Multi-satellite autonomous cooperation method for wide-area searching and tracking of marine moving target

Abstract

The invention discloses a multi-satellite autonomous cooperation method for wide-area searching and tracking of a maritime moving target, and the method comprises the steps: S1, carrying out the preliminary observation of a set maritime target region through a high-orbit satellite, obtaining rough target information, and transmitting the rough target information to a ground station in real time; s2, the ground station forms an initial marine target situation list; s3, the ground station generates a high and low orbit satellite observation demand list according to the marine target situation list; s4, the ground station plans a task sequence of the satellite at the current moment according to the high and low orbit satellite observation demand information and sends the task sequence to the corresponding satellite, and the corresponding satellite executes the task sequence and feeds back an observation result to the ground station; and S5, the ground station updates the sea target situation list according to the observation results of the corresponding satellites, and the step S3 is returned to realize wide-area search and continuous tracking of the sea target. According to the invention, situation updating and prediction can be carried out according to dynamic information, dynamic observation requirements are automatically generated, and a satellite can rapidly plan task response requirements.

Description

Technical Field

[0001] The invention belongs to the field of satellite search algorithms and relates to a multi-satellite autonomous coordination method for wide-area search and tracking of mobile targets at sea. Background Art

[0002] Due to the uncertainty of observation needs and the requirements of real-time planning, the problem of satellite mission planning has become extremely challenging. Limited by the untimely communication and the fact that it usually takes a certain amount of time for our search platform to reach the target sea area, there will inevitably be a certain deviation between the real-time position of the mobile target and the location shown by the information intelligence. We can only infer its approximate location and implement the search based on the target's sighting location, mobility, and previous movement patterns. The actual situation is complicated, and the communication in the far sea cannot be guaranteed. The electronic radar payload will lose data when the target is electronically silent, with poor reliability and low positioning accuracy. In contrast, the reliability and positioning accuracy of optical observation methods are much higher. Satellite wide-area search for mobile targets at sea is a satellite mission planning method for the above-mentioned dynamic and time-sensitive application scenarios: that is, according to the observation needs of users arriving dynamically and the real-time planning requirements of users, planning decisions are given immediately, quickly, and reasonably to improve the utilization efficiency and observation benefits of satellites. Conducting satellite wide-area search research helps to improve the rapid response capability of the entire satellite earth observation system and improve the application benefits of the earth observation system, which has important theoretical and application value. Existing satellite mission planning research is mostly oriented towards pre-collected and determined observation requirements. Modeling mostly adopts combinatorial optimization or machine scheduling models, and solving models mostly adopts optimization or intelligent optimization algorithms. These studies do not consider the situation where observation requirements are raised at any time; at the same time, in these models, the satellite mission planning problem belongs to an NPHard problem, and the difficulty and time consumption of its search and optimization increase sharply with the increase of the problem scale, making it difficult to adapt to the high timeliness requirements of satellite online scheduling. In the current application status at home and abroad, the generation of reconnaissance requirements is based on manual proposals, and there are few studies on algorithms for automatically generating satellite observation requirements. In the process of reconnaissance of time-sensitive targets in the sea and air, due to the high timeliness of observation of mobile targets, manual observation requirements may result in excessive time consumption and omission of enemy targets. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and propose a multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea, which can update and predict the situation according to dynamic information, and autonomously generate dynamic observation needs, so that satellites can quickly plan missions to respond to needs.

[0004] The solution of the present invention is:

[0005] A multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea, comprising the following steps:

[0006] S1. The high-orbit satellite conducts preliminary observation of the set marine target area, obtains rough target information, and sends it to the ground station in real time;

[0007] S2. The ground station forms an initial list of maritime target situations based on the rough target information observed by the high-orbit satellite;

[0008] S3. The ground station generates a list of high and low orbit satellite observation requirements based on the maritime target situation list;

[0009] S4. The ground station plans the task sequence of the satellite at the current moment according to the observation demand information of the high and low orbit satellites and sends it to the corresponding satellite. The corresponding satellite executes the task sequence and feeds back the observation results to the ground station.

[0010] S5. The ground station updates the maritime target situation list according to the observation results of each corresponding satellite, and returns to step S3 to achieve wide-area search and continuous tracking of maritime targets.

[0011] Preferably, the multiple satellites include one high-orbit satellite and multiple low-orbit satellites.

[0012] Preferably, in step S1, the method for the high-orbit satellite to conduct preliminary observation of the set marine target area is as follows:

[0013] The high-orbit satellite first calculates the number of preliminary observations based on the single observation range and the set marine target area range. a and b represent the length and width of the target area at sea. a , l b Indicates the length and width of a single observation range of a high-orbit satellite;

[0014] The area of ​​each observation is planned according to the number of preliminary observations, and the set offshore target area is divided into x columns and y rows, where The distance between the center coordinates of adjacent segmented regions in each column is l a , the center coordinates of adjacent segmented regions in each row are l apart b ;

[0015] The high-orbit satellite conducts a snake-like search from top to bottom for each segmented area in turn;

[0016] The observation time sequence is determined according to the high-orbit satellite observation time interval constraint, and the high-orbit satellite observation time interval constraint is determined by the satellite payload maneuverability.

[0017] Preferably, the situation list information includes the category, location, latest observation time, observation means, and category confidence of the observed target.

[0018] Preferably, the method for obtaining the situation list information is as follows:

[0019] In the target search phase, corresponding to the first round of high-orbit observation, the ground station adds the rough target information observed by the high-orbit satellite to the situation list. The rough target information includes the target position, the latest observation time, and the observation method; the target category is marked as pending confirmation, and the category confidence is marked as empty;

[0020] During the target confirmation and tracking phase, the ground station receives accurate target information from low-orbit satellite observations. The accurate target information includes the category, category confidence position, heading, speed, latest observation time, and observation method of the observed target. After associating and fusion, it is updated to the situation list to make the situation list the latest information.

[0021] Preferably, in step S3, the ground station generates a low-orbit satellite observation requirement list according to the marine target situation list, and the low-orbit satellite observation requirement list includes target sequence number, target position, target observation priority, and observation means;

[0022] The target position is predicted based on the current situation list and the observation time difference T;

[0023] The target observation priority λ is calculated based on the target category importance Q and the observation time difference T:

[0024] Among them, α and β represent the target observation priority weight parameter and the observation time difference weight parameter respectively;

[0025] Observation time difference T = current time - last observation time.

[0026] Preferably, in step S3, the ground station generates a high-orbit satellite observation requirement list according to the marine target situation list, and the high-orbit satellite observation requirement list includes the observation area center point position and the observation area priority;

[0027] Taking the single observation range of the high-orbit satellite as the reference unit, traverse the set marine target area with a step length of s. In each reference unit, calculate the sum of the target observation priorities of all targets as the observation priority of the corresponding reference unit;

[0028] All benchmark units are added as observation areas to the high-orbit satellite observation requirements list.

[0029] Preferably, the step length s includes a lateral step length and a longitudinal step length.

[0030] Preferably, in step S4, the method for planning the mission sequence of the satellite at the current moment is as follows:

[0031] According to the high-orbit satellite observation time interval constraint, check whether the high-orbit satellite can perform the observation task at the current moment. If it can, calculate the probability of each requirement in the high-orbit satellite observation requirement list being selected, and extract the requirement as the observation task at the current moment according to the probability;

[0032] Select a low-orbit satellite that can perform the observation task at the current moment, and according to the low-orbit satellite observation demand list and the target observation priority order, assign the observation demand as a task to the low-orbit satellite that meets the observation conditions and whose sub-satellite point is closest to the target position.

[0033] Preferably, the probability of the i-th requirement being selected is where λ i is the target observation priority corresponding to the i-th requirement, and n is the total number of requirements in the high-orbit satellite observation requirement list.

[0034] The beneficial effects of the present invention compared with the prior art are:

[0035] The present invention fully integrates satellite observation information to update the situation, improves the accuracy and real-time nature of the information, and solves the problem of long satellite over-the-top time intervals and untimely situation information updates through situation update and prediction methods;

[0036] The present invention can autonomously generate dynamic observation requirements according to situation changes, ensuring the real-time and accuracy of the observation requirements.

[0037] The present invention prioritizes the satellite response planning tasks that are about to pass overhead through task planning, and significantly reduces the amount of calculation compared to iterative optimization algorithms such as particle swarm optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the present invention;

[0039] Figure 2 The high-orbit satellite observation view of the mission area, where (a) is the global view and (b) is the local view;

[0040] Figure 3 The low-orbit satellite observation view of the mission area, where (a) is the global view and (b) is the local view;

[0041] Figure 4 For simulation results. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings.

[0043] High-orbit satellites have a larger observation range and a longer observation time interval, while low-orbit satellites have a smaller observation range and a shorter observation time interval. Compared with high-orbit satellites, low-orbit satellites have higher observation accuracy, and targets observed by high-orbit satellites often need to be further explored by low-orbit satellites.

[0044] The multi-satellite of the present invention comprises a high-orbit satellite and a plurality of low-orbit satellites.

[0045] like Figure 1 As shown, the specific steps include:

[0046] S1. The high-orbit satellite conducts preliminary observations of the designated target area at sea, obtains rough target information, and sends it to the ground station in real time.

[0047] The high-orbit satellite first calculates the number of preliminary observations based on the single observation range and the set marine target area range. a and b represent the length and width of the target area at sea. a , l b Indicates the length and width of a single observation range of a high-orbit satellite;

[0048] The area of ​​each observation is planned according to the number of preliminary observations, and the set offshore target area is divided into x columns and y rows, where The distance between the center coordinates of adjacent segmented regions in each column is l a , the center coordinates of adjacent segmented regions in each row are l apart b ;

[0049] The high-orbit satellite conducts a snake-like search from top to bottom for each segmented area in turn;

[0050] The observation time sequence is determined according to the high-orbit satellite observation time interval constraint, and the high-orbit satellite observation time interval constraint is determined by the satellite payload maneuverability.

[0051] S2. The ground station forms an initial marine target situation list based on the rough target information observed by the high-orbit satellite. The situation list information includes the category, location, latest observation time, observation method, and category confidence of the observed target.

[0052] The method for obtaining situation list information is as follows:

[0053] In the target search phase, corresponding to the first round of high-orbit observation, the ground station adds the rough target information observed by the high-orbit satellite to the situation list. The rough target information includes the target position, the latest observation time, and the observation method; the target category is marked as pending confirmation, and the category confidence is marked as empty;

[0054] During the target confirmation and tracking phase, the ground station receives accurate target information from low-orbit satellite observations. The accurate target information includes the category, category confidence position, heading, speed, latest observation time, and observation method of the observed target. After associating and fusion, it is updated to the situation list to make the situation list the latest information.

[0055] The association fusion method is as follows:

[0056] After receiving the observation information of the high-orbit satellite, traverse all the target positions in the current situation list to find the target p with the minimum distance from the current high-orbit satellite observation information. If the minimum distance exceeds the preset threshold, the current high-orbit satellite observation information is used as a new target and added to the situation list; if the minimum distance does not exceed the preset threshold, in the current situation list, the current high-orbit satellite observation information is used to update the information of target p except the target category, and the target category remains unchanged.

[0057] After receiving the observation information of the low-orbit satellite, traverse all the target positions in the current situation list to find the target q with the minimum distance from the current low-orbit satellite observation information. If the minimum distance exceeds the preset threshold, the current low-orbit satellite observation information is added to the situation list as a new target; if the minimum distance does not exceed the preset threshold, in the current situation list, all information of target q is updated using the current low-orbit satellite observation information.

[0058] S3. The ground station generates a list of high and low orbit satellite observation requirements based on the maritime target situation list.

[0059] The ground station generates a low-orbit satellite observation requirement list according to the marine target situation list, wherein the low-orbit satellite observation requirement list includes a target sequence number, a target position, a target observation priority, and an observation method;

[0060] The target position is predicted based on the current situation list and the observation time difference T, as follows:

[0061] For targets whose categories have been determined in the situation list, the displacement of the target within the observation time difference T is calculated based on the observation time difference T and the speed in the current situation list, and the target position in the low-orbit satellite observation demand list is predicted based on this.

[0062] The observation method is determined by the current marine environment, including electronic observation, SAR observation, and optical observation. There may be interference from objects such as clouds in the observation area, resulting in low visibility. Different observation methods are selected according to different observation accuracy requirements.

[0063] The target observation priority λ is calculated based on the target category importance Q and the observation time difference T:

[0064] Among them, α and β represent the target observation priority weight parameter and the observation time difference weight parameter, respectively, which are determined according to the number of targets that have been confirmed by low-orbit satellite observations.

[0065] The category importance of the target, Q: if the target is a target to be confirmed, Q = 5; if the target is a destroyer, Q = 4; if the target is a frigate, Q = 3; if the target is a large unmanned ship, Q = 2; if the target is a small unmanned ship, Q = 1;

[0066] Observation time difference T = current time - last observation time.

[0067] The ground station generates a high-orbit satellite observation requirement list according to the maritime target situation list, wherein the high-orbit satellite observation requirement list includes the location of the center point of the observation area and the priority of the observation area;

[0068] Taking the single observation range of the high-orbit satellite as the reference unit, the set maritime target area is traversed with a step length s. In each reference unit, the sum of the target observation priorities of all targets is calculated as the observation priority of the corresponding reference unit; the step length s includes the lateral step length and the longitudinal step length.

[0069] All benchmark units are added as observation areas to the high-orbit satellite observation requirements list.

[0070] S4. The ground station plans the current satellite task sequence based on the observation demand information of high and low orbit satellites and sends it to the corresponding satellite. The corresponding satellite executes the task sequence and feeds back the observation results to the ground station.

[0071] The method for planning the mission sequence of the satellite at the current moment is as follows:

[0072] According to the high-orbit satellite observation time interval constraint, check whether the high-orbit satellite can perform the observation task at the current moment. If it can, calculate the probability of each requirement in the high-orbit satellite observation requirement list being selected, and extract the requirement as the observation task at the current moment according to the probability;

[0073] Select a low-orbit satellite that can perform the observation task at the current moment, and according to the low-orbit satellite observation demand list and the target observation priority order, assign the observation demand as a task to the low-orbit satellite that meets the observation conditions and whose sub-satellite point is closest to the target position.

[0074] The observation task includes the observation satellite number and the center point position of the observation area.

[0075] Meeting the observation conditions means meeting the following requirements at the same time:

[0076] The observation demand center point is within the observable range of the satellite;

[0077] The types of observation satellite payloads match the observation methods required in the observation needs

[0078] Satisfy the observation time interval constraint.

[0079] The probability that the i-th demand is selected is where λ i is the target observation priority corresponding to the i-th requirement, and n is the total number of requirements in the high-orbit satellite observation requirement list.

[0080] S5. The ground station updates the maritime target situation list according to the observation results of each corresponding satellite, and returns to step S3 to achieve wide-area search and continuous tracking of maritime targets.

[0081] Example:

[0082] The high-orbit satellites are relatively stationary above the observation area, and 15 groups of low-orbit satellites are distributed in groups of five on three orbital lines in the area. Each group of satellites includes one electronic reconnaissance observation satellite, one SAR observation satellite, and one optical observation satellite.

[0083] The method of the present invention is used to carry out multi-satellite autonomous collaborative simulation, and the observation view of the high-orbit satellite in the mission area is as follows: Figure 2 As shown, Figure 2 (a) is a global view, and (b) is a local view. Figure 3 As shown, Figure 3 (a) is the global view, and (b) is the local view. Figure 4 is the simulation result. Figure 4 It can be seen that the autonomous collaborative planning of the present invention makes full use of the observation resources of overhead low-orbit satellites, can quickly detect maritime targets over a large range in a short time, and achieve continuous and stable tracking in the subsequent process.

[0084] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea, characterized in that: The steps include: S1. The high-orbit satellite conducts preliminary observation of the set marine target area, obtains rough target information, and sends it to the ground station in real time; S2. The ground station forms an initial list of maritime target situations based on the rough target information observed by the high-orbit satellite; S3. The ground station generates a list of high and low orbit satellite observation requirements based on the maritime target situation list; S4. The ground station plans the task sequence of the satellite at the current moment according to the observation demand information of the high and low orbit satellites and sends it to the corresponding satellite. The corresponding satellite executes the task sequence and feeds back the observation results to the ground station. S5. The ground station updates the maritime target situation list according to the observation results of each corresponding satellite, and returns to step S3 to achieve wide-area search and continuous tracking of maritime targets.

2. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: The multiple satellites include a high-orbit satellite and multiple low-orbit satellites.

3. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: In step S1, the method for the high-orbit satellite to conduct preliminary observation of the set marine target area is as follows: The high-orbit satellite first calculates the number of preliminary observations based on the single observation range and the set marine target area range. a and b represent the length and width of the target area at sea. a , l b Indicates the length and width of a single observation range of a high-orbit satellite; The area of ​​each observation is planned according to the number of preliminary observations, and the set offshore target area is divided into x columns and y rows, where The distance between the center coordinates of adjacent segmented regions in each column is l a , the center coordinates of adjacent segmented regions in each row are l apart b ; The high-orbit satellite conducts a snake-like search from top to bottom for each segmented area in turn; The observation time sequence is determined according to the high-orbit satellite observation time interval constraint, and the high-orbit satellite observation time interval constraint is determined by the satellite payload maneuverability.

4. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: The situation list information includes the category, location, latest observation time, observation method, and category confidence of the observed target.

5. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: The method for obtaining the situation list information is as follows: In the target search phase, corresponding to the first round of high-orbit observation, the ground station adds the rough target information observed by the high-orbit satellite to the situation list. The rough target information includes the target position, the latest observation time, and the observation method; Mark the target category as pending confirmation and the category confidence as empty; During the target confirmation and tracking phase, the ground station receives accurate target information from low-orbit satellite observations. The accurate target information includes the category, category confidence position, heading, speed, latest observation time, and observation method of the observed target. After associating and fusion, it is updated to the situation list to make the situation list the latest information.

6. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: In step S3, the ground station generates a low-orbit satellite observation requirement list according to the marine target situation list, wherein the low-orbit satellite observation requirement list includes a target sequence number, a target position, a target observation priority, and an observation method; The target position is predicted based on the current situation list and the observation time difference T; The target observation priority λ is calculated based on the target category importance Q and the observation time difference T: Among them, α and β represent the target observation priority weight parameter and the observation time difference weight parameter respectively; Observation time difference T = current time - last observation time.

7. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: In step S3, the ground station generates a high-orbit satellite observation requirement list according to the marine target situation list, and the high-orbit satellite observation requirement list includes the position of the center point of the observation area and the priority of the observation area; Taking the single observation range of the high-orbit satellite as the reference unit, traverse the set marine target area with a step length of s. In each reference unit, calculate the sum of the target observation priorities of all targets as the observation priority of the corresponding reference unit; All benchmark units are added as observation areas to the high-orbit satellite observation requirements list.

8. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: The step length s includes the lateral step length and the longitudinal step length.

9. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 1, characterized in that: In step S4, the method for planning the mission sequence of the satellite at the current moment is as follows: According to the high-orbit satellite observation time interval constraint, check whether the high-orbit satellite can perform the observation task at the current moment. If it can, calculate the probability of each requirement in the high-orbit satellite observation requirement list being selected, and extract the requirement as the observation task at the current moment according to the probability; Select a low-orbit satellite that can perform the observation task at the current moment, and according to the low-orbit satellite observation demand list and the target observation priority order, assign the observation demand as a task to the low-orbit satellite that meets the observation conditions and whose sub-satellite point is closest to the target position.

10. The multi-satellite autonomous collaborative method for wide-area search and tracking of mobile targets at sea according to claim 9, characterized in that: The probability that the i-th demand is selected is where λ i is the target observation priority corresponding to the i-th requirement, and n is the total number of requirements in the high-orbit satellite observation requirement list.

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