle C _{2 is} formed. And then the magnetic field vector (Equation 2)

) (See Fig. 5),

[Equation 2]

는 z축 방향 회전행렬이고,

,

및

는 각각 PCA 타원의 기울기, 장축 길이 및 단축 길이임][here,

Is a rotation matrix in the z-axis direction,

,

And

Are respectively the slope of the PCA ellipse, the long axis length and the short axis length]

)에 스케일 인자(

)를 곱하여 [수학식 3]과 같이

를 획득한다.In step S53, the magnetic field vector obtained in step S52 (

) To scale factor (

Multiply) as [Equation 3]

To acquire.

[Equation 3]

는 다음의 수학식 4 및 수학식 5에 의해 계산될 수 있음][here,

Can be calculated by the following equation 4 and equation 5]

[Equation 4]

는 참조 지자기의 세기 값임][here,

Is the intensity value of the reference geomagnetism]

[Equation 5]

는 i번째 참조 지자기 관측값이고,

는 원(

)의 법선 벡터이며, N은 관측값의 개수임][here,

Is the i-th reference geomagnetic observation,

Is won(

) Is the normal vector, where N is the number of observations]

와 참조 지자기 벡터(

) 사이의 3차원 변환을 [수학식 6] 및 [수학식 7]과 같이 하여 3차원 보정값(

)을 획득한다.In step S54, obtained in step S53

With reference geomagnetic vector(

3D transformation values between () and [Equation 6] as 3D correction values (

).

[Equation 6]

[Here, R is the rotation value, t is the translation linear displacement, and Kabsch is the least root mean square algorithm used for 3D transformation.]

[Equation 7]

Subsequently, the magnetic force value correcting unit 220 converts the three-dimensional correction value m _3d obtained in step S50 from the fixed coordinate system to the reference coordinate system M ^UTM (S60 ).

)는 다음의 [수학식 8]에 의해 획득된다.Reference coordinate system (

) Is obtained by the following [Equation 8].

[Equation 8]

는

의 x성분이고,

는

의 y성분이며,

는

의 z성분임][here,

The

Is the x component of

The

Is the y component of

The

Component of z]

Subsequently, the magnetic force value correcting unit 220 represents the reference coordinate system M ^UTM obtained in step S60 as F (total intensity), D (declination), and I (inclination), which are geomagnetic expression methods (S70).

F (total strength) is obtained by the following [Equation 9].

[Equation 9]

D (declination) is obtained by the following [Equation 10].

[Equation 10]

I (slope) is obtained by the following [Equation 11].

[Equation 11]

Subsequently, the mapping unit 230 maps the F (total intensity), D (declination), and I (inclination) obtained in step S70 to the location information generated by the GPS receiver 100 (S80).

Thereafter, the unexplored area interpolation unit 240 interpolates the unexplored area using the regression method of position information, F (total intensity), D (declination), and I (inclination) (S90), and is initially generated by driving the autonomous watercraft. A high-quality map can be obtained by densifying the old sparse map.

6 is a diagram showing the results of mapping F (total intensity), D (declination), and I (inclination) to a NED (North east dowm) frame, wherein (a) is raw data (observation of an uncorrected magnetometer) raw data), and (b) is a diagram showing the result of mapping 3D corrected data.

In the case of uncorrected observations, it appears in an inclined ellipse shape due to sensor distortion, and the reference geomagnetic observations appear in an inclined circle shape due to horizontal mismatch of the autonomous aqueous line and magnetometer 110 and the posture sensor 120 [Fig. 6]. (A)].

On the other hand, in the case of the 3D correction performed by the present invention, horizontal misalignment can be reflected by performing transformation in 3D based on the reference geomagnetic value (see FIG. 6(b)).

FIG. 7 is a diagram showing superimposed F (overall intensity) obtained through 5 travels of the autonomous watercraft, and FIG. 8 is a diagram showing results when unexplored region interpolation is performed on the results of FIG. 7.

Relatively high magnetic field values can be observed in the middle of the search region, presumably due to the geophysical properties of the crust component below the lake. Given that only the high-resolution EMAG2-v3 among the published geomagnetic data has a grid unit of 2 arcminute (about 3 km), it can be seen that the prepared geomagnetic map has a very high resolution.

According to an underwater magnetic field mapping system and method using an autonomous watercraft according to an embodiment of the present invention, a GPS receiver is mounted on an autonomous watercraft to receive microwaves from a GPS satellite to generate location information, and a magnetometer is located at the bottom of the autonomous watercraft body It is installed to obtain a 3D magnetic field vector, and a posture sensor is mounted on the autonomous watercraft to acquire posture information (i.e. roll, pitch and yaw), and a data input section is installed on the land control room side to provide the position information and the 3D magnetic field. A vector and attitude information is input, and a magnetic force value correction unit is installed at the land control room side to obtain a 3D correction value using the 3D magnetic field vector using attitude information and converts the 3D correction value from a fixed coordinate system to a reference coordinate system. It is represented by F (total intensity), D (declination), and I (inclination), which are geomagnetic expression methods, and a mapping unit is installed on the land control room side to indicate the F (total intensity), D (declination) and I (inclination) ), and an unexplored region interpolation unit is installed at the land control room side to be configured to interpolate the unexplored region using a regression method for the location information, F (total intensity), D (declination), and I (inclination). High-resolution underwater magnetic field maps for the waters of interest can be created, the overall system is simplified, and the efficiency of mapping is improved.

In the drawings and the specification, an optimal embodiment has been disclosed, and specific terms have been used, but this is only for the purpose of describing the embodiments of the present invention, and is used to limit the meaning or to limit the scope of the present invention described in the claims. It is not done. Therefore, those skilled in the art will appreciate that various modifications and other equivalent embodiments are possible. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: GPS receiver
110: magnetometer
120: posture sensor
130: wireless communication unit
200: wireless communication unit
210: data input unit
220: magnetic force correction unit
230: mapping unit
240: unexplored area interpolation part

Claims (10)

A GPS receiver 100 mounted on an autonomous vessel and generating location information by receiving microwaves from a GPS satellite;
A magnetometer 110 installed under the body of the autonomous vessel to obtain a three-dimensional magnetic field vector (m);
A posture sensor 120 mounted on the autonomous vessel to acquire posture information (ie, roll, pitch, and yaw);
A wireless communication unit 130 mounted on the autonomous vessel and wirelessly transmitting the location information, a three-dimensional magnetic field vector (m) and posture information to the land control room side;
A wireless communication unit 200 installed on the land control room side to receive and demodulate a wireless signal from the wireless communication unit 130; And
A data input unit 210 installed on the land control room side to receive location information, a three-dimensional magnetic field vector (m) and posture information from the wireless communication unit 200;
Installed on the land control room side, the 3D magnetic field vector (m) acquires a 3D correction value (m _3d ) using attitude information, and converts the 3D correction value from a fixed coordinate system to a reference coordinate system, which is a geomagnetic expression method F (Total intensity), magnetic force value correction unit 220 represented by D (declination) and I (inclination);
A mapping unit 230 installed on the land control room side to map the F (total strength), D (declination) and I (inclination) to the location information; And
It includes a non-exploration area interpolation unit 240 installed on the land control room side to interpolate the unexplored area by using the location information, F (total intensity), D (declination) and I (inclination) regression method.
The three-dimensional correction value (m _3d ),
Geomagnetic vector provided by any one of WMM (World Magnetic Model), IGRF (International Geomagnetic Reference Field) and EMM (Enhanced Magnetic Model)

) Is a rotation matrix calculated from the posture information (

) As shown in [Equation 1].

);
Based on m'obtained by performing PCA on the 3D magnetic field vector (m), a magnetic field vector (such as [Equation 2]) is obtained through the process of forming a unit circle (C ₂ ).

);
The magnetic field vector (

) To scale factor (

Multiply) as [Equation 3]

Obtaining a; And
remind

With reference geomagnetic vector(

3D transformation value between () and [Equation 6] as 3D correction value (

Acquiring); Acquired by performing, Underwater magnetic field mapping system using autonomous watercraft.

[Equation 1]

[Equation 2]

[here,

Is a rotation matrix in the z-axis direction,

,

And

Are respectively the slope of the PCA ellipse, the long axis length and the short axis length]

[Equation 3]

[here

Can be calculated by the following equation 4 and equation 5]

[Equation 4]

[here,

Is the intensity value of the reference geomagnetism]

[Equation 5]

[here,

Is the i-th reference geomagnetic observation,

Is won(

) Is the normal vector, N is the number of observations]

[Equation 6]

[Where R is the rotation value, t is the translation linear displacement, and Kabsch is the least root mean square algorithm used for 3D transformation]

[Equation 7]

According to claim 1,
The magnetometer 110 is a fluxgate type vector sensor, an underwater magnetic field mapping system using autonomous watercraft. According to claim 1,
The posture sensor 120 is a fiber optic gyroscope, an underwater magnetic field mapping system using autonomous watercraft. According to claim 1,
The regression method is a Gaussian process regression method, which is one of the nonparametric regression methods, and an underwater magnetic field mapping system using an autonomous water line. As an underwater magnetic field mapping method using the underwater magnetic field mapping system using the autonomous watercraft described in claim 1:
Generating location information by receiving microwaves from a GPS satellite by the GPS receiver 100;
Obtaining a three-dimensional magnetic field vector (m) by the magnetometer 110;
Obtaining posture information (ie, roll, pitch, and yaw) by the posture sensor 120;
Inputting the location information, a three-dimensional magnetic field vector (m) and posture information into the data input unit 210 through the wireless communication units 130 and 200;
Obtaining a 3D correction value (m _3d ) from the magnetic force value correcting unit 220 using the 3D magnetic field vector (m) using the posture information;
Converting the three-dimensional correction value (m _3d ) from a fixed coordinate system to a reference coordinate system (M ^UTM ) by the magnetic force value correcting unit 220;
Representing the reference coordinate system (M ^UTM ) by the magnetic force value correcting unit 220 as F (total intensity), D (declination), and I (inclination), which are geomagnetic expression methods;
Mapping the F (total intensity), D (declination) and I (inclination) to the location information by the mapping unit 230; And
The unexplored region interpolation unit 240 includes interpolating the unexplored region using the regression method for the location information, F (total intensity), D (declination), and I (inclination). How to map. The method of claim 5,
The step of obtaining the 3D correction value (m _3d ) is
A geomagnetic vector provided by any one of WMM (World Magnetic Model), IGRF (International Geomagnetic Reference Field) and EMM (Enhanced Magnetic Model)

) Is a rotation matrix calculated from the posture information (

) As shown in [Equation 1].

);
Based on m'obtained by performing PCA on the 3D magnetic field vector (m), a process of forming a unit circle (C ₂ ) and then using a magnetic field vector (Equation 2)

);
The magnetic field vector (

) To scale factor (

Multiply) as [Equation 3]

Obtaining a; And
remind

With reference geomagnetic vector(

3D transformation values between () and [Equation 6] as 3D correction values (

A method of mapping an underwater magnetic field using an autonomous watercraft, comprising the steps of obtaining ).

[Equation 1]

[Equation 2]

[here,

Is a rotation matrix in the z-axis direction,

,

And

Are respectively the slope of the PCA ellipse, the long axis length and the short axis length]

[Equation 3]

[here

Can be calculated by the following equation 4 and equation 5]

[Equation 4]

[here,

Is the intensity value of the reference geomagnetism]


[Equation 5]

[here,

Is the i-th reference geomagnetic observation,

Is won(

) Is the normal vector, where N is the number of observations]

[Equation 6]

[Where R is the rotation value, t is the translation linear displacement, and Kabsch is the least root mean square algorithm used for 3D transformation]

[Equation 7]

The method of claim 6,
The reference coordinate system (

) Is obtained by the following [Equation 8], underwater magnetic field mapping method using an autonomous watercraft.

[Equation 8]

[here,

The

Is the x component of

The

Is the y component of

The

Component of z] The method of claim 7,
The F (total intensity) is obtained by the following [Equation 9], underwater magnetic field mapping method using an autonomous watercraft.

[Equation 9]

The method of claim 7,
The D (declination) is obtained by the following [Equation 10], underwater magnetic field mapping method using an autonomous watercraft.

[Equation 10]

The method of claim 7,
The I (tilt) is obtained by the following [Equation 11], a method of mapping an underwater magnetic field using an autonomous watercraft.

[Equation 11]

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