Target tracking device and target tracking program

Abstract

To provide a target tracking apparatus which estimates the position of a target highly accurately.SOLUTION: A target tracking apparatus includes a communication device and a calculation device. The communication device performs communication with a plurality of observation satellites which observe targets. The calculation device executes satellite selection means, schedule setting means and estimation means. The satellite selection means selects two or more selection satellites for observing the target from the plurality of observation satellites. The schedule setting means decides an observation schedule, along which the targets are observed by each of two or more selection satellites and transmits an observation request signal which expresses the decided observation schedule to the corresponding selection satellite. The estimation means estimates a target position based on two or more kinds of high-accurate observation information observed by each of two or more selection satellites.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a target tracking device and a target tracking program.

Background Art

[0002] Methods for tracking a target, such as a flying object, have been studied. Patent Document 1 discloses a method in which each of two airplanes measures angle information from the airplane to the target using a passive sensor and estimates the position of the target in order to track the target. On the other hand, Patent Document 2 discloses a method for recognizing a target with high accuracy using infrared rays and a laser.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When tracking a target using a satellite, generally, the position of the target is specified based on observation information observed by one satellite. For this reason, it is impossible to accurately observe a position including the altitude of the target.

[0005] In view of the above situation, one of the objects is to provide a target tracking device that can accurately observe the position of a target. Other objects can be understood from the following description and the description of the embodiments.

Means for Solving the Problems

[0006] The means for solving the problem are described below using the numbers and symbols used in the embodiments for carrying out the invention. These numbers and symbols are added in parentheses for reference to show an example of the correspondence between the claims and the embodiments for carrying out the invention. Therefore, the claims should not be interpreted restrictively because of the parenthetical statements.

[0007] A target tracking device (400) according to one embodiment for achieving the above objective comprises a communication device (410) and a computing device (420). The communication device (410) is Early warning satellites that acquire wide-area observation information including targets and the aforementioned It communicates with multiple observation satellites (300) that observe the target (10). The computing unit (420) Based on the aforementioned wide-area observation information, the target is detected, and The position of the target (10) is estimated based on high-precision observation information representing information about the target (10) observed by multiple observation satellites (300). The computing unit (420) performs the following functions: target detection means, satellite selection means (502), schedule setting means (503), and estimation means (504). The target detection means obtains the wide-area observation information of the target from the early warning satellite, estimates the position of the target, and detects it. The satellite selection means (502) selects two or more selected satellites from a plurality of observation satellites (300) to observe the target (10) according to the position of the target (10). The schedule setting means (503) determines an observation schedule (510) for each of the two or more selected satellites to observe the target (10), and transmits an observation request signal representing the determined observation schedule (510) to the corresponding selected satellite among the two or more selected satellites. The estimation means (504) estimates the position of the target (10) based on two or more high-precision observation pieces of information observed by each of the two or more selected satellites, and outputs an output signal representing the estimated position of the target (10). In the observation schedule (510), the time at which the first selected satellite among the two or more selected satellites observes the target (10) is the same as the time at which the second selected satellite among the two or more selected satellites observes the target (10), and is configured independently of the plurality of observation satellites.

[0008] A target tracking program (500) according to one embodiment for achieving the above objective is provided to the computing unit (420) Target detection means, The satellite selection means (502), the schedule setting means (503), and the estimation means (504) are executed. The target detection means obtains the wide-area observation information of the target from an early warning satellite that acquires wide-area observation information including the target, estimates the position of the target, and detects it. The satellite selection means (502) selects two or more selected satellites from a plurality of observation satellites (300) to observe the target (10) according to the position of the target (10). The schedule setting means (503) determines an observation schedule (510) for each of the two or more selected satellites to observe the target (10), and transmits an observation request signal representing the determined observation schedule (510) to the corresponding selected satellite among the two or more selected satellites. The estimation means (504) estimates the position of the target (10) based on two or more high-precision observation information observed by each of the two or more selected satellites, and outputs an output signal representing the estimated position of the target (10). In the observation schedule (510), the time at which the first selected satellite among the two or more selected satellites observes the target is the same as the time at which the second selected satellite among the two or more selected satellites observes the target (10), and is a target tracking program to be executed by a computer configured independently of the plurality of observation satellites. [Effects of the Invention]

[0009] According to the above configuration, the target's position can be observed with high precision. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a target tracking system in one embodiment. [Figure 2] This is a schematic diagram of an early warning satellite in one embodiment. [Figure 3] This is a schematic diagram of the observation satellite in one embodiment. [Figure 4] This diagram shows the configuration of the observation schedule in one embodiment. [Figure 5] This is a schematic diagram of a target tracking device in one embodiment. [Figure 6] This diagram shows the configuration of a target tracking program in one embodiment. [Figure 7A] This is a flowchart illustrating the processing performed by the target tracking system in one embodiment. [Figure 7B]This is a flowchart illustrating the processing performed by the target tracking system in one embodiment. [Modes for carrying out the invention]

[0011] (Embodiment) As shown in Figure 1, a target tracking system 1000 according to one embodiment comprises an early warning satellite 100, a communication satellite 200, a plurality of observation satellites 300 such as a first observation satellite 300-1, a second observation satellite 300-2, and a third observation satellite 300-3, and a target tracking device 400. The communication satellite 200 forms a communication network and connects the early warning satellite 100, the plurality of observation satellites 300, and the target tracking device 400 so that they can communicate with each other. The communication satellite 200 forms the communication network using, for example, optical communication. Here, when the first observation satellite 300-1, the second observation satellite 300-2, and the third observation satellite 300-3 are not distinguished, they are referred to as observation satellite 300.

[0012] The target tracking system 1000 estimates the position of target 10 with high precision. For example, the early warning satellite 100 observes a relatively wide area and acquires wide-area observation information, including information representing targets 10, such as missiles or aircraft, that are within its observation range. The wide-area observation information observed by the early warning satellite 100 is transmitted to the target tracking device 400 via the communication satellite 200. The target tracking device 400 estimates the position of target 10 based on the wide-area observation information from the early warning satellite 100. To estimate the position of target 10 with higher precision, the target tracking device 400 instructs two or more observation satellites 300 to observe target 10 at the same time. Based on the instructions from the target tracking device 400, the observation satellites 300 adjust their positions so that target 10 is within a relatively narrow observation range 30, and observe target 10. The high-precision observation information observed by the observation satellites 300 is transmitted to the target tracking device 400. The target tracking device 400 estimates the position of target 10 using the principle of triangulation, based on two or more high-precision observational data acquired from two or more observation satellites 300.

[0013] As described above, the target tracking system 1000 estimates the position of the target 10 with high precision by setting an observation schedule for the observation satellite 300 to observe the target 10.

[0014] (Configuration of the target tracking system) The configuration of the target tracking system 1000 will be described. The early warning satellite 100 is arranged in a high orbit, for example, a geostationary orbit, and is configured to observe the direction where the Earth exists from the high orbit and acquire wide-area observation information including the target 10. The target 10 represents a flying object moving in a lower orbit than the early warning satellite 100, for example, a missile, an aircraft, etc. As shown in FIG. 2, the early warning satellite 100 includes a communication device 110, a computing device 120, and a wide-area observation device 130.

[0015] The communication device 110 is configured to connect to the satellite communication network 210 formed by the communication satellite 200 using wireless communication and communicate with the target tracking device 400. The communication device 110 transfers the signal acquired from the target tracking device 400 to the computing device 120. Also, it transfers the signal generated by the computing device 120 to the target tracking device 400. The communication device 110 includes various interfaces such as a transceiver that transmits and receives optical signals, for example.

[0016] The wide-area observation device 130 is configured to observe the direction where the Earth exists based on the instruction of the computing device 120 and acquire wide-area observation information. The wide-area observation device 130 observes, for example, a relatively wide area of the ground surface 20 in a fixed direction from the early warning satellite 100. By observing the ground surface 20 from the high orbit, the wide-area observation device 130 acquires wide-area observation information including information representing the position of the target 10 moving in the atmosphere or in a lower orbit. The wide-area observation device 130 is, for example, a passive sensor and includes imaging devices such as an infrared camera and a visible light camera. For example, the wide-area observation information is a wide-area imaging image obtained by imaging the direction where the Earth exists from the high orbit, and the information representing the position of the target 10 represents the area of the target 10 imaged in the wide-area imaging image.

[0017] The computing unit 120 is configured to control the wide-area observation device 130 and generate a wide-area observation signal representing the wide-area observation information acquired from the wide-area observation device 130. The generated wide-area observation signal is transmitted by the computing unit 120 to the target tracking device 400. The computing unit 120 controls the wide-area observation device 130 to periodically acquire wide-area observation information. The computing unit 120 may also control the wide-area observation device 130 to acquire wide-area observation information based on instructions from outside the early warning satellite 100, for example, from the target tracking device 400. For example, the computing unit 120 includes a central processing unit (CPU).

[0018] The observation satellite 300 is positioned in low Earth orbit, for example, at an altitude of less than 1000 km, and is configured to observe the direction in which the Earth is located from low Earth orbit and acquire high-precision observational information, including target 10. Target 10 represents an object moving in a lower Earth orbit than the observation satellite 300. The observation satellite 300 observes a relatively narrow area of ​​the Earth's surface 20 compared to the early warning satellite 100. As shown in Figure 3, the observation satellite 300 includes a communication device 310, a computing device 320, a high-precision observation device 330, and a storage device 340.

[0019] The communication device 310 is configured to connect to the satellite communication network 210 using wireless communication and to communicate with the target tracking device 400. The communication device 310 transfers signals acquired from the target tracking device 400 to the computing device 320. It also transfers signals generated by the computing device 320 to the target tracking device 400. The communication device 310 includes various interfaces, such as transceivers for sending and receiving optical signals.

[0020] The high-precision observation device 330 is configured to observe the direction in which the Earth is located and acquire high-precision observation information based on instructions from the computing device 320. The high-precision observation device 330 observes, for example, a relatively narrow area of ​​the Earth's surface 20. By observing the Earth's surface 20 from low Earth orbit, the high-precision observation device 330 acquires high-precision observation information that includes information representing the position of the target 10 moving within the atmosphere or in low Earth orbit. The high-precision observation device 330 is, for example, a passive sensor and includes imaging devices such as an infrared camera and a visible light camera. For example, the high-precision observation information is a high-precision image taken from low Earth orbit in the direction in which the Earth is located, and the information representing the position of the target 10 represents the area of ​​the target 10 captured in the high-precision image.

[0021] The high-precision observation device 330 is equipped with an actuator for adjusting the observation direction. Based on instructions from the calculation device 320, the high-precision observation device 330 drives the actuator to observe the specified observation direction and acquire high-precision observation information.

[0022] The memory device 340 is configured to store various data, such as observation schedules 510, for the arithmetic unit 320 to control the high-precision observation device 330. The observation schedule 510 is provided for each observation satellite 300 and represents the time and position observed by the high-precision observation device 330 of the corresponding observation satellite 300.

[0023] The observation schedule 510 represents, for example, the observation time, the observation position, and the target number, as shown in Figure 4. The observation time represents the time observed by the high-precision observation instrument 330 of the corresponding observation satellite 300. The observation position represents the position observed by the high-precision observation instrument 330 of the corresponding observation satellite 300, such as latitude and longitude. The target number represents the identifier of the target 10 observed by the high-precision observation instrument 330 of the corresponding observation satellite 300. For example, if the high-precision observation instrument 330 is an imaging device such as an infrared camera, the observation schedule 510 represents that the high-precision observation instrument 330 will image the area including the position shown in the observation position at the time shown in the observation time, and image the target 10 with the identifier shown in the target number. The observation position represents, for example, the center position of the area imaged by the high-precision observation instrument 330, and represents the position of the target 10 shown in the target number. The observation schedule 510 may be set so that one observation satellite 300 continuously observes one target 10, or it may be set so that one observation satellite 300 switches between observing multiple targets 10. For example, the observation schedule 510 may be set to observe different targets 10 at different observation times.

[0024] The computing unit 320 shown in Figure 3 is configured to control the high-precision observation device 330 and generate high-precision observation signals that represent high-precision observation information acquired from the high-precision observation device 330. The computing unit 320 controls the high-precision observation device 330 based on the observation schedule 510. For example, the computing unit 320 acquires the position and attitude of the observation satellite 300 on which the computing unit 320 is mounted. Based on the acquired position and attitude, the computing unit 320 identifies the observation direction of the high-precision observation device 330 in order to observe the observation position expressed in the observation schedule 510, and controls the high-precision observation device 330 to observe the identified observation direction. The computing unit 320 generates high-precision observation signals that represent the high-precision observation information acquired from the high-precision observation device 330. The generated high-precision observation signals are transmitted by the computing unit 320 to the target tracking device 400. For example, the computing unit 320 includes a central processing unit (CPU).

[0025] The target tracking device 400 shown in Figure 1 is located in a facility on the Earth's surface 20 and is configured to estimate the position of the target 10 by communicating with the early warning satellite 100 and the observation satellite 300 via the communication satellite 200 from the ground. As shown in Figure 5, the target tracking device 400 includes a communication device 410, a computing device 420, an input / output device 430, and a storage device 440.

[0026] The communication device 410 is configured to connect to the satellite communication network 210 using wireless communication and to communicate with the early warning satellite 100 and the observation satellite 300. The communication device 410 transfers signals acquired from the early warning satellite 100 or the observation satellite 300 to the computing device 420. It also transfers signals generated by the computing device 420 to the target tracking device 400. The communication device 410 may also communicate with other devices. The communication device 410 includes, for example, a transceiver for wireless communication with the communication satellite 200, a NIC (Network Interface Card), a USB (Universal Serial Bus), and various other interfaces.

[0027] The input / output device 430 receives information for the arithmetic unit 420 to perform processing. The input / output device 430 is also configured to output the results of the processing performed by the arithmetic unit 420. The input / output device 430 includes various input and output devices, such as a keyboard, mouse, microphone, display, speaker, and touch panel. The input / output device 430 may be omitted.

[0028] The storage device 440 is configured to store various data for estimating the location of the target 10, such as a target tracking program 500. The storage device 440 is used as a non-transitory tangible storage medium for storing the target tracking program 500. The target tracking program 500 may be provided as a computer program product recorded on a computer-readable storage medium 1, or as a computer program product downloadable from a server.

[0029] The arithmetic unit 420 is configured to perform various data processing to estimate the position of the target 10. The arithmetic unit 420 reads and executes the target tracking program 500 from the storage device 440 to estimate the position of the target 10. For example, the arithmetic unit 420 includes a central processing unit (CPU).

[0030] As shown in Figure 6, the target tracking program 500 is configured to have the arithmetic unit 420 execute a target detection means 501, a satellite selection means 502, a schedule setting means 503, and an estimation means 504. The target detection means 501 acquires wide-area observation information of the target 10 from the early warning satellite 100 and estimates the position of the target 10. The satellite selection means 502 selects two or more observation satellites 300 that will observe the target 10 based on the position of the target 10. The schedule setting means 503 sets an observation schedule 510 that represents the times when the two or more selected observation satellites 300 will observe the target 10. The estimation means 504 estimates the position of the target 10 with high accuracy based on the high-precision observation information observed by each of the two or more observation satellites 300.

[0031] (Operation of the target tracking system) The target tracking system 1000 estimates the position of the target 10 and tracks the target 10 by executing the processes shown in Figures 7A and 7B, which are the target tracking method. The processes shown in Figures 7A and 7B are started, for example, when the target tracking system 1000 is started. For example, when the target tracking device 400 shown in Figure 5 is started, the computing device 420 executes the target tracking program 500 and executes the means shown in Figure 6.

[0032] In step S110 shown in Figure 7A, the computing unit 120 of the early warning satellite 100 uses the wide-area observation device 130 to observe a relatively wide area of ​​the Earth's surface 20 from high orbit and acquire wide-area observation information. The computing unit 120 generates a wide-area observation signal representing the acquired wide-area observation information and transmits the wide-area observation signal to the computing unit 120 of the target tracking device 400 via the satellite communication network 210. For example, the wide-area observation device 130 images a relatively wide area of ​​the Earth's surface 20 and acquires a wide-area image. The computing unit 120 generates a wide-area observation signal representing the wide-area observation image and transmits the wide-area observation signal from the communication device 110 to the communication device 410 of the target tracking device 400. The wide-area observation information may include information representing the position of the early warning satellite 100 and the attitude of the early warning satellite 100 when observed by the wide-area observation device 130.

[0033] In step S120, the computing unit 420 of the target tracking device 400 determines, based on the wide-area observation signal, whether the wide-area observation information contains information representing target 10. When the computing unit 420 receives the wide-area observation signal, it extracts wide-area observation information, such as a wide-area image, from the wide-area observation signal. The computing unit 420 determines whether the extracted wide-area observation information contains information representing target 10. For example, the computing unit 420 determines that the wide-area observation information contains information representing target 10 when the wide-area image contains an area representing target 10, and determines that the wide-area observation information does not contain information representing target 10 when the wide-area image does not contain an area representing target 10. If the computing unit 420 determines that the wide-area observation information does not contain information representing target 10, the process returns to step S110, and the computing unit 120 of the early warning satellite 100 acquires the wide-area observation information. If the computing unit 420 determines that the wide-area observation information contains information representing target 10, it executes step S130.

[0034] In step S130, the computing unit 420 estimates the position of target 10 based on wide-area observation information. For example, the computing unit 420 extracts the position and attitude of the early warning satellite 100 from the wide-area observation information and identifies the area observed by the early warning satellite 100. Specifically, based on the attitude of the early warning satellite 100, the wide-area observation direction observed by the early warning satellite 100 is identified. Based on the identified wide-area observation direction and the position of the early warning satellite 100, the observed area is identified. By comparing the observed area with the position in the wide-area imaging image that includes the area representing target 10, the computing unit 420 estimates the position of target 10.

[0035] In step S140 shown in Figure 7B, the computing unit 420 selects two or more observation satellites 300 that observe target 10 based on the position of target 10 in order to estimate the position of target 10 with high accuracy. For example, the computing unit 420 selects two or more observation satellites 300 that have the longest observation period for target 10. In this case, the computing unit 420 estimates the estimated path of target 10 based on the position of target 10. For example, the computing unit 420 estimates the trajectory of target 10 by connecting line segments connecting previously acquired positions of target 10 based on wide-area observation information obtained from the early warning satellite 100 or high-precision observation information obtained from observation satellites 300. Based on the estimated trajectory of target 10, the estimated path of target 10 is estimated. When target 10 moves along the estimated path, the computing unit 420 selects two or more observation satellites 300 that have the longest observation period. Here, the selected two or more observation satellites 300 are also called selected satellites.

[0036] In step S150, the computing unit 420 generates an observation schedule 510 for each of the two or more selected satellites to observe target 10. The computing unit 420 registers the observation time, observation position, and target number in the observation schedule 510 corresponding to the selected satellite, as shown in Figure 4. The computing unit 420 registers an identifier representing target 10 to be observed in the target number field. The estimated position of target 10 is registered in the observation position field. The computing unit 420 calculates the time at which each of the selected satellites can observe the position of target 10 and registers the calculated time as the observation time. For example, the observation time is calculated based on the attitude of the selected satellite, the observation direction that the high-precision observation instrument 330 was observing immediately before, the time it takes to change the attitude of the selected satellite to image target 10, and the time it takes to change the observation direction of the high-precision observation instrument 330. The computing unit 420 generates an observation request signal representing the generated observation schedule 510. The generated observation request signal is transmitted to the corresponding selected satellite. The observation schedule 510 represented in the observation request signal may represent multiple observation times, multiple observation locations, and multiple target numbers in order to observe multiple targets 10 in sequence, as shown in Figure 4.

[0037] In step S160 shown in Figure 7B, when each of the selected satellite's computing units 320 receives an observation request signal, it stores the observation schedule 510 represented in the observation request signal in the storage device 340. Based on the stored observation schedule 510, the computing unit 320 controls the high-precision observation device 330 to acquire high-precision observation information. For example, the computing unit 320 obtains the next observation time from the observation schedule 510 shown in Figure 4. At the observation time represented in the observation schedule 510, the computing unit 320 changes the attitude of the selected satellite on which it is mounted and the observation direction of the high-precision observation device 330 so that the observation position can be observed. When the current time reaches the observation time, the computing unit 320 controls the high-precision observation device 330 to observe a relatively narrow area of ​​the Earth's surface 20 centered on the estimated position of target 10 from low Earth orbit to acquire high-precision observation information. For example, the high-precision observation device 330 images the area centered on the position of target 10 to acquire a high-precision image. As a result, each selected satellite observes target 10 at the same time. The computing unit 320 of each selected satellite generates high-precision observation signals representing the acquired high-precision observation information, such as high-precision image data, and transmits them to the computing unit 420 of the target tracking device 400. The computing unit 320 of each selected satellite may transmit multiple high-precision observation signals representing multiple high-precision image data representing multiple targets 10 at once. The high-precision observation information may include information representing the position of the selected satellite when observed by the high-precision observation device 330, the attitude of the selected satellite, and the observation direction observed by the high-precision observation device 330. The high-precision observation information may further include identifiers of the observed targets 10.

[0038] In step S170 shown in Figure 7B, when the arithmetic unit 420 of the target tracking device 400 receives high-precision observation signals from each selected satellite, it extracts high-precision observation information from the high-precision observation signals and determines whether the high-precision observation information contains information representing target 10. If the high-precision observation information does not contain information representing target 10, the arithmetic unit 420 terminates the process. For example, the arithmetic unit 420 determines whether the high-precision image contains an area representing target 10. If the high-precision image does not contain an area representing target 10, the arithmetic unit 420 determines that the high-precision imaging information does not contain information representing target 10 and terminates the process of tracking target 10. If the high-precision image contains an area representing target 10, the arithmetic unit 420 determines that the high-precision imaging information contains information representing target 10 and executes the process in step S180. Here, if the high-precision observation information acquired from two or more selected satellites contains an area representing target 10, the arithmetic unit 420 may determine that the high-precision imaging information contains information representing target 10. Furthermore, if the high-precision observation information received from at least one selected satellite does not include an area representing target 10, the computing unit 420 may determine that the high-precision imaging information does not include information representing target 10.

[0039] In step S180, the computing unit 420 estimates the position of the target 10 based on high-precision observation information acquired from two or more selected satellites. For example, the computing unit 420 extracts the position and attitude of the selected satellites and the observation direction of the high-precision observation device 330 from the high-precision observation information to identify the high-precision observation direction observed by the selected satellites. Specifically, the high-precision observation direction observed by the selected satellites is identified based on the attitude of the selected satellites and the observation direction of the high-precision observation device 330.

[0040] The computing unit 420 calculates the relative direction of target 10 with respect to the selected satellite based on the high-precision observation direction and the relative direction of target 10 in the high-precision observation information. For example, the relative direction of target 10 with respect to the selected satellite is calculated by comparing the high-precision observation direction observed by the selected satellite with the position in the high-precision image that includes the region representing target 10.

[0041] The computing unit 420 estimates the position of target 10 based on the relative directions of target 10 with respect to two or more selected satellites. For example, the computing unit 420 estimates the position of target 10 based on the positions of each selected satellite when target 10 was observed and the relative directions of target 10 with respect to each selected satellite. The position of target 10 is estimated, for example, using the principle of triangulation.

[0042] The arithmetic unit 420 outputs information representing the estimated location of target 10 as an output signal to the input / output device 430. Based on the output signal, the input / output device 430 outputs information representing the location of target 10. The user confirms the location of target 10 by seeing the information output by the input / output device 430. The arithmetic unit 420 may also output information representing the estimated location of target 10 as an output signal to other devices. For example, other devices may deal with target 10 based on the output signal.

[0043] Once the computing unit 420 estimates the position of target 10, it returns to the process of step S140 and selects two or more observation satellites 300 based on the estimated position of target 10. In this way, the process of steps S140 to S180 is repeated, allowing the target tracking system 1000 to track target 10 by estimating its position, such as latitude, longitude, and altitude, with high accuracy. Based on the highly accurate estimated position of target 10, other devices and users can then deal with target 10.

[0044] Furthermore, the target detection means 501 causes the calculation unit 420 of the target tracking device 400 to execute the processes in steps S120 and S130. The satellite selection means 502 causes the calculation unit 420 to execute the process in step S140. The schedule setting means 503 causes the calculation unit 420 to execute the process in step S150. The estimation means 504 causes the calculation unit 420 to execute the processes in steps S170 and S180.

[0045] (modified version) The observation schedule 510 shown in Figure 4 only needs to include information for the observation satellite 300 to observe the target 10 at the observation time, and may have any configuration. For example, the observation position in the observation schedule 510 may represent the observation direction observed from the observation satellite 300 at the observation time. In this case, the calculation unit 420 of the target tracking device 400 also calculates the position of the observation satellite 300 at the observation time, calculates the direction of the position of the target 10 from the calculated position of the observation satellite 300, and registers the calculated direction as the observation direction in the observation schedule 510. The calculation unit 320 of the observation satellite 300 controls the attitude of the observation satellite 300 and the high-precision observation device 330 so that they observe the observation direction represented in the observation schedule 510 at the observation time represented in the observation schedule 510.

[0046] The wide-area observation device 130 of the early warning satellite 100 shown in Figure 2 may be configured to change its observation direction. In this case, the wide-area observation information sent from the early warning satellite 100 to the target tracking device 400 includes information representing the observation direction observed by the wide-area observation device 130. In step S130 shown in Figure 7A, the computing device 420 of the target tracking device 400 identifies the area observed by the early warning satellite 100 based on the attitude of the early warning satellite 100 and the observation direction of the wide-area observation device 130. Specifically, the wide-area observation direction observed by the early warning satellite 100 is identified based on the attitude of the early warning satellite 100 and the observation direction of the wide-area observation device 130. The observed area is identified based on the identified wide-area observation direction and the position of the early warning satellite 100. By comparing the observed area with the position in the wide-area image that includes the area representing the target 10, the computing device 420 estimates the position of the target 10.

[0047] In step S140 shown in Figure 7B, the computing unit 420 may select two or more observation satellites 300 in any way, as long as it can select two or more observation satellites 300 that can simultaneously observe the target 10. For example, the computing unit 420 may select two or more observation satellites 300 that are closest to the estimated location of the target 10.

[0048] The high-precision observation instrument 330 of the observation satellite 300 shown in Figure 3 may be configured to observe a fixed direction from the observation satellite 300. In this case, in step S160 shown in Figure 7B, the calculation unit 320 of the selected satellite controls the attitude of the selected satellite so that it can observe the observation position at the observation time shown in the observation schedule 510. When the current time reaches the observation time, the calculation unit 320 controls the high-precision observation instrument 330 to acquire high-precision observation information. The acquired high-precision observation information is sent to the calculation unit 420 of the target tracking device 400. In step S180 in Figure 7B, the calculation unit 420 identifies the high-precision observation direction observed by the selected satellite based on the attitude of the selected satellite. Based on the identified high-precision observation direction and the information of the target 10 included in the high-precision observation information, the calculation unit 420 calculates the relative direction of the target 10 from the selected satellite. Based on the relative direction of the target 10 from each selected satellite and the position of each selected satellite, the calculation unit 420 estimates the position of the target 10.

[0049] The calculation unit 420 of the target tracking device 400 shown in Figure 5 only needs to be able to estimate the position of the target 10 from wide-area observation information, and wide-area observation information may be acquired from any device. For example, wide-area observation information may be acquired from a radar site located on the ground surface 20, or from an aircraft flying within the atmosphere.

[0050] The embodiments and modifications described above are examples and may be modified as long as they do not impede functionality. Furthermore, the configurations described in each embodiment and modification may be arbitrarily modified and / or combined as long as they do not impede functionality. For example, the target tracking device 400 may communicate directly with the early warning satellite 100 or the observation satellite 300 without going through the communication satellite 200.

[0051] The target tracking device described in each embodiment can be understood, for example, as follows:

[0052] The target tracking device according to the first embodiment comprises a communication device (410) and a computing device (420). The computing device (420) performs satellite selection means (502), schedule setting means (503), and estimation means (504).

[0053] The scheduling means (503) determines an observation schedule (510) for two or more selected satellites to observe the target (10) at the same time. The estimation means (504) estimates the position of the target (10) based on high-precision observation information observed by two or more selected satellites. As a result, the target tracking device (400) can estimate the position of the target (10) with high precision.

[0054] The target tracking device according to the second embodiment is the target tracking device according to the first embodiment, wherein the satellite selection means (502) is configured to select two or more target satellites based on the movement path of the target (10).

[0055] The target tracking device according to the third embodiment is the target tracking device according to the second embodiment, wherein the satellite selection means (502) is configured to select two or more selected satellites with relatively long observation periods based on the movement path of the target (10).

[0056] This allows the same observation satellite (300) to observe the target (10) over a long period, thereby reducing the impact of measurement errors, such as errors in the position of the observation satellite (300) and errors in the direction of observation.

[0057] The target tracking device according to the fourth embodiment is the target tracking device according to the first embodiment, wherein the target (10) observed at the first time shown in the observation schedule (510) is different from the target (10) observed at the second time.

[0058] As a result, one observation satellite (300) observes multiple targets (10), allowing the target tracking device to simultaneously estimate the positions of multiple targets (10) within a predetermined range.

[0059] The fifth aspect of the target tracking device is the same as the first aspect of the target tracking device, wherein the estimation means (504) is configured to estimate the position of the target (10) based on the relative direction of the target (10) from each selected satellite.

[0060] This allows the target tracking device to estimate the position of the target (10), including its altitude.

[0061] The target tracking program according to the sixth embodiment causes the computing device (420) to execute satellite selection means (502), schedule setting means (503), and estimation means (504).

[0062] The scheduling means (503) determines an observation schedule (510) for two or more selected satellites to observe the target (10) at the same time. The estimation means (504) estimates the position of the target (10) based on high-precision observation information observed by two or more selected satellites. As a result, the computing device (420) can estimate the position of the target (10) with high precision. [Explanation of symbols]

[0063] 1:Storage medium 10: Goal 20: Ground surface 30: Observation range 100: Early warning satellite 110: Communication device 120: Arithmetic device 130: Wide-area observation equipment 200: Communications satellite 210: Satellite communication network 300: Observation satellite 310: Communication device 320: Arithmetic device 330: High-precision observation equipment 340 :Storage device 400: Target tracking device 410: Communication equipment 420: Arithmetic device 430: Input / Output Device 440 :Storage device 500: Goal Tracking Program 501: Target detection means 502: Satellite Selection Method 503: Schedule setting method 504: Estimation means 510: Observation Schedule 1000: Target Tracking System

Claims

1. An early warning satellite that acquires wide-area observation information including a target, and a communication device that communicates with a plurality of observation satellites that observe the target, A computing device that detects the target based on the wide-area observation information and estimates the position of the target based on high-precision observation information representing information about the target observed by the multiple observation satellites, Equipped with, The aforementioned computing device is A target detection means that acquires the wide-area observation information of the target from the early warning satellite, estimates the position of the target, and detects it. A satellite selection means that selects two or more selected satellites from the plurality of observation satellites to observe the target, according to the position of the target. A schedule setting means that determines an observation schedule for each of the two or more selected satellites to observe the target, and transmits an observation request signal representing the determined observation schedule to the corresponding selected satellite among the two or more selected satellites, Estimation means that estimates the position of the target based on two or more high-precision observation information observed by each of the two or more selected satellites, and outputs an output signal representing the estimated position of the target, Execute, In the observation schedule described above, the time at which the first selected satellite among the two or more selected satellites observes the target is the same as the time at which the second selected satellite among the two or more selected satellites observes the target. It is configured independently of the multiple observation satellites, Target tracking device.

2. The satellite selection means is The movement path of the aforementioned target is estimated, Based on the estimated movement path, select the two or more satellites. The target tracking device according to claim 1.

3. The satellite selection means is Based on the aforementioned movement path, the observation period during which the multiple observation satellites can observe the target is calculated. From the aforementioned plurality of observation satellites, select two or more satellites that have a relatively long observation period. The target tracking device according to claim 2.

4. The aforementioned observation schedule represents multiple observation times and the observation locations to be observed at each of the multiple observation times. The target observed at the first observation time among the multiple observation times is different from the target observed at the second observation time among the multiple observation times. A target tracking device according to any one of claims 1 to 3.

5. The estimation means is, Based on the attitude of the selected satellite when the target was observed, the high-precision observation direction observed from the selected satellite is calculated. Based on the high-precision observation direction and the target information included in the high-precision observation information, the relative direction of the target is calculated from each of the selected satellites. Based on the relative direction and the positions of each of the selected satellites, the position of the target is estimated. A target tracking device according to any one of claims 1 to 4.

6. A target detection means that acquires wide-area observation information of a target from an early warning satellite that acquires wide-area observation information including a target, and estimates and detects the position of the target, A satellite selection means that selects two or more satellites from a plurality of observation satellites to observe the target, depending on the position of the target to be observed. A schedule setting means that determines an observation schedule for each of the two or more selected satellites to observe the target, and transmits an observation request signal representing the determined observation schedule to the corresponding selected satellite among the two or more selected satellites, Estimation means that estimates the position of the target based on two or more high-precision observational data observed by each of the two or more selected satellites, and outputs an output signal representing the estimated position of the target, The computing unit is made to execute this, In the observation schedule described above, the time at which the first selected satellite among the two or more selected satellites observes the target is the same as the time at which the second selected satellite among the two or more selected satellites observes the target. To run on a computer configured independently of multiple observation satellites Goal tracking program.

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