A remote positioning device and real-time monitoring system for offshore islands and reefs

Abstract

The application relates to the technical field of offshore positioning, and particularly discloses a remote positioning device for offshore islands and a real-time monitoring system, which comprises a plurality of groups of positioning signal acquisition terminals, a relative position calculation module and an absolute position calculation module. The positioning signal acquisition terminals are used for acquiring positioning signals sent by offshore ships and determining the directions of the positioning signals, and the positioning signals are radio signals. The relative position calculation module is used for receiving the positioning signals and the directions of the positioning signals from the positioning signal acquisition terminals and calculating first position information of the ships sending the signals relative to the islands based on the directions of the positioning signals. The absolute position calculation module is used for performing secondary data analysis based on the calculated first position information and acquiring second position information of the ships. The real-time monitoring system realizes information interaction through an information transmission unit, acquires positioning information through a data request unit and realizes a route simulation function based on a position updating unit, so that the real-time monitoring purpose is achieved.

Description

Technical Field

[0001] This invention relates to the field of marine positioning technology, specifically to a remote positioning device and real-time monitoring system for offshore islands and reefs. Background Technology

[0002] Navigation is the activity of humans navigating the seas, crossing oceans, and traveling from one landmass to another. Navigation is paramount in navigation. Currently, there are three main methods for navigating and locating moving targets such as ships at sea: satellite navigation, inertial navigation, and radar navigation. However, in actual navigation, these three methods still have shortcomings. Satellite navigation requires a certain number of satellites for positioning; insufficient satellite coverage prevents positioning. Radar navigation relies on ground-based radar stations and can only be used in near-shore waters. Inertial navigation suffers from error accumulation, resulting in lower accuracy. Patent CN112987066B discloses a method for locating maritime targets based on the fusion of multi-system, multi-source positioning data. This method relies on acquiring data from the Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS), similar to the three aforementioned common positioning and navigation methods, making its implementation challenging.

[0003] Meanwhile, islands and reefs are often scattered at sea. Some of these islands and reefs are located in the sea and are not suitable for daily life, so there are few traces of human activity, they are relatively desolate, and the development level is low. Therefore, this invention proposes a remote positioning device and real-time monitoring system for islands and reefs at sea, which uses the desolate islands and reefs at sea as anchor points to assist in positioning and improve the safety of navigation at sea. Summary of the Invention

[0004] The purpose of this invention is to provide a remote positioning device and real-time monitoring system for offshore islands and reefs, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a remote positioning device for offshore islands and reefs, comprising:

[0006] Several sets of positioning signal acquisition terminals are used to acquire positioning signals sent by ships at sea and determine the direction of arrival of the signals, wherein the positioning signals are radio signals;

[0007] The relative position calculation module is used to receive the positioning signal of the positioning signal acquisition terminal and the direction of the incoming wave, and calculate the first position information of the ship sending the signal relative to the island and reef based on the direction of the incoming wave.

[0008] The absolute position calculation module performs secondary data analysis based on the calculated first position information to obtain the ship's second position information.

[0009] Preferably, the number of positioning signal acquisition terminals is no less than six, and they are evenly distributed in the sea area around the islands and reefs, with the distance error between different positioning signal acquisition terminals and the islands and reefs not exceeding 3 nautical miles.

[0010] Preferably, the direction of arrival of the positioning signal refers to the angle α between the direction in which the radio wave arrives at the receiver and the due north direction. i，t ;

[0011] The number of positioning signal acquisition terminals is i, i = 1, 2, 3, 4, ...; α i，t To obtain the direction of arrival of the positioning signal corresponding to the terminal at time t for the i-th positioning signal.

[0012] Preferably, the direction of arrival α of the positioning signal i，t The calculation process is as follows:

[0013] The positioning signal acquisition terminal has three sets of antenna elements in its direction-finding antenna array, denoted as C1, C2, and C3 respectively. The distances between the three sets of antenna elements are measured and denoted as D. 12 D 23 D 13 D 12 D represents the distance between antenna elements C1 and C2. 23 D represents the distance between antenna elements C2 and C3. 13 This represents the distance between antenna elements C1 and C3;

[0014] After a radio signal is detected in the direction-finding antenna array, the phase difference between the three sets of antenna elements is measured using an interferometer and denoted as β. 12 β 23 β 13 , where β 12 β represents the phase difference between antenna elements C1 and C2. 23 β represents the phase difference between antenna elements C2 and C3. 13 This represents the phase difference between antenna elements C1 and C3;

[0015] The angle between the direction in which radio waves arrive at the receiver and the right angle of the antenna's line of sight is denoted as the direction of arrival of the radio signal, and is referred to as θ.

[0016] The relationship between the phase difference β between any two sets of antenna elements and the direction of arrival θ of the wireless signal is as follows:

[0017] Where D is the distance between any two sets of antenna elements, and v is the radio propagation speed. In this formula, the speed of light is taken as a constant.

[0018] From the above equation, the direction of arrival θ of the wireless signal can be obtained:

[0019]

[0020] By substituting different antenna element distances and phase differences, three sets of arrival directions θ are obtained, denoted as θ0. 12 θ 23 θ 13 ;where θ 12 θ represents the direction of arrival of the wireless signal acquired through antenna elements C1 and C2. 23 θ represents the direction of arrival of the wireless signal acquired through antenna elements C2 and C3. 13 This indicates the direction of arrival of the wireless signal acquired through antenna elements C1 and C3;

[0021] The average value of the three arrival directions θ is obtained. but The direction of arrival of the positioning signal α i，t The relationship is:

[0022] In the formula, b is the calibration coefficient, which is related to the type of antenna and the geographical latitude and longitude, and is set by the staff.

[0023] Preferably, the relative position calculation module initializes the relative positions of the islands and reefs and several sets of positioning signal acquisition terminals, and the specific process is as follows:

[0024] A point on the island or reef is selected as the origin to establish a relative position coordinate system. The coordinate points of several sets of positioning signal acquisition terminals are marked as (l) i ,γ i ), where l i The distance γ from the origin is obtained by identifying the i-th positioning signal. i This represents the angle between the line connecting the i-th positioning signal acquisition terminal and the origin and the due north direction.

[0025] Preferably, after at least three sets of positioning signal acquisition terminals detect the positioning signal, the relative position calculation module calculates the ship's first position information, and the acquisition process is as follows:

[0026] It is determined that there are three sets of positioning signal acquisition terminals that have detected stable positioning signals. The three sets of positioning signal acquisition terminals are denoted as x, y, and z, where x, y, and z are all positive integers less than i.

[0027] Three sets of positioning signals were selected at the same time t0 to obtain the direction of arrival of the positioning signals detected by the terminal, and denoted as follows: in The representative identifier is the direction of arrival of the positioning signal corresponding to the x-th island / reef at time t0. The representative identifier is the direction of arrival of the positioning signal corresponding to the y-th island / reef at time t0. The representative identifier is the direction of arrival of the positioning signal corresponding to the z-th island / reef at time t0;

[0028] Let p be the position of the vessel that sends the positioning signal, then the first position information of the vessel relative to the island / reef is marked as (l). p ,γ p ), where l p γ represents the distance of the ship from the origin of the island / reef. p This indicates the angle between the line connecting the ship and the origin of the island / reef and due north.

[0029] Preferably, a triangle is constructed by connecting points x, y, and p, and the trigonometric function is used to calculate (l) p,xy ,γ p,xy );

[0030] Construct a triangle by connecting points x, z, and p. Then, using trigonometric functions, find (l... p,xz ,γ p,xz );

[0031] Construct a triangle by connecting points y, z, and p. Then, using trigonometric functions, find (l... p,yz ,γ p,yz );

[0032] Among them (l) p,xy ,γ p,xy () represents the coordinates of the ship's first position in the x,y reference frame, (l p,xz ,γ p,xz () represents the coordinates of the ship's first position in the x,z reference frame, (l p,yz ,γ p,yz () represents the coordinates of the ship's first position in the y,z reference frame;

[0033] Based on the coordinates of the first position information in three reference frames, the final coordinates of the first position information are determined. The specific process is as follows:

[0034] l p =λ1l p,xy +λ2l p,xz +λ3l p,yz ;

[0035]

[0036] λ1, λ2, and λ3 are correction parameters introduced during the distance calculation process, where 0 ≤ λ1 ≤ 1, 0 ≤ λ2 ≤ 1, and 0 ≤ λ3 ≤ 1. The specific values ​​are set by the staff; These are correction parameters introduced during the distance calculation process, where and The specific values ​​are set by the staff.

[0037] Preferably, the absolute position calculation module calculates the coordinates of the second position information as follows:

[0038] Determine the latitude and longitude of the origin point on the island or reef, and denot them as (m0, n0), where m0 represents the longitude of the origin point and n0 represents the latitude of the origin point;

[0039] The determined first position information of the vessel relative to the island / reef (l p ,γ p );

[0040] Obtain the ship's latitude and longitude (m) p ,n p ), which is the second position information coordinate:

[0041] m p The longitude of a ship is represented by the following formula:

[0042] n p The latitude of a ship is represented by the formula: n p =n0+l p *ω;

[0043] In the above formula ω represents the adjustment parameters, the specific values ​​of which are related to the latitude and longitude of the island / reef and γ. p The value is related to the setting by the staff.

[0044] Preferably, the present invention also provides a real-time monitoring system for offshore islands and reefs, which is based on the above-mentioned remote positioning device for offshore islands and reefs, and further includes:

[0045] The information transmission unit transmits the first and second location information acquired by the remote positioning device to the control terminal and feeds it back to the detected vessel.

[0046] The data request unit sends a data request to the remote positioning device to obtain positioning information;

[0047] The position update unit updates the ship's first and second position information in chronological order.

[0048] The route simulation unit forms location points on the simulation map of the island and reef area based on the latest first and second location information obtained by the location update unit, and forms a route simulation image by connecting the location points.

[0049] Preferably, the update logic of the route simulation unit is as follows:

[0050] Determine the time point t0 that first satisfies the position calculation requirement, and obtain the first position information and second position information of the ship at time t0, and record them as follows; This point will be taken as the initial point for the vessel within the monitoring range;

[0051] Every c time intervals, a data request is sent to the remote positioning device to obtain new first and second position information of the ship, which are then recorded as follows: Where k represents the number of times a request for a ship's position is made, k = 1, 2, 3, 4, ...;

[0052] In chronological order, the locations t0+c, t0+2c, t0+3c... are marked on the simulated map in sequence, and the marked locations are connected to form a flight path simulation image.

[0053] Preferably, the present invention also provides a computer program product stored on a computer-readable medium, including a computer-readable program that, when executed on an electronic device, provides a user input interface to implement the above-described real-time monitoring system for offshore islands and reefs.

[0054] Compared with the prior art, the beneficial effects of the present invention are:

[0055] 1. This invention mainly uses islands and reefs at sea as anchor points for positioning. Taking advantage of the fixed position of the islands and reefs in the sea, the position of ships in the surrounding sea area is obtained by setting up detection equipment on the islands and reefs, and the latitude and longitude of the ships are obtained by converting the relative position of the ships and the islands and reefs.

[0056] 2. This invention sets up several sets of positioning signal acquisition terminals, with each pair forming a reference frame, thereby obtaining the ship's position relative to multiple reference frames and improving the accuracy of positioning.

[0057] 3. The real-time monitoring system based on the positioning device can record the ship's route information and feed it back to the terminal management; at the same time, it can feed back the positioning information to the ship, so that the ship can obtain its position under some conditions where positioning is not possible, thereby improving the safety of navigation. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the remote positioning device of the present invention;

[0059] Figure 2 This is a schematic diagram of the real-time monitoring system structure of the present invention;

[0060] Figure 3 This is a schematic diagram simulating the operation of the present invention;

[0061] Figure 4 This is a diagram of the mathematical model for calculating the ship's position according to the present invention. Detailed Implementation

[0062] 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.

[0063] In the description of this invention, it should be noted that the terms "vertical," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0064] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0065] Example 1:

[0066] Please see Figure 1 This embodiment provides a remote positioning device for offshore islands and reefs, including:

[0067] Several sets of positioning signal acquisition terminals are used to acquire positioning signals sent by ships at sea and determine the direction of arrival of the signals, wherein the positioning signals are radio signals;

[0068] like Figure 3 As shown, in this embodiment, eight sets of positioning signal acquisition terminals are set up in the sea area around the islands and reefs. The eight sets of positioning signal acquisition terminals are evenly distributed around the islands and reefs, and the distance between the eight sets of positioning signal acquisition terminals and the islands and reefs is similar. The detection area covered by the eight sets of positioning signal acquisition terminals is similar to the regional outline of the islands and reefs.

[0069] The positioning signal acquisition terminal can be set up on existing small islands and reefs in the surrounding waters, or it can be set up at a fixed location in the sea area by pouring concrete pile foundations. During the setting up, it is necessary to ensure the stability and safety of the positioning signal acquisition terminal.

[0070] The basic propagation characteristics of radio signals are: they propagate in a straight line in an ideal homogeneous medium at a constant speed; and they are reflected at the interface between two media. Compared to other positioning and navigation methods, radio navigation has the advantages of being all-weather and offering high positioning accuracy and reliability.

[0071] Most of the wireless equipment on board ships is powered by the ship's emergency power supply or other backup power sources to ensure the normal operation of communication and positioning equipment while sailing at sea.

[0072] The relative position calculation module is used to receive the positioning signal of the positioning signal acquisition terminal and the direction of the incoming wave, and calculate the first position information of the ship sending the signal relative to the island and reef based on the direction of the incoming wave.

[0073] The direction of arrival of the positioning signal refers to the angle α between the direction in which the radio wave arrives at the receiver and true north. i，t In actual use, the number of positioning signal acquisition terminals is i, where i = 1, 2, 3, 4, ...; α i，t To obtain the direction of arrival of the positioning signal corresponding to the terminal at time t for the i-th positioning signal.

[0074] This angle is primarily determined by measuring the phase difference of radio waves, or it can be determined by measuring the time difference of arrival of radio waves; in this scheme, it is mainly determined by measuring the phase difference of radio waves; the specific implementation process is as follows:

[0075] In this scheme, each positioning signal acquisition terminal is equipped with three sets of antenna elements, which are used as references to each other; the three sets of antenna elements are denoted as C1, C2, and C3 respectively, and the distance between the three sets of antenna elements is measured and denoted as D. 12 D 23 D 13 D 12 D represents the distance between antenna elements C1 and C2. 23 D represents the distance between antenna elements C2 and C3. 13 This represents the distance between antenna elements C1 and C3; after a radio signal is detected in the direction-finding antenna array, the phase difference between the three sets of antenna elements is measured using an interferometer and denoted as β. 12 β 23 β 13 , where β 12 β represents the phase difference between antenna elements C1 and C2. 23 β represents the phase difference between antenna elements C2 and C3. 13 This represents the phase difference between antenna elements C1 and C3.

[0076] The angle between the direction in which radio waves arrive at the receiver and the right angle of the antenna's line of sight is denoted as the direction of arrival of the radio signal, and is referred to as θ.

[0077] The relationship between the phase difference β between any two sets of antenna elements and the direction of arrival θ of the wireless signal is as follows:

[0078] Where D is the distance between any two sets of antenna elements, and v is the radio propagation speed. In this formula, the speed of light is taken as a constant.

[0079] From the above equation, the direction of arrival θ of the wireless signal can be obtained:

[0080]

[0081] By substituting different antenna element distances and phase differences, three sets of arrival directions θ are obtained, denoted as θ0. 12 θ 23 θ 13 ;where θ 12 θ represents the direction of arrival of the wireless signal acquired through antenna elements C1 and C2. 23 θ represents the direction of arrival of the wireless signal acquired through antenna elements C2 and C3. 13 This indicates the direction of arrival of the wireless signal acquired through antenna elements C1 and C3;

[0082] The average value of the three arrival directions θ is obtained. but The direction of arrival of the positioning signal α i，t The relationship is:

[0083] In the formula, b is the calibration coefficient, the value of which is related to the type of antenna and the geographical latitude and longitude, and is set by the staff.

[0084] The absolute position calculation module performs secondary data analysis based on the calculated first position information to obtain the ship's second position information.

[0085] The relative position calculation module needs to initialize the relative positions of the islands and reefs and several sets of positioning signal acquisition terminals in advance. The specific process is as follows:

[0086] A point on the island or reef is selected as the origin to establish a relative position coordinate system. The coordinate points of several sets of positioning signal acquisition terminals are marked as (l) i ,γ i ), where l i The distance γ from the origin is obtained by identifying the i-th positioning signal. i This represents the angle between the line connecting the i-th positioning signal acquisition terminal and the origin and the due north direction.

[0087] In this process, both the island / reef and the positioning signal acquisition terminal are treated as point masses; with the island / reef as the origin, the distance l between the positioning signal acquisition terminal and the island / reef represented by each point mass is... i Angle (the angle between the line connecting the point mass and the origin and the direction of true north) γ i It is unique; each (l) i ,γ i All of these can clearly express the position of the positioning signal acquisition terminal relative to the island or reef.

[0088] When a vessel enters the wireless signal detection coverage area of ​​the positioning signal acquisition terminal, the vessel's position is detected by the positioning signal acquisition terminal; when no less than three sets of positioning signal acquisition terminals detect the positioning signal, the relative position calculation module calculates the vessel's first position information.

[0089] During the aforementioned detection process, when one positioning signal acquisition terminal detects a signal, the detection can only obtain the direction of the transmitting ship relative to the detecting terminal, but cannot determine the distance, thus the ship's exact location cannot be determined. When two positioning signal acquisition terminals detect a signal, since there is a certain distance between the detecting terminals and both terminals can determine the ship's direction relative to themselves, the ship's location can be determined at this point. However, with only two sets of data and no other data for reference, errors may occur. Therefore, in actual use, positioning is performed only after three sets of positioning signal acquisition terminals detect the signal.

[0090] Once at least three sets of positioning signal acquisition terminals detect the positioning signal, the ship's first position information is calculated, and the acquisition process is as follows:

[0091] It is determined that there are three sets of positioning signal acquisition terminals that have detected stable positioning signals. The three sets of positioning signal acquisition terminals are denoted as x, y, and z, where x, y, and z are all positive integers less than i.

[0092] Three sets of positioning signals were selected at the same time t0 to obtain the direction of arrival of the positioning signals detected by the terminal, and denoted as follows: in The representative identifier is the direction of arrival of the positioning signal corresponding to the x-th island / reef at time t0. The representative identifier is the direction of arrival of the positioning signal corresponding to the y-th island / reef at time t0. The representative identifier is the direction of arrival of the positioning signal corresponding to the z-th island / reef at time t0.

[0093] In this process, it is necessary to ensure that the wireless signals acquired at the same time t0 are received, so as to reduce the interference caused by the ship's navigation to position changes. The speed of radio waves in air or water can be regarded as the speed of light. Therefore, the time difference between the ship's radio waves and different positioning signal acquisition terminals is very small, and the position change of the ship's navigation within this time difference can be ignored.

[0094] Let p be the position of the vessel that sends the positioning signal, then the first position information of the vessel relative to the island / reef is marked as (l). p ,γ p ), where l p γ represents the distance of the ship from the origin of the island / reef. p This indicates the angle between the line connecting the ship and the origin of the island / reef and due north.

[0095] The above-mentioned first position information of the vessel (l) p ,γ p The specific calculation method is as follows:

[0096] Construct a triangle by connecting points x, y, and p. Then, using trigonometric functions, find (l... p,xy ,γ p,xy );

[0097] Construct a triangle by connecting points x, z, and p. Then, using trigonometric functions, find (l... p,xz ,γ p,xz );

[0098] Construct a triangle by connecting points y, z, and p. Then, using trigonometric functions, find (l... p,yz ,γ p,yz );

[0099] Among them (l) p,xy ,γ p,xy () represents the coordinates of the ship's first position in the x,y reference frame, (l p,xz ,γ p,xz () represents the coordinates of the ship's first position in the x,z reference frame, (l p,yz ,γ p,yz ) represents the first position information coordinates of the ship in the y,z reference frame.

[0100] (l p,xy ,γ p,xy ), (l p,xz ,γ p,xz ), (l p,yz ,γ p,yz The calculation methods for all three are the same, and the following will discuss (l) p,xy ,γ p,xyTo elaborate further, the other two sets of data can be obtained in the same way:

[0101] Please see Figure 4 The problem is transformed into a simple mathematical model. Since the detection range of the positioning signal acquisition terminal is limited in practical applications, and the influence of the angle change of the Earth's sphere is small in this area, the model is still regarded as a planar problem to a certain extent.

[0102] exist Figure 4 In this context, o, x, y, and p represent the origin, the mass points of the two sets of positioning signal acquisition terminals, and the mass point of the ship, respectively; oxyp is an arbitrary irregular planar quadrilateral. In this planar quadrilateral, the following conditions can be directly obtained: the length of ox, the length of oy, the length of xy, the value of angle oxy, and the value of angle oyx.

[0103] In triangle oxy, all three points are fixed points, and the lengths of ox and oy can be obtained directly. The angles between line segments ox and oy and the vertical direction are also fixed values. Therefore, the above conditions can also be used as known conditions.

[0104] The value of angle oxp is the angle between ox and true north minus the angle between xp and true north. Similarly, the value of angle oyp can also be calculated.

[0105] In triangle xpy, the value of angle pxy is angle oxp minus angle oxy. Similarly, the value of angle pyx can be obtained. Therefore, the values ​​of the three interior angles of triangle xpy can be obtained. Combining the lengths of xy, the values ​​of the other two sides, px and py, can be obtained directly using the law of sines.

[0106] In triangle oxp, the values ​​of px, ox, and angle oxp are known, and the values ​​of op and angle xop can be obtained directly using the Law of Cosines.

[0107] The vertical line passing through point x intersects the horizontal line passing through point o at point j, and the horizontal line passing through point o intersects the vertical line passing through point p at point e;

[0108] In triangle ojx, which is a right triangle, angle oxj can be obtained by the angle between line segment ox and the vertical direction, thus obtaining the value of angle jox, and further obtaining the angle between line segment op and the vertical direction.

[0109] The above describes the first position information coordinates of the ship in the x,y reference frame (l). p,xy ,γ p,xy The acquisition method is universal and can be used to obtain the coordinates of the other two sets of first position information.

[0110] Based on the coordinates of the first position information in three reference frames, the final coordinates of the first position information are determined. The specific process is as follows:

[0111] l p =λ1l p,xy +λ2l p,xz +λ3l p,yz ;

[0112]

[0113] λ1, λ2, and λ3 are correction parameters introduced during the distance calculation process, where 0 ≤ λ1 ≤ 1, 0 ≤ λ2 ≤ 1, and 0 ≤ λ3 ≤ 1. The specific values ​​are set by the staff; These are correction parameters introduced during the distance calculation process, where and The specific values ​​are set by the staff.

[0114] It should be noted here that: λ1 represents the influence of the distance between the ship and the origin of the island / reef calculated under the x,y reference frame on the final distance between the ship and the origin of the island / reef. Similarly, λ2 and λ3 represent the influence of the x,z and y,z reference frames on the final result, respectively. The angle between the line connecting the ship and the origin of the island / reef, as measured in the x,y reference frame, and the due north direction has a significant impact on the final result. Similarly... These represent the degree of influence of the x, z and y, z reference frames on the final result, respectively. By introducing different weighting coefficients into different reference frames, a final result value is obtained; λ1, λ2, λ3, The value can be adjusted by patent technicians according to the environmental region, thereby improving the accuracy of the results.

[0115] The absolute position calculation module calculates the coordinates of the second position information as follows:

[0116] Determine the latitude and longitude of the origin point on the island or reef, and denot them as (m0, n0), where m0 represents the longitude of the origin point and n0 represents the latitude of the origin point;

[0117] The determined first position information of the vessel relative to the island / reef (l p ,γ p );

[0118] The latitude and longitude (m) of the ship are obtained through calculation. p ,n p ), which is the second position information coordinate:

[0119] m p The longitude of a ship is represented by the following formula:

[0120] n p The latitude of a ship is represented by the formula: n p =n0+l p *ω;

[0121] In the above formula ω represents the adjustment parameters, the specific values ​​of which are related to the latitude and longitude of the island / reef and γ. p The value is related to the setting by the staff.

[0122] In different hemispheres, the location of a ship on an island or reef affects its latitude and longitude differently. For example, in the Northern Hemisphere, a ship located north of an island or reef will have a higher latitude than the island or reef. However, in the Southern Hemisphere, the same situation occurs when a ship is north of an island or reef, but its latitude is lower than the island or reef's. Similarly, longitude varies between the Eastern and Western Hemispheres. In practice, settings are determined by professionals based on the geographical conditions of the surrounding sea area. The value of ω.

[0123] Example 2: Please refer to Figure 2 The present invention also provides a real-time monitoring system for offshore islands and reefs, which is based on the aforementioned remote positioning device for offshore islands and reefs, and further includes:

[0124] The information transmission unit transmits the first and second location information acquired by the remote positioning device to the control terminal and feeds it back to the detected vessel.

[0125] The data request unit sends a data request to the remote positioning device to obtain positioning information;

[0126] The position update unit updates the ship's first and second position information in chronological order.

[0127] The route simulation unit forms location points on the simulation map of the island and reef area based on the latest first and second location information obtained by the location update unit, and forms a route simulation image by connecting the location points.

[0128] The specific implementation logic of the above-mentioned route simulation unit is as follows:

[0129] Determine the time point t0 that first satisfies the position calculation requirement, and obtain the first position information and second position information of the ship at time t0, and record them as follows; This point will be taken as the initial point for the vessel within the monitoring range;

[0130] Every c time intervals, a data request is sent to the remote positioning device to obtain new first and second position information of the ship, which are then recorded as follows: Where k represents the number of times a request for a ship's position is made, k = 1, 2, 3, 4, ...;

[0131] In this way, the ship's position can be obtained within several consecutive time intervals. In practical applications, the value of c is usually set to no more than 1 minute. The ship's speed varies depending on the ship type. Specifically, the speed of conventional cargo ships is generally between 15-20 knots, equivalent to 28 to 37 kilometers per hour; some special-type ships can reach speeds of over 40 knots; modern super container ships can reach a maximum speed of 30 knots per hour, or 55 kilometers per hour. In addition, dry bulk carriers and tankers have slower speeds, generally between 13 and 17 knots; container ships have faster speeds, with the fastest container ships reaching speeds of 24.5 knots, and passenger ships also have relatively fast speeds. Therefore, within a unit of time c, the change in the ship's position usually does not exceed 1 kilometer, and the obtained points are continuous, clearly showing even when the ship leaves the detected sea area.

[0132] In chronological order, the locations t0+c, t0+2c, t0+3c... are marked on the simulation map in sequence, and the marked locations are connected to form a flight path simulation map.

[0133] The obtained route simulation map has a high degree of continuity, and the position of the ship at a certain moment can be determined by the route map.

[0134] Example 3: This example provides a computer program product stored on a computer-readable medium, including a computer-readable program that, when executed on an electronic device, provides a user input interface to implement the above-described real-time monitoring system for offshore islands and reefs.

[0135] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A remote positioning device for offshore islands and reefs, characterized in that: include: Several sets of positioning signal acquisition terminals are used to acquire positioning signals sent by ships at sea and determine the direction of arrival of the signals, wherein the positioning signals are radio signals; The relative position calculation module is used to receive the positioning signal of the positioning signal acquisition terminal and the direction of the incoming wave, and calculate the first position information of the ship sending the signal relative to the island and reef based on the direction of the incoming wave. The absolute position calculation module performs secondary data analysis based on the calculated first position information to obtain the ship's second position information; The direction of arrival of the positioning signal refers to the angle α between the direction in which the radio wave arrives at the receiver and true north. i，t ; The number of positioning signal acquisition terminals is i, i = 1, 2, 3, 4, ...; α i，t To obtain the direction of arrival of the positioning signal corresponding to the terminal at time t for the i-th positioning signal.

2. The remote positioning device for offshore islands and reefs according to claim 1, characterized in that: The direction of arrival of the positioning signal α i，t The calculation process is as follows: The positioning signal acquisition terminal has three sets of antenna elements in its direction-finding antenna array, denoted as C1, C2, and C3 respectively. The distances between the three sets of antenna elements are measured and denoted as D. 12 D 23 D 13 D 12 D represents the distance between antenna elements C1 and C2. 23 D represents the distance between antenna elements C2 and C3. 13 This represents the distance between antenna elements C1 and C3; After a radio signal is detected in the direction-finding antenna array at time t, the phase difference between the three antenna elements is measured using an interferometer and denoted as β. 12 β 23 β 13 , where β 12 β represents the phase difference between antenna elements C1 and C2. 23 β represents the phase difference between antenna elements C2 and C3. 13 This represents the phase difference between antenna elements C1 and C3; The angle between the direction in which radio waves arrive at the receiver and the right angle of the antenna's line of sight is denoted as the direction of arrival of the radio signal, and is referred to as θ. The relationship between the phase difference β between any two sets of antenna elements and the direction of arrival θ of the wireless signal is as follows: Where D is the distance between any two sets of antenna elements, and v is the radio propagation speed. In this formula, the speed of light is taken as a constant. From the above equation, the direction of arrival θ of the wireless signal can be obtained: By substituting different antenna element distances and phase differences, three sets of arrival directions θ are obtained, denoted as θ0. 12 θ 23 θ 13 ;where θ 12 θ represents the direction of arrival of the wireless signal acquired through antenna elements C1 and C2. 23 θ represents the direction of arrival of the wireless signal acquired through antenna elements C2 and C3. 13 This indicates the direction of arrival of the wireless signal acquired through antenna elements C1 and C3; The average value of the three arrival directions θ is obtained. but The direction of arrival of the positioning signal α i，t The relationship is: In the formula, b is the calibration coefficient, which is related to the type of antenna and the geographical latitude and longitude, and is set by the staff.

3. A remote positioning device for offshore islands and reefs according to claim 1, characterized in that: The number of positioning signal acquisition terminals shall not be less than six, and they shall be evenly distributed in the sea area surrounding the islands and reefs. The distance error between different positioning signal acquisition terminals and the islands and reefs shall not exceed 3 nautical miles.

4. A remote positioning device for offshore islands and reefs according to claim 1, characterized in that: The relative position calculation module initializes the relative positions of the islands and reefs and several sets of positioning signal acquisition terminals. The specific process is as follows: A point on the island or reef is selected as the origin to establish a relative position coordinate system. The coordinate points of several sets of positioning signal acquisition terminals are marked as (l) i ,γ i ), where l i The distance γ from the origin is obtained by identifying the i-th positioning signal. i This represents the angle between the line connecting the i-th positioning signal acquisition terminal and the origin and the due north direction.

5. A remote positioning device for offshore islands and reefs according to claim 1, characterized in that: Once at least three sets of positioning signal acquisition terminals detect the positioning signal, the relative position calculation module calculates the ship's first position information, and the acquisition process is as follows: It is determined that there are three sets of positioning signal acquisition terminals that have detected stable positioning signals. The three sets of positioning signal acquisition terminals are denoted as x, y, and z, where x, y, and z are all positive integers less than i. Three sets of positioning signals were selected at the same time t0 to obtain the direction of arrival of the positioning signals detected by the terminal, and denoted as follows: in The representative identifier is the direction of arrival of the positioning signal corresponding to the x-th island / reef at time t0. The representative identifier is the direction of arrival of the positioning signal corresponding to the y-th island / reef at time t0. The representative identifier is the direction of arrival of the positioning signal corresponding to the z-th island / reef at time t0; Let p be the position of the vessel that sends the positioning signal, then the first position information of the vessel relative to the island / reef is marked as (l). p ,γ p ), where l p γ represents the distance of the ship from the origin of the island / reef. p This indicates the angle between the line connecting the ship and the origin of the island / reef and due north.

6. A remote positioning device for offshore islands and reefs according to claim 5, characterized in that: Construct a triangle by connecting points x, y, and p. Then, using trigonometric functions, find (l... p,xy ,γ p,xy ); Construct a triangle by connecting points x, z, and p. Then, using trigonometric functions, find (l... p,xz ,γ p,xz ); Construct a triangle by connecting points y, z, and p. Then, using trigonometric functions, find (l... p,yz ,γ p,yz ); Among them (l) p,xy ,γ p,xy () represents the coordinates of the ship's first position in the x,y reference frame, (l p,xz ,γ p,xz () represents the coordinates of the ship's first position in the x,z reference frame, (l p,yz ,γ p,yz () represents the coordinates of the ship's first position in the y,z reference frame; Based on the coordinates of the first position information in three reference frames, the final coordinates of the first position information are determined. The specific process is as follows: l p =λ1l p,xy +λ2l p,xz +λ3l p,yz ; λ1, λ2, and λ3 are correction parameters introduced during the distance calculation process, where 0 ≤ λ1 ≤ 1, 0 ≤ λ2 ≤ 1, and 0 ≤ λ3 ≤ 1. The specific values ​​are set by the staff; These are correction parameters introduced during the distance calculation process, where and The specific values ​​are set by the staff.

7. A remote positioning device for offshore islands and reefs according to claim 1, characterized in that: The absolute position calculation module calculates the coordinates of the second position information as follows: Determine the latitude and longitude of the origin point on the island or reef, and denot them as (m0, n0), where m0 represents the longitude of the origin point and n0 represents the latitude of the origin point; The determined first position information of the vessel relative to the island / reef (l p ,γ p ); Obtain the ship's latitude and longitude (m) p ,n p ), which is the second location information coordinate: m p The longitude of a ship is represented by the following formula: n p The latitude of a ship is represented by the formula: n p =n0+l p *ω; In the above formula ω represents the adjustment parameters, the specific values ​​of which are related to the latitude and longitude of the island / reef and γ. p The value is related to the setting by the staff.

8. A real-time monitoring system for offshore islands and reefs, characterized in that: It is implemented based on any one of claims 1 to 7, a remote positioning device for offshore islands and reefs, and further includes: The data request unit sends a data request to the remote positioning device to obtain positioning information; The position update unit updates the ship's first and second position information in chronological order. The information transmission unit transmits the first and second location information updated by the location update unit to the control terminal and feeds it back to the detected vessel; The route simulation unit forms location points on the simulation map of the island and reef area based on the latest first and second location information obtained by the location update unit, and forms a route simulation image by connecting the location points.

9. A real-time monitoring system for offshore islands and reefs according to claim 8, characterized in that: The update logic of the route simulation unit is as follows: Determine the time point t0 that first satisfies the position calculation requirement, and obtain the first position information and second position information of the ship at time t0, and record them as follows; This point will be taken as the initial point for the vessel within the monitoring range; Every c time intervals, a data request is sent to the remote positioning device to obtain new first and second position information of the ship, which are then recorded as follows: Where k represents the number of times a request for a ship's position is made, k = 1, 2, 3, 4, ...; In chronological order, the locations t0+c, t0+2c, t0+3c... are marked on the simulated map in sequence, and the marked locations are connected to form a flight path simulation image.

10. A computer program product stored on a computer-readable medium, characterized in that: It includes a computer-readable program that, when executed on an electronic device, provides a user input interface to implement a real-time monitoring system for offshore islands and reefs as described in any one of claims 8 to 9.

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