Satellite device, radiowave source localization system, radiowave source localization method, and computer program

Abstract

This satellite device comprises: a radiowave reception unit that receives a radiowave signal from a radiowave transmission source; an acquisition unit that acquires location information indicating the location of a host satellite device when the radiowave signal is received and time information indicating the time of receiving the radiowave signal; a communication unit that communicates with two or more other satellite devices and receives from the other satellite devices that have received the radiowave signal, the pieces of location information and the pieces of time information at the time; an arrival time difference calculation unit that calculates an arrival time difference of the radiowave signals between the host satellite device and each of the other satellite devices on the basis of each time indicated by each of the pieces of time information; a radiowave source localization unit that identifies the location of the radiowave transmission source by using the arrival time difference and each of the pieces of location information; and an output unit that outputs output information including the identified position.

Description

Satellite device, radio wave source position calibration system, radio wave source position calibration method, and computer program

[0001] The present disclosure relates to a satellite device, a radio wave source position calibration system, a radio wave source position calibration method, and a computer program.

[0002] Techniques for identifying the position of an unknown radio wave transmitter on the ground are known. For example, as described in Patent Document 1, as a method for identifying the position of a radio wave transmitter, each of three satellite devices receives a radio wave signal transmitted from the radio wave transmitter and transmits data of the received radio wave signal to a ground station. The radio wave source position calibration device at the ground station identifies the position of the radio wave transmitter based on the time difference of arrival (TDOA: Time Difference of Arrival) and the instantaneous frequency difference (FDOA: Frequency Difference of Arrival) of the radio wave signals arriving at the respective satellite devices.

[0003] WO 2022 / 259598

[0004] In the method disclosed in Patent Document 1, since the calculation of radio wave source position calibration is performed at the ground station, the ground station needs to receive radio wave signals transmitted from three satellite devices. That is, in the method disclosed in Patent Document 1, the ground station needs to secure three lines of telemetry frequencies and prepare a large antenna. In other words, when constructing a system for performing radio wave source position calibration calculations at the ground station, large-scale equipment is required at the ground station, which has been an obstacle to introducing the system.

[0005] An object of the present disclosure is to provide a satellite device, a radio wave source position calibration system, a radio wave source position calibration method, and a computer program that can reduce the equipment burden on the ground station in identifying the position of a radio wave source.

[0006] A satellite device according to one aspect of the present disclosure includes: a radio wave receiving unit that receives radio waves from a radio wave source; an acquisition unit that acquires position information indicating the position of the satellite device at the time the radio waves were received and time information indicating the time the radio waves were received; a communication unit that communicates with two or more other satellite devices and receives the position information and time information from the other satellite devices that received the radio waves; an arrival time difference calculation unit that calculates the arrival time difference of radio waves between the satellite device and each of the other satellite devices based on the time indicated by each piece of time information; a radio wave source location determination unit that identifies the position of the radio wave source using the arrival time difference and the position information; and an output unit that outputs output information including the identified position.

[0007] A radio source location method in one aspect of the present disclosure involves a satellite device receiving a radio signal from a radio source, acquiring position information and time information indicating the position of the satellite device at the time the radio signal was received, communicating with two or more other satellite devices, receiving position information and time information from the other satellite devices that received the radio signal, calculating the arrival time difference of the radio signal between the satellite device and each of the other satellite devices based on the time indicated by each piece of time information, identifying the position of the radio source using the arrival time difference and the position information, and outputting output information including the identified position.

[0008] A computer program according to one aspect of the present disclosure causes a computer mounted on a satellite device to perform the following processes: acquiring a radio signal received from a radio source; acquiring position information and time information indicating the position of the satellite device at the time the radio signal was received; communicating with two or more other satellite devices and receiving position information and time information from the other satellite devices that received the radio signal at that time; calculating the difference in arrival time of the radio signal between the satellite device and each of the other satellite devices based on the time indicated by each piece of time information; identifying the position of the radio source using the difference in arrival time and the position information; and outputting output information including the identified position.

[0009] According to this disclosure, it is possible to provide a satellite device, a radio source location system, a radio source location method, and a computer program that can reduce the equipment burden on ground stations when determining the location of radio wave sources.

[0010] This is a conceptual diagram illustrating the radio source location system in this disclosure. This is a block diagram illustrating an example of the configuration of the radio source location system in this disclosure. This is a flowchart illustrating an example of the operation of a sub-satellite device in this disclosure. This is a flowchart illustrating an example of the operation of a parent satellite device in this disclosure. This is a block diagram illustrating an example of the configuration of the radio source location system in this disclosure. This is a flowchart illustrating an example of the operation of a parent satellite device in this disclosure. This is a flowchart illustrating an example of the operation of a sub-satellite device in this disclosure. This is a block diagram illustrating an example of the configuration of a satellite device in this disclosure. This is a flowchart illustrating an example of the operation of a satellite device in this disclosure. This is a diagram illustrating an example of a hardware configuration in which the parent satellite device in this disclosure is implemented by a computer device 90 including a processor.

[0011] The embodiments described below will be explained in detail with reference to the drawings. The embodiments described below have technically preferred limitations for carrying out the disclosure, but do not limit the scope of the invention. In all the drawings used in the description of the embodiments below, the same parts are denoted by the same reference numerals unless there is a particular reason not to. In the embodiments below, similar configurations and operations may be omitted from repeated explanations.

[0012] (First Embodiment) First, the system in the first embodiment will be described with reference to Figures 1 and 2. Figure 1 is a conceptual diagram for illustrating the radio source location system in this disclosure. Figure 2 is a block diagram showing an example of the configuration of the radio source location system in this disclosure. As shown in Figures 1 and 2, the radio source location system 1 has a sub-satellite device 70-1, a sub-satellite device 70-2, and a parent satellite device 10. In the following description, when there is no need to distinguish between sub-satellite devices 70-1 and 70-2, they will be referred to as sub-satellite device 70. Note that in Figure 1-2, the number of sub-satellite devices included in the radio source location system 1 is shown as two (sub-satellite devices 70-1 and 70-2), but this is just an example. The number of sub-satellite devices 70 included in the radio source location system 1 can be any number, as long as it is two or more.

[0013] Sub-satellite devices 70-1 and 70-2, and the parent satellite device 10 receive radio signals transmitted from an unknown radio source X. Sub-satellite devices 70-1 and 70-2, and the parent satellite device 10 also receive GPS signals from the GPS (Global Positioning System) satellite constellation.

[0014] Each satellite device is equipped with a communication unit for inter-satellite communication. Sub-satellite devices 70-1 and 70-2 link the radio signals they receive with GPS signals and transmit them to the parent satellite device 10. The parent satellite device 10 receives the radio signals transmitted from the sub-satellite devices 70. The parent satellite device 10 calculates the difference in arrival times of the radio signals received by each satellite device using correlation processing, and uses the calculated arrival time difference to identify the location of the radio wave source. The parent satellite device 10 outputs output information, including the identified location of the radio wave source, to the receiving device 80.

[0015] The receiving device 80 includes a receiving antenna 81 for receiving radio signals transmitted from the parent satellite device 10, and a receiving unit 82 for processing the received radio signals and converting them into a data format that can be displayed or saved. The receiving device 80 may be implemented by a ground station, or by a device managed by a user that requests the location of the radio wave source.

[0016] (Sub-satellite devices) Next, the configuration of the sub-satellite devices 70 will be described with reference to Figure 2. As mentioned above, the radio source positioning system 1 has two or more sub-satellite devices. Each of the sub-satellite devices 70 includes a radio wave receiving unit 71, a GPS signal receiving unit 72, and a communication unit 73.

[0017] The radio wave receiving unit 71 receives radio wave signals from the radio wave source X. The radio wave receiving unit 71 includes a broadband antenna and a receiving circuit. The broadband antenna is an antenna capable of receiving signals in a frequency band from an unknown radio wave source. The receiving circuit converts the radio wave signals captured by the broadband antenna into data that can be processed.

[0018] The GPS signal receiving unit 72 receives GPS signals when the radio wave receiving unit 71 acquires radio signals from the GPS satellite constellation. The GPS signals include position information and time information of the sub-satellite device 70. The GPS signal receiving unit 72 includes a directional antenna and a receiving circuit. The directional antenna is an antenna optimized for receiving GPS signals. The receiving circuit converts the radio wave signals captured by the directional antenna into processable data and extracts position information and time information of the sub-satellite device 70 from the converted data.

[0019] The communication unit 73 links the radio signal from the radio source X received by the radio wave receiving unit 71 with the GPS signal received by the GPS signal receiving unit 72 and transmits it to the parent satellite device 10. The communication unit 73 includes a directional antenna and a transmission circuit. The directional antenna is an antenna for transmitting data to the parent satellite device. The transmission circuit converts the data, which links the radio signal from the radio source X with the GPS signal, into a radio signal that can be transmitted to the parent satellite device 10.

[0020] In the above description, the sub-satellite device 70 was described as having three antennas, but it is not limited to this. For example, the sub-satellite device may have a single multiband antenna designed to receive all signals in the GPS signal frequency band, the expected frequency band from the radio wave source, and the frequency band used for inter-satellite communication.

[0021] (Parent Satellite System) Next, the configuration of the parent satellite system will be described with reference to Figure 2. The parent satellite system 10 includes a radio wave receiving unit 11, a GPS signal receiving unit 12, a communication unit 13, an arrival time difference calculation unit 14, a radio wave source position determination unit 15, and an output unit 16.

[0022] The radio wave receiving unit 11 receives radio wave signals from the radio wave source X. The radio wave receiving unit 11 includes a broadband antenna and a receiving circuit. The broadband antenna is an antenna capable of receiving signals across a wide frequency band from an unknown radio wave source. The receiving circuit converts the radio wave signals captured by the broadband antenna into data that can be processed.

[0023] The GPS signal receiving unit 12 receives GPS signals when the radio wave receiving unit 11 acquires radio signals from the GPS satellite constellation. The GPS signals include position information and time information of the parent satellite device 10 when it received radio signals from the radio wave source X. The GPS signal receiving unit 12 includes a directional antenna and a receiving circuit. The directional antenna is an antenna optimized for receiving GPS signals. The receiving circuit converts the radio signals captured by the directional antenna into processable data and extracts position information and time information of the child satellite device 70 from the converted data. The position information is information indicating the position of the satellite device that received the radio signal. The time information is information indicating the time of the satellite device that received the radio signal.

[0024] The communication unit 13 receives radio signals transmitted from the sub-satellite device 70. Specifically, the communication unit 13 receives the position information and time information of the sub-satellite device 70 at the time it receives radio signals from the radio source X. The communication unit 13 includes a directional antenna and a transmitting circuit. The directional antenna is an antenna for receiving data from the sub-satellite device. The receiving circuit converts the radio signals captured by the directional antenna into data that can be processed.

[0025] The arrival time difference calculation unit 14 calculates the arrival time difference (TDOA) of the radio signals of each satellite device and the sub-satellite device 70 based on the time information of each satellite device. The arrival time difference is the time difference in which the signal from the radio source X arrives at the satellite device. The arrival time difference is calculated by finding the time τ at which the correlation function (A) is at its maximum value. Equation (1) of the correlation function (A) is shown below. As shown in equation (1), the correlation function is calculated using the Fast Fourier Transform (FFT) and the Inverse Fast Fourier Transform (IFFT). S(τ) is the signal arriving at either sub-satellite device 70-1, sub-satellite device 70-2, or parent satellite device 10, and S(t+τ) is the signal arriving at a satellite device other than S(τ). The arrival time difference calculation unit 14 calculates the arrival time difference between the satellite device and the sub-satellite device 70-1, and the arrival time difference between the satellite device and the sub-satellite device 70-2, using equation (1). The arrival time difference calculation unit 14 may also calculate the arrival time difference for other pairs of satellite devices.

[0026]

[0027] The radio source positioning unit 15 uses the arrival time difference calculated by the arrival time difference calculation unit 14 and the position information of each satellite device to determine the position of the radio source X on the Earth's surface. The radio source positioning unit 15 uses the arrival time difference calculated by the arrival time difference calculation unit 14 to draw an equitime difference curve. The equitime difference curve is the trajectory of the point where the time difference for the signal from the radio source X to arrive at the two satellites is equal. In other words, the radio source positioning unit 15 draws a hyperbola based on the arrival time difference between its own satellite device and sub-satellite device 70-1, and a hyperbola based on the arrival time difference between its own satellite device and sub-satellite device 70-2. The intersection of the two hyperbolas is the position of the radio source. If the arrival time difference calculation unit 14 has calculated the arrival time difference for other pairs of satellites, the radio source positioning unit 15 may combine the equitime difference curves obtained from multiple pairs of satellites. This can improve the accuracy of estimating the position of the radio source. The radio source location determination unit 15 determines the coordinates of the radio source X, i.e., its latitude and longitude. In addition to latitude and longitude, the coordinates of the radio source X may also include altitude information.

[0028] The output unit 16 transmits output information, including the position of the radio wave source X on the ground surface as identified by the radio wave source location unit 15, to the receiving device 80. The output unit 16 includes a transmitting antenna and a transmitting circuit. The transmitting antenna is suitable for communication with the receiving device 80. The transmitting circuit converts the data, including the position of the radio wave source X, into a radio signal that can be received by the receiving device 80.

[0029] The output information may further include the characteristics of the interfering radio waves. These characteristics are fundamental parameters used to identify or evaluate radio waves. For example, the characteristics of interfering radio waves may include information such as the intensity, frequency, polarization, and spectral characteristics of the radio waves.

[0030] (Operation) Next, the operation of the radio source positioning system 1 in this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a flowchart illustrating an example of the operation of the sub-satellite device in this disclosure. Figure 4 is a flowchart illustrating an example of the operation of the parent satellite device in this disclosure.

[0031] [Sub-satellite device] First, the operation of the sub-satellite device 70 will be explained with reference to Figure 3. Each of the sub-satellite devices 70 first receives a radio signal from an unknown radio source X by the radio wave receiving unit 71 (step S71).

[0032] Next, each GPS signal receiving unit 72 of the sub-satellite device 70 receives the GPS signal of the sub-satellite device 70 when it received the radio signal in step S71 (step S72). The received GPS signal includes location information and time information.

[0033] Next, each communication unit 73 of the child satellite device 70 links the radio signal received in step S71 with the GPS signal received in step S72 and transmits it to the parent satellite device (step S73).

[0034] [Parent Satellite Device] Next, the operation of the parent satellite device 10 will be explained with reference to Figure 4. The processing in steps S11 to S12 is the same as the processing in steps S71 to S72. The radio wave receiving unit 11 of the parent satellite device 10 receives a radio signal from an unknown radio wave source X (step S11). Next, the GPS signal receiving unit 12 receives the GPS signal of the parent satellite device 10 when it received the radio signal in step S11 (step S12). The arrival time difference calculation unit 14 links the radio signal received in step S11 with the GPS signal received in step S12 (step S13).

[0035] Next, the communication unit 13 receives the radio signal transmitted from the sub-satellite device 70 (step S14). As mentioned above, the radio signal transmitted from the sub-satellite device 70 is linked to the GPS signal of the sub-satellite device 70.

[0036] Next, the arrival time difference calculation unit 14 calculates the arrival time difference between its own satellite device and each of the sub-satellite devices using equation (1) (step S15).

[0037] Next, the radio wave source positioning unit 15 uses the arrival time difference calculated by the arrival time difference calculation unit 14 and the position information of each satellite device to identify the coordinates of the radio wave source X (step S16).

[0038] Next, the output unit 16 transmits output information, including the location of the radio wave source X identified by the radio wave source location unit 15, to the receiving device 80 (step S17). After completing the process in step S17, the radio wave source location system 1 terminates the series of processes described above.

[0039] As described above, the parent satellite device of this embodiment comprises a radio wave receiving unit, a GPS signal receiving unit, a communication unit, an arrival time difference calculation unit, a radio wave source position determination unit, and an output unit. The radio wave receiving unit receives radio waves from a radio wave source. The GPS signal receiving unit acquires position information indicating the position of the satellite device at the time of receiving the radio wave signal and time information indicating the time the radio wave signal was received. The communication unit communicates with two or more sub-satellite devices and receives position information and time information from the sub-satellite devices that received the radio wave signal. The arrival time difference calculation unit calculates the arrival time difference of radio waves between the satellite device and each of the other satellite devices based on the time indicated by each piece of time information. The radio wave source position determination unit uses the arrival time difference and each piece of position information to determine the position of the radio wave source. The output unit outputs output information including the determined position.

[0040] With the above configuration, the parent satellite device of this embodiment can reduce the equipment burden on the ground station when determining the location of the radio wave source. When determining the location of the radio wave source based on TDOA and FDOA, if calculation processing is performed at the ground station, the ground station had to receive radio wave signals transmitted from three satellite devices. In other words, when constructing a system that performs radio wave source location calculations at the ground station, large-scale equipment was required at the ground station. In the radio wave source location system of this embodiment, the parent satellite device comprises a communication unit that communicates with the child satellite devices, an arrival time difference calculation unit that performs radio wave source location calculations, and a radio wave source location location unit, and output information including the location determined by the parent satellite device is transmitted to the ground station. As a result, the ground station only needs to receive output information transmitted from one satellite device (parent satellite device), so the number of telemetry frequencies to be secured can be reduced to one line. In addition, since the amount of data to be received is reduced, the reception performance required of the ground station is also reduced. In short, the parent satellite device of this embodiment can reduce the equipment burden on the ground station when determining the location of the radio wave source.

[0041] In one embodiment of this parent satellite device, the output unit transmits output information to a ground station. The ground station is a facility managed by a user requesting information on the location of a radio wave source, and has the function of receiving output information and the function of converting the received output information into a displayable data format. As a result, the parent satellite device in one embodiment of this embodiment can shorten the time it takes to deliver data to a user requesting information on the location of a radio wave source, thereby improving the immediacy of data delivery. When calculation processing is performed at the ground station, the radio wave signals transmitted from the satellite device are aggregated at the ground station, positional calculation processing is performed, and then the data is delivered to the user requesting information on the location of the radio wave source. Therefore, in systems that perform calculation processing at the ground station, it took time to deliver data to the user requesting information on the location of a radio wave source. In contrast, the parent satellite device in one embodiment of this embodiment can deliver the data requested by the user directly to the user, thus shortening the time it takes to deliver data to the user and improving the immediacy of data delivery.

[0042] In one aspect of this embodiment, the parent satellite device acquires positional and time information of its own satellite device by receiving GPS signals from a constellation of GPS satellites. As a result, according to the parent satellite device in one aspect of this embodiment, calculation processing can be performed using accurate time and positional information, thereby improving the accuracy of identifying the location of the radio wave source.

[0043] In one embodiment of this parent satellite device, the output information includes characteristic information of the radio signal from the radio source. By including characteristic information of the radio signal in addition to the location of the radio source, the parent satellite device in one embodiment of this embodiment can provide more information about the radio source. In other words, according to the parent satellite device in one embodiment of this embodiment, information about the radio source can be obtained in more detail.

[0044] In the mother satellite device according to one aspect of the present embodiment, the characteristic information included in the output information is the intensity and frequency of the radio wave signal. By providing the intensity and frequency of the radio wave signal to the user, the user can estimate the nature and type of the radio wave source. That is, according to the mother satellite device according to one aspect of the present embodiment, the information of the radio wave source can be grasped in more detail.

[0045] (Modification) In the present embodiment, it is assumed that the position information and time information of the satellite device are obtained by receiving the GPS signal, but the present invention is not limited to this. Each satellite device may obtain the position information and time information of the satellite device by other known methods. For example, each satellite device may periodically receive high-precision orbit correction data from a ground station and calculate the current position information of the satellite using the initial position and velocity vector of the satellite. Alternatively, each satellite device may be equipped with a high-precision atomic clock, and the time of the atomic clock may be obtained as the time information of the satellite device. However, when this method is adopted, it is preferable to periodically communicate with the ground station to synchronize the time in order to obtain high-precision time information.

[0046] (Second Embodiment) Next, the radio wave source position calibration system in the present embodiment will be described with reference to the drawings. In the following description, the same reference numerals are given to the same parts as those in the first embodiment, and the description will be omitted as appropriate. The radio wave source position calibration system of the present embodiment is different from the radio wave source position calibration system of the first embodiment in that it has a function of changing the mother satellite device to another satellite device. Therefore, it is assumed that each of the satellite devices included in the radio wave source position calibration system of the second embodiment has the same hardware configuration and software configuration.

[0047] (Configuration) FIG. 5 is a block diagram showing an example of the configuration of the radio wave source position calibration system in the present disclosure. As shown in FIG. 5, the radio wave source position calibration system 2 includes a mother satellite device 20 and a child satellite device 70. The mother satellite device 20 includes a control unit 27 in addition to a radio wave reception unit 11, a GPS signal reception unit 12, a communication unit 13, an arrival time difference calculation unit 14, a radio wave source position calibration unit 15, and an output unit 16.

[0048] The control unit 27 controls whether the satellite device operates as a parent satellite device or as a child satellite device. The control unit 27 receives a control signal from the transmitting antenna 83 of the receiving device 80, which is an instruction to change the parent satellite device. The control unit 27 uses the control signal received from the receiving device 80 to perform the change of parent satellite device. Specifically, the parent satellite device 20, having received the control signal from the receiving device 80, transmits a control signal via the communication unit 13 to the child satellite device 70, which will become the new parent satellite device, instructing it to operate as a parent satellite device. The child satellite device that will become the new parent satellite device may be designated by the control signal received from the receiving device 80, or it may be designated arbitrarily by the parent satellite device. The control unit 74 of the child satellite device 70, having received the control signal, controls the device to function as a parent satellite device. When the original parent satellite device 20 transmits a control signal instructing it to operate as a parent satellite device, it is controlled by the control unit 27 to function as a child satellite device.

[0049] For example, when the parent satellite device 20 switches to the function of a child satellite device, the control unit 27 performs the following processing. First, the control unit 27 disables the functions of the arrival time difference calculation unit 14 and the radio source position determination unit 15. Also, the control unit 27 changes the control protocol of the communication unit 13 for communication with the new parent satellite device.

[0050] For example, when the child satellite device 70 switches to the functions of the parent satellite device, the control unit 74 performs the following processing. First, the control unit 74 changes the communication protocol of the communication unit 73 to one for communication with the parent satellite device 20. Also, the child satellite device 70 activates the functions of the parent satellite device, namely the arrival time difference calculation unit, the radio source position determination unit, and the output unit.

[0051] (Operation) Next, the operation of the radio source location system 1 in this embodiment will be described with reference to Figures 6 and 7. Figure 6 is a flowchart illustrating an example of the operation of the parent satellite device in this disclosure. Figure 7 is a flowchart illustrating an example of the operation of the child satellite device in this disclosure. Note that Figures 6 and 7 only show an example of the operation of changing the parent satellite device to another satellite device. In the radio source location system of the second embodiment, the location of the radio source is determined in the same manner as the example of operation shown in the first embodiment.

[0052] [Parent Satellite Device] First, the processing of the parent satellite device will be explained with reference to Figure 6. The control unit 27 receives a control signal from the receiving device 80 instructing a change to the parent satellite device (step S21).

[0053] When the communication unit 13 receives a control signal instructing the parent satellite device to be changed in step S21, it transmits a control signal to one of the child satellite devices instructing it to operate as the parent satellite device (step S22).

[0054] Next, the control unit 27 controls the satellite device to operate as a sub-satellite device (step S23). The control unit 27 disables the functions of the arrival time difference calculation unit 14 and the radio source position determination unit 15. The control unit 27 also changes the control protocol of the communication unit 13 for communication with the new parent satellite device.

[0055] [Sub-satellite device] Next, the processing of the sub-satellite device will be explained with reference to Figure 7. The communication unit 73 receives a control signal from the parent satellite device 20 instructing it to operate as the parent satellite device (step S24).

[0056] Next, the control unit 74 controls the satellite device to operate as a parent satellite device (step S25). The control unit 74 changes the communication protocol of the communication unit 73 for communication with the parent satellite device 20. The child satellite device 70 also activates the functions of the parent satellite device, namely the arrival time difference calculation unit, the radio source position determination unit, and the output unit.

[0057] The radio source location system of this embodiment is configured as described above. In addition to the effects obtained from the radio source location system of the first embodiment, the radio source location system of this embodiment obtains the following effects.

[0058] One aspect of this embodiment of the parent satellite device further includes a control unit that controls whether the satellite device operates as a parent satellite device or as a child satellite device. When the satellite device operates as a child satellite device, the communication unit transmits a control signal to one of the other satellite devices instructing it to operate as a parent satellite device. According to one aspect of this embodiment of the parent satellite device, for example, if an abnormality is detected in the parent satellite device or if the power level of the parent satellite device drops, another satellite device can be changed to act as the parent satellite device. This makes it possible to maintain the accuracy of radio source positioning even when an abnormality occurs. In addition, by distributing the load on the entire radio source positioning system, the lifespan of each satellite device can be extended.

[0059] (Third Embodiment) In this embodiment, a satellite device 30 is described, which has a simplified configuration compared to the parent satellite device in the first and second embodiments.

[0060] (Configuration) The configuration of the satellite device in this embodiment will be described with reference to the drawings. Figure 8 is a block diagram showing an example of the configuration of the satellite device in this disclosure. The satellite device 30 includes a radio wave receiving unit 31, an acquisition unit 32, a communication unit 33, an arrival time difference calculation unit 34, a radio wave source position determination unit 35, and an output unit 36.

[0061] The radio wave receiving unit 31 receives radio wave signals from a radio wave source. The acquisition unit 32 acquires position information indicating the position of the satellite device at the time the radio wave signal was received, and time information indicating the time the radio wave signal was received. The communication unit 33 communicates with two or more other satellite devices and receives position information and time information from the other satellite devices that received the radio wave signal. The arrival time difference calculation unit 34 calculates the arrival time difference of the radio wave signals between the satellite device and each of the other satellite devices based on the time indicated by each piece of time information. The radio wave source position determination unit 35 identifies the position of the radio wave source using the arrival time difference and each piece of position information. The output unit 36 ​​outputs output information including the identified position.

[0062] (Operation) Next, an example of the operation of the satellite device in this embodiment will be described with reference to Figure 9. Figure 9 is a diagram showing an example of the operation of the satellite device in this disclosure.

[0063] First, the radio wave receiving unit 31 receives a radio wave signal from the radio wave source (step S31).

[0064] Next, the acquisition unit 32 acquires position information indicating the position of the satellite device when it received the radio signal, and time information indicating the time when the radio signal was received (step S32).

[0065] Next, the communication unit 33 communicates with two or more other satellite devices and receives location information and time information from the other satellite devices that received the radio signal (step S33).

[0066] Next, the arrival time difference calculation unit 34 calculates the arrival time difference between its own satellite device and each of the other satellite devices based on the time indicated by each time information (step S34).

[0067] Next, the radio wave source location determination unit 35 determines the location of the radio wave source using the arrival time difference and the location information (step S35).

[0068] Next, the output unit 36 ​​outputs output information including the specified location (step S36).

[0069] The satellite device of this embodiment communicates with other satellite devices, receives location and time information from the other satellite devices that received the radio signal, uses this information to identify the location of the radio wave source, and outputs output information including the identified location of the radio wave source. When calculation processing is performed at a ground station, it was necessary to secure three telemetry lines, but with the satellite device of this embodiment, it is sufficient to secure one telemetry line. In addition, the amount of data received by the ground station is reduced compared to when calculation processing is performed at the ground station. In other words, with the parent satellite device of this embodiment, the equipment burden on the ground station can be reduced when identifying the location of the radio wave source.

[0070] (Hardware Configuration) Each component in each embodiment of the present disclosure described above can, of course, be implemented as hardware, but can also be implemented by a computer device or firmware based on program control.

[0071] Figure 10 shows an example of a hardware configuration in which the parent satellite device in this disclosure is implemented by a computer device 90 including a processor. The parent satellite device (or satellite device) in each embodiment is implemented by the computer device 90. As shown in Figure 10, the computer device 90 includes a processor 91, memory 92, a storage device 93 such as a hard disk for storing programs, an input / output interface 94 for connecting input and output devices, and a communication interface 95 for network connection.

[0072] The processor 91 loads a program (instruction) stored in the storage device 93 or the like into the memory 92. For example, the program is a software program for executing the control and processing described in this disclosure. The processor 91 executes the program loaded into the memory 92. By executing the program, the processor 91 executes the control and processing described in this disclosure.

[0073] The storage device 93 is, for example, an optical disk, a flexible disk, a magneto-optical disk, an external hard disk, or a semiconductor memory. Some of the storage media of the storage device are non-volatile storage devices, and programs are recorded therein. Alternatively, programs may be downloaded from an external computer (not shown) connected to a communication network.

[0074] The input devices connected to the input / output interface 94 are implemented by, for example, a mouse or keyboard, and are used for input operations. Similarly, the output devices connected to the input / output interface 94 are implemented by, for example, a display, and are used for displaying and confirming the output results.

[0075] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure can be made as can be understood by those skilled in the art within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0076] Some or all of the above embodiments may also be described as follows: (Note 1) A satellite device comprising: radio wave receiving means for receiving radio waves from a radio wave source; acquisition means for acquiring position information indicating the position of the satellite device at the time the radio wave signal was received and time information indicating the time the radio wave signal was received; communication means for communicating with two or more other satellite devices and receiving the position information and time information at that time from the other satellite devices that received the radio wave signal; arrival time difference calculation means for calculating the arrival time difference of the radio waves between the satellite device and each of the other satellite devices based on the time indicated by each of the time information; radio wave source positioning means for identifying the position of the radio wave source using the arrival time difference and each of the position information; and output means for outputting output information including the identified position. (Note 2) The satellite device according to Note 1, wherein the output means transmits the output information to a ground station. (Note 3) The satellite device according to Note 1 or 2, wherein the ground station is a facility managed by a user requesting location information of the radio wave source, and has a function to receive the output information and a function to convert the received output information into a displayable data format. (Note 4) The satellite device according to any one of Notes 1 to 3, wherein the acquisition means acquires the location information and time information of the satellite device by receiving GPS signals from a GPS (Global Positioning System) satellite constellation. (Note 5) The satellite device according to any one of Notes 1 to 4, wherein the output information includes characteristic information of the radio wave signal from the radio wave source. (Note 6) The satellite device according to Note 5, wherein the characteristic information is the intensity and frequency of the radio wave signal. (Note 7) The satellite device according to any one of Notes 1 to 6, wherein the self-satellite device is a parent satellite device, and the other satellite devices are child satellite devices, and further comprises control means for controlling whether the self-satellite device operates as the parent satellite device or as a child satellite device, and when the self-satellite device operates as a child satellite device, the communication means transmits a control signal to one of the other satellite devices instructing it to operate as the parent satellite device.(Note 8) A radio source location system having a satellite device as described in any one of Notes 1 to 7, and two or more sub-satellite devices, each having: a radio wave receiving means for receiving the radio wave signal; an acquisition means for acquiring the position information and time information of the self-satellite device when the radio wave signal was received; and a communication means for transmitting the position information and time information of the self-satellite device that received the radio wave signal to the satellite device. (Note 9) A radio source location method comprising: a satellite device receiving a radio wave signal from a radio wave source, acquiring the position information and time information of the self-satellite device, communicating with two or more other satellite devices when the radio wave signal was received, receiving the position information and time information from the other satellite devices at that time, calculating the difference in arrival time of the radio wave signal between the self-satellite device and each of the other satellite devices based on the time indicated by each of the time information, identifying the position of the radio wave source using the difference in arrival time and each of the position information, and outputting output information including the identified position. (Note 10) A computer program that causes a computer mounted on a satellite device to execute the following: a process of acquiring a radio signal received from a radio signal source; a process of acquiring position information indicating the position of the satellite device at the time the radio signal was received and time information indicating the time the radio signal was received; a process of communicating with two or more other satellite devices and receiving the position information and time information at that time from the other satellite devices that received the radio signal; a process of calculating the difference in arrival time of the radio signal between the satellite device and each of the other satellite devices based on the time indicated by each of the time information; a process of identifying the position of the radio signal source using the difference in arrival time and each of the position information; and a process of outputting output information including the identified position.

[0077] Furthermore, in the above appendices, some or all of the configurations described in Appendices 2 to 7, which are subordinate to Appendice 1, may also be subordinate to Appendices 9 and 10 in the same way as those described in Appendices 2 to 7. Moreover, not limited to Appendices 1, 9, and 10, some or all of the configurations described as appendices may also be subordinate to various hardware, software, various recording means for recording software, or systems, without departing from the embodiments described above.

[0078] This application claims priority based on Japanese Patent Application No. 2024-162044, filed on 19 September 2024, and incorporates all of its disclosures herein.

[0079] 1, 2 Radio source location system 10, 20 Parent satellite device 30 Satellite device 11, 31 Radio wave receiving unit 12 GPS signal receiving unit 32 Acquisition unit 13, 33 Communication unit 14, 34 Arrival time difference calculation unit 15, 35 Radio source location location unit 16, 36 Output unit 27 Control unit 70 Sub-satellite device 71 Radio wave receiving unit 72 GPS signal receiving unit 73 Communication unit 74 Control unit 80 Receiving device 81 Receiving antenna 82 Receiving unit 83 Transmitting antenna 90 Computer device 91 Processor 92 Memory 93 Storage device 94 Input / output interface 95 Communication interface

Claims

1. A satellite device comprising: radio wave receiving means for receiving radio wave signals from a radio wave source; acquisition means for acquiring position information indicating the position of the satellite device at the time the radio wave signal was received and time information indicating the time the radio wave signal was received; communication means for communicating with two or more other satellite devices and receiving the position information and time information at that time from the other satellite devices that received the radio wave signal; arrival time difference calculation means for calculating the arrival time difference of the radio wave signal between the satellite device and each of the other satellite devices based on the time indicated by each of the time information; radio wave source positioning means for identifying the position of the radio wave source using the arrival time difference and each of the position information; and output means for outputting output information including the identified position.

2. The satellite device according to claim 1, wherein the output means transmits the output information to a ground station.

3. The satellite apparatus according to claim 2, wherein the ground station is a facility managed by a user requesting information on the location of the radio wave source, and has a function to receive the output information and a function to convert the received output information into a displayable data format.

4. The satellite device according to claim 1, wherein the acquisition means acquires the position information and time information of the satellite device by receiving GPS signals from a constellation of GPS (Global Positioning System) satellites.

5. The satellite apparatus according to claim 1, wherein the output information includes characteristic information of the radio signal from the radio wave source.

6. The satellite device according to claim 5, wherein the characteristic information is the intensity and frequency of the radio signal.

7. The satellite device according to claim 1, wherein the self-satellite device is a parent satellite device, and the other satellite devices are child satellite devices, and further comprising control means for controlling whether the self-satellite device operates as the parent satellite device or as a child satellite device, and when the self-satellite device operates as a child satellite device, the communication means transmits a control signal to one of the other satellite devices instructing it to operate as the parent satellite device.

8. A radio source positioning system comprising a satellite device according to any one of claims 1 to 7, and two or more sub-satellite devices each having: a radio wave receiving means for receiving the radio wave signal; an acquisition means for acquiring the position information and time information of the satellite device when it receives the radio wave signal; and a communication means for transmitting the position information and time information of the satellite device when it receives the radio wave signal to the satellite device.

9. A method for determining the location of a radio source, comprising: a satellite device receiving a radio signal from a radio source; acquiring location information indicating the position of the satellite device at the time of receiving the radio signal and time information indicating the time the radio signal was received; communicating with two or more other satellite devices and receiving the location information and time information from the other satellite devices that received the radio signal; calculating the difference in arrival time of the radio signal between the satellite device and each of the other satellite devices based on the time indicated by each of the time information; identifying the location of the radio source using the difference in arrival time and each of the location information; and outputting output information including the identified location.

10. A computer program that causes a computer mounted on a satellite device to execute the following: a process for acquiring a radio signal received from a radio signal source; a process for acquiring position information indicating the position of the satellite device at the time the radio signal was received and time information indicating the time the radio signal was received; a process for communicating with two or more other satellite devices and receiving the position information and time information at that time from the other satellite devices that received the radio signal; a process for calculating the difference in arrival time of the radio signal between the satellite device and each of the other satellite devices based on the time indicated by each of the time information; a process for identifying the position of the radio signal source using the difference in arrival time and each of the position information; and a process for outputting output information including the identified position.

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