LEO satellite, LEO satellite system, and control method

Abstract

A LEO satellite (10) is provided with: a light-projecting element (11) that emits an outgoing beam to another LEO satellite (10); an optical telescope (12); an optical phased array (13); a light-receiving element (14) that receives an incoming beam from another LEO satellite (10); a ranging unit (15) that measures the distance to another LEO satellite (10) on the basis of at least one of an outgoing beam and incoming beam; and a control unit (16). The control unit (16) performs outgoing beam scanning, which uses the optical telescope (12), with respect to another LEO satellite (10) on the same orbital plane so as to capture the other LEO satellite (10) and receive an incoming beam from the other LEO satellite (10), and performs outgoing beam scanning, which uses the optical phased array (13), with respect to another LEO satellite (10) on a different orbital plane so as to capture the other LEO satellite (10) and receive an incoming beam from the other LEO satellite (10).

Description

[Technical field]

[0001] The present disclosure relates to a Low Earth Orbit (LEO) satellite, a LEO satellite system, and a control method. [Background technology]

[0002] In recent years, application technologies related to LEO satellites that make up a LEO satellite constellation have been developed. For example, Patent Document 1 discloses a technology for measuring the distance between LEO satellites by wirelessly transmitting and receiving ranging signals between the LEO satellites. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 036328 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique disclosed in Patent Document 1 has a problem in that it is necessary to add distance measuring equipment to the LEO satellites because distance measuring signals are transmitted and received wirelessly between the LEO satellites.

[0005] Therefore, an object of the present disclosure is to solve the above-mentioned problems and provide a LEO satellite, a LEO satellite system, and a control method that can measure the distance between LEO satellites without adding ranging equipment to the LEO satellites. [Means for solving the problem]

[0006] According to one aspect, a LEO satellite includes: A LEO (Low Earth Orbit) satellite constellation, a light-projecting element that emits laser light as an emission light to another LEO satellite that constitutes the LEO satellite constellation; Optical telescopes, An optical phased array; a light receiving element that receives the laser light from the other LEO satellite as incident light; a distance measuring unit that measures a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; a control unit for controlling the light emitting element and the light receiving element, The control unit is With respect to the other LEO satellite in the same orbital plane as the LEO satellite, the outgoing light emitted from the light-projecting element is scanned using the optical telescope to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light-receiving element; For the other LEO satellite in a different orbital plane from the LEO satellite, the optical phased array is used to scan the emitted light emitted from the light-emitting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light-receiving element.

[0007] According to one aspect, a LEO satellite system includes: It is equipped with multiple LEO (Low Earth Orbit) satellites that make up the LEO satellite constellation, each of the plurality of LEO satellites; a light-projecting element that emits laser light as an emission light to another LEO satellite that constitutes the LEO satellite constellation; Optical telescopes, An optical phased array; a light receiving element that receives the laser light from the other LEO satellite as incident light; a distance measuring unit that measures a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; a control unit for controlling the light emitting element and the light receiving element, The control unit is With respect to the other LEO satellite in the same orbital plane as the LEO satellite, the outgoing light emitted from the light-projecting element is scanned using the optical telescope to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light-receiving element; For the other LEO satellite in a different orbital plane from the LEO satellite, the optical phased array is used to scan the emitted light emitted from the light-emitting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light-receiving element.

[0008] A control method according to one aspect includes: A method for controlling a LEO (Low Earth Orbit) satellite constellation, comprising: emitting laser light as an emission light to another LEO satellite constellation by a light emitting element; receiving, by a light receiving element, a laser beam from the other LEO satellite as incident light; measuring a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; A control step of controlling the light emitting element and the light receiving element, In the control step, With respect to the other LEO satellite in the same orbital plane as the LEO satellite, an optical telescope is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element; For the other LEO satellite in a different orbital plane from the LEO satellite, an optical phased array is used to scan the emitted light emitted from the light-emitting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light-receiving element. Effect of the Invention

[0009] According to the above-described aspects, it is possible to provide a LEO satellite, a LEO satellite system, and a control method that can measure the distance between LEO satellites without adding distance measuring equipment to the LEO satellites. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of the overall configuration of a LEO satellite system according to an embodiment. [Diagram 2] 1 is a block diagram showing an example of the configuration of a LEO satellite according to an embodiment. [Diagram 3] 3A to 3C are diagrams for explaining the principle of a reflection type distance measuring method in a distance measuring section according to an embodiment. [Figure 4] 4A and 4B are diagrams for explaining the principle of a pulse propagation method in a distance measuring unit according to an embodiment. [Diagram 5] 4A to 4C are diagrams for explaining the principle of a phase difference distance measuring method in a distance measuring section according to an embodiment. [Figure 6] 3A to 3C are diagrams illustrating the principle of triangulation in a distance measuring section according to an embodiment. [Figure 7] 1A and 1B are diagrams for explaining the principle of a two-way transmission and reception distance measuring method in a distance measuring section according to an embodiment. [Figure 8] 11 is a diagram illustrating an example of an operation performed by a control unit according to an embodiment when capturing another LEO satellite in the same orbital plane. FIG. [Figure 9] 10A to 10C are diagrams illustrating an example of an operation performed by a control unit according to an embodiment when capturing another LEO satellite in a different orbital plane. [Figure 10] 1 is a flow diagram illustrating an example of an operational flow when a LEO satellite according to an embodiment measures a distance to another LEO satellite. [Figure 11] FIG. 2 is a diagram illustrating an example of the hardware configuration of a computer that realizes some or all of the processing of a LEO satellite according to an embodiment. [Figure 12] FIG. 13 is a diagram illustrating an example of the configuration of a millimeter wave sensor in a LEO satellite according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that the following description and drawings are omitted and simplified as appropriate for clarity of explanation. In addition, in each of the following drawings, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary.

[0012] <Embodiment Mode> <Configuration of the embodiment> First, an example of the overall configuration of a LEO satellite system according to this embodiment will be described with reference to Fig. 1. As shown in Fig. 1, the LEO satellite system according to this embodiment includes LEO satellites 10-1 to 10-5 that make up a LEO satellite constellation. In Fig. 1, it is assumed that LEO satellites 10-1 to 10-4 move in the same orbital plane, and LEO satellite 10-5 moves in a different orbital plane from LEO satellites 10-1 to 10-4.

[0013] Hereinafter, when the LEO satellites 10-1 to 10-5 are mentioned without any particular distinction, they may be simply referred to as "LEO satellites 10." Also, in FIG. 1, five LEO satellites 10-1 to 10-5 are provided, but the number of LEO satellites 10 may be two or more.

[0014] In this embodiment, as described later, distributed MIMO (Multiple Input Multiple Output) can be realized by utilizing antennas (not shown) provided on the LEO satellites 10-1 to 10-5. Therefore, each of the LEO satellites 10-1 to 10-5 can perform distributed MIMO communication with the terminal 21, the aircraft 22, the parabolic antenna 23, etc.

[0015] Next, a configuration example of LEO satellite 10 according to the present embodiment will be described with reference to Fig. 2. Note that Fig. 2 shows a configuration example of LEO satellite 10-1, but other LEO satellites 10-2 to 10-5 have the same configuration as LEO satellite 10-1.

[0016] 2, the LEO satellite 10-1 according to this embodiment includes a light projecting element 11, an optical telescope 12, an optical phased array 13, a light receiving element 14, a ranging unit 15, and a control unit 16. Note that only components related to ranging in the LEO satellite 10-1 are shown in FIG. 2, and other components are omitted from the illustration.

[0017] The light emitting element 11 emits laser light as outgoing light to other LEO satellites 10 that make up the LEO satellite constellation.

[0018] Optical telescope 12 is used to capture other LEO satellites 10 in the same orbital plane as LEO satellite 10-1. The optical phased array 13 is used to capture other LEO satellites 10 in different orbital planes than the LEO satellite 10-1. The control unit 16 controls the light emitting element 11 and the light receiving element 14, and captures other LEO satellites 10 using the optical telescope 12 or the optical phased array 13. The optical telescope 12, the optical phased array 13, and the control unit 16 will be described in detail later.

[0019] The light receiving element 14 receives as incident light laser light from another LEO satellite 10. The incident light is, for example, laser light (reflected light) that is emitted from the light projecting element 11 and reflected by another LEO satellite 10, laser light emitted from the light projecting element 11 of the other LEO satellite 10, etc.

[0020] Distance measurement unit 15 measures the distance from LEO satellite 10-1 to the other LEO satellites 10 based on at least one of the outgoing light emitted from light projecting element 11 and the incident light received by light receiving element .

[0021] <Operation of the embodiment> Next, the operation of the LEO satellite system according to this embodiment will be described. First, an example of a ranging method in the ranging unit 15 will be described. The ranging unit 15 may measure the distance using any ranging method from among the ranging methods described below. Below, an example will be described in which the ranging unit 15 of the LEO satellite 10-1 measures the distance to the LEO satellite 10-2 in the same orbital plane. However, the ranging method described below can also be applied to a case in which the ranging unit 15 of the LEO satellite 10-1 measures the distance to the LEO satellite 10-5 in a different orbital plane.

[0022] (1) Reflective distance measurement method First, the reflection type distance measurement method will be described. 3, in the reflection-type distance measurement method, LEO satellite 10-1 emits outgoing light to LEO satellite 10-2 and receives light reflected by LEO satellite 10-2. Then, distance measurement unit 15 of LEO satellite 10-1 measures the distance from LEO satellite 10-1 to LEO satellite 10-2 based on at least one of the emitted light and the reflected light.

[0023] Reflection-type distance measurement methods include, for example, a pulse propagation method, a phase difference distance measurement method, and a triangulation method. Each of the distance measurement methods will be described below.

[0024] (1-1) Pulse propagation method First, the pulse propagation method will be described with reference to FIG. As shown in Fig. 4, in the pulse propagation method, the emitted light is a rectangular wave with a constant pulse width. Distance measurement unit 15 of LEO satellite 10-1 measures the time t from when the pulse is emitted as the emitted light to when the pulse is received as the reflected light. Then, distance measurement unit 15 of LEO satellite 10-1 calculates the distance L from LEO satellite 10-1 to LEO satellite 10-2 using the speed of light c with the following formula: L=ct / 2

[0025] Therefore, in the pulse propagation method, the LEO satellite 10-1 needs a clock for measuring the time t. A highly accurate atomic clock is suitable as the clock provided in the LEO satellite 10-1.

[0026] (1-2) Phase difference distance method Next, the phase difference distance method will be described with reference to FIG. 5, in the phase difference ranging method, the emitted light is a sine wave. The phase difference between the emitted light and the reflected light varies depending on the distance L from LEO satellite 10-1 to LEO satellite 10-2. Therefore, distance measurement unit 15 of LEO satellite 10-1 calculates distance L based on the phase difference between the emitted light and the reflected light.

[0027] (1-3) Triangulation method Next, the triangulation method will be described with reference to FIG. As shown in Fig. 6, the light reflected by LEO satellite 10-2 is received by light receiving element 14 of LEO satellite 10-1. At this time, the position on light receiving element 14 where the reflected light is received changes depending on distance L from LEO satellite 10-1 to LEO satellite 10-2. In the example of Fig. 5, distance L differs when LEO satellite 10-2 is at position A and when it is at position B, and as a result, the position on light receiving element 14 where the reflected light is received also changes. Therefore, distance measurement unit 15 of LEO satellite 10-1 calculates distance L based on the position on light receiving element 14 where the reflected light is received.

[0028] (2) Two-way transmission and reception distance measurement method Next, a two-way transmission and reception type distance measurement method will be described. In the two-way transmission and reception distance measurement method, as shown in Fig. 7, light-projecting element 11 of LEO satellite 10-1 emits outgoing light, and the outgoing light is received by light-receiving element 14 of LEO satellite 10-2. Light-projecting element 11 of LEO satellite 10-2 also emits outgoing light, and the outgoing light is received by light-receiving element 14 of LEO satellite 10-1.

[0029] At this time, the emission time is included in the emitted light emitted by light-projecting element 11 of LEO satellite 10-2. Then, distance measurement unit 15 of LEO satellite 10-1 calculates distance L from LEO satellite 10-1 to LEO satellite 10-2 based on the emission time when light-projecting element 11 of LEO satellite 10-2 emitted the emitted light and the reception time when light-receiving element 14 of LEO satellite 10-1 received the emitted light.

[0030] Similarly, the emission time is also included in the emitted light emitted by light-projecting element 11 of LEO satellite 10-1. Then, distance measurement unit 15 of LEO satellite 10-2 calculates distance L based on the emission time when light-projecting element 11 of LEO satellite 10-1 emits the emitted light and the reception time when light-receiving element 14 of LEO satellite 10-2 receives the emitted light.

[0031] For this reason, in a two-way transmission and reception distance measurement method, the LEO satellites 10-1 and 10-2 need to have clocks. As the clocks equipped in the LEO satellites 10-1 and 10-2, highly accurate atomic clocks are suitable.

[0032] As described above, distance measurement unit 15 of LEO satellite 10-1 uses one of the distance measurement methods described above to measure the distance from LEO satellite 10-1 to the other LEO satellites 10. Distance measurement units 15 of the other LEO satellites 10-2 to 10-5 measure the distance in the same manner.

[0033] However, in any of the distance measurement methods described above, the distance measurement unit 15 needs to capture other LEO satellites 10 in order to perform distance measurement.

[0034] 8, for example, when distance measurement unit 15 of LEO satellite 10-1 measures the distance to LEO satellite 10-2 in the same orbital plane, the relative speed of LEO satellite 10-2 with respect to LEO satellite 10-1 is small. Therefore, control unit 16 of LEO satellite 10-1 can capture LEO satellite 10-2 by mechanically scanning the emitted light. Therefore, in this case, control unit 16 of LEO satellite 10-1 captures LEO satellite 10-2 by scanning the emitted light emitted from light-projecting element 11 using optical telescope 12, and causes light-receiving element 14 to receive the incident light from LEO satellite 10-2.

[0035] On the other hand, as shown in FIG. 9, for example, when the distance measurement unit 15 of the LEO satellite 10-1 measures the distance to the LEO satellite 10-5 in a different orbital plane, the relative speed of the LEO satellite 10-5 with respect to the LEO satellite 10-1 becomes large. Therefore, even if the control unit 16 of the LEO satellite 10-1 uses the optical telescope 12, the control unit 16 cannot capture the LEO satellite 10-5 because the optical telescope 12 has a problem with the tracking speed. For this reason, electronic scanning of the emitted light is required to capture the LEO satellite 10-5. Therefore, in this case, the control unit 16 of the LEO satellite 10-1 captures the LEO satellite 10-5 by scanning the emitted light using the optical phased array 13, and causes the light receiving element 14 to receive the incident light from the LEO satellite 10-5.

[0036] When capturing another LEO satellite 10 using the optical phased array 13, the control unit 16 preferably captures the other LEO satellite 10 near an intersection of orbital planes. This makes it possible to compensate for the low gain of the antenna provided in the LEO satellite 10.

[0037] Furthermore, when the control unit 16 uses the optical phased array 13 to capture another LEO satellite 10, it is preferable to capture the other LEO satellite 10 in an orbital plane at a different altitude within an orbit at an altitude of 300 km to 2000 km.

[0038] Moreover, the optical phased array 13 is preferably realized using an electro-optic polymer. Moreover, the optical phased array 13 is preferably realized using an optical waveguide based on silicon micromachining technology.

[0039] Next, an example of an operation flow when the LEO satellite 10 according to the present embodiment measures the distance to another LEO satellite 10 will be described with reference to Fig. 10. Here, the case where the LEO satellite 10-1 measures the distance to another LEO satellite 10 will be described as an example.

[0040] 10, the control unit 16 of the LEO satellite 10-1 captures the other LEO satellite 10 by scanning the outgoing light emitted from the light-projecting element 11 (step S101), and causes the light-receiving element 14 to receive the incident light from the captured other LEO satellite 10 (step S102). At this time, the control unit 16 performs the capture using the optical telescope 12 if the other LEO satellite 10 is a LEO satellite 10 in the same orbital plane, and performs the capture using the optical phased array 13 if the other LEO satellite 10 is a LEO satellite 10 in a different orbital plane.

[0041] Thereafter, the distance measurement unit 15 of the LEO satellite 10-1 measures the distance from the LEO satellite 10-1 to the other LEO satellites 10 based on at least one of the emitted light and the incident light (step S103). Note that the distance measurement method used by the distance measurement unit 15 may be any of the above-mentioned reflection type distance measurement method and two-way transmission and reception type distance measurement method.

[0042] <Effects of the embodiment> As described above, according to this embodiment, the control unit 16 captures the other LEO satellite 10 by scanning the outgoing light emitted from the light-projecting element 11, and causes the light-receiving element 14 to receive the incident light from the other LEO satellite 10. At this time, if the other LEO satellite 10 is a LEO satellite 10 in the same orbital plane, the control unit 16 performs the capture using the optical telescope 12, and if the other LEO satellite 10 is a LEO satellite 10 in a different orbital plane, the control unit 16 performs the capture using the optical phased array 13. Then, the ranging unit 15 measures the distance to the other LEO satellite 10 based on at least one of the outgoing light and the incident light.

[0043] Therefore, it is possible to measure the distance to another LEO satellite 10 not only when the other LEO satellite 10 is in the same orbital plane, but also when the other LEO satellite 10 is in a different orbital plane. This makes it possible to measure the distance between LEO satellites 10 without adding a ranging device to the LEO satellite 10.

[0044] In addition, to realize distributed MIMO by utilizing the antennas of the multiple LEO satellites 10 that make up the LEO satellite constellation, it is necessary to know the distance between these antennas, for example, in order to combine signals received by different antennas.

[0045] In this regard, according to the present embodiment, since the distance between the LEO satellites 10 can be measured, the distance between the antennas provided on the different LEO satellites 10 can be measured as the distance between the LEO satellites 10. This makes it possible to realize distributed MIMO by utilizing the antennas provided on the multiple LEO satellites 10.

[0046] <Hardware configuration of LEO satellite according to the embodiment> Next, an example of the hardware configuration of a computer 90 that realizes a part or all of the processing of the LEO satellite 10 according to the embodiment described above will be described with reference to Fig. 11. The computer 90 shown in Fig. 11 includes a processor 91 and a memory 92.

[0047] The processor 91 may be, for example, a microprocessor, a micro processing unit (MPU), or a central processing unit (CPU). The processor 91 may include multiple processors.

[0048] The memory 92 is configured by a combination of volatile memory and non-volatile memory. The memory 92 may include storage located away from the processor 91. In this case, the processor 91 may access the memory 92 via an I (Input) / O (Output) interface (not shown).

[0049] In addition, some of the components in the LEO satellite 10 in the above-mentioned embodiment (e.g., the ranging unit 15, the control unit 16, etc.) may be realized by the processor 91 reading and executing a program stored in the memory 92.

[0050] The above-mentioned program can be stored and provided to a computer using various types of non-transitory computer readable media. The non-transitory computer readable medium includes various types of tangible storage media. Examples of the non-transitory computer readable medium include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), compact disc-ROMs (CD-ROMs), CD-recordables (CD-Rs), CD-rewritables (CD-R / Ws), semiconductor memories (e.g., mask ROMs, programmable ROMs (PROMs), erasable PROMs (EPROMs), flash ROMs, and RAMs). The program may be provided to a computer by various types of transitory computer readable media. Examples of the transitory computer readable medium include electric signals, optical signals, and electromagnetic waves. The transitory computer readable medium can provide the program to a computer via a wired communication path such as an electric wire and an optical fiber, or via a wireless communication path.

[0051] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure.

[0052] For example, the LEO satellite 10 is generally equipped with an encoder. Therefore, the LEO satellite 10 may use the encoder to detect the angle of the emitted light and measure the altitude of the LEO satellite 10 based on the angle of the emitted light. Furthermore, the LEO satellite 10 may use the measured altitude for orbit correction, etc.

[0053] Furthermore, the LEO satellite 10 may include a millimeter wave sensor in the 30 GHz to 300 GHz band as the distance measurement unit 15. Here, with reference to FIG. 12, a configuration example of the millimeter wave sensor 17 in the LEO satellite 10 according to another embodiment will be described. Note that FIG. 12 shows a configuration example of the millimeter wave sensor 17 in the LEO satellite 10-1, but the millimeter wave sensors 17 in the other LEO satellites 10-2 to 10-5 have the same configuration. The millimeter wave sensor 17 shown in FIG. 12 is a millimeter wave sensor in the 30 GHz to 300 GHz band that includes a synthesizer 171, a TX antenna 172, an RX antenna 173, a mixer 174, and a calculation unit 175. The calculation unit 175 is realized by a processor such as a CPU. When measuring the distance from the LEO satellite 10-1 to the LEO satellite 10-2, the millimeter wave sensor 17 operates as follows. That is, the TX antenna 172 transmits a transmission wave to the LEO satellite 10-2, and the RX antenna 173 receives a wave reflected by the LEO satellite 10-2 of the transmission wave. The mixer 174 generates an intermediate frequency (IF) signal by mixing the transmission wave and the reception wave. The calculation unit 175 measures the distance from the LEO satellite 10-1 to the LEO satellite 10-2 based on the IF signal. Note that the millimeter wave sensor 17 is preferably realized using a 300 GHz band antenna. This allows the millimeter wave sensor 17 to be made smaller and lighter, thereby reducing the cost of the LEO satellite 10.

[0054] Furthermore, some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes. (Appendix 1) A LEO (Low Earth Orbit) satellite constellation, a light-projecting element that emits laser light as an emission light to another LEO satellite that constitutes the LEO satellite constellation; Optical telescopes, An optical phased array; a light receiving element that receives the laser light from the other LEO satellite as incident light; a distance measuring unit that measures a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; a control unit for controlling the light emitting element and the light receiving element, The control unit is With respect to the other LEO satellite in the same orbital plane as the LEO satellite, the outgoing light emitted from the light-projecting element is scanned using the optical telescope to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light-receiving element; Regarding the other LEO satellite in an orbital plane different from that of the LEO satellite, the optical phased array is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element. LEO satellite. (Appendix 2) Further comprising an atomic clock; the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a time from when the outgoing light is emitted to when the incident light is received by a pulse propagation method. A LEO satellite as described in Appendix 1. (Appendix 3) the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a phase difference between the emitted light and the incident light by a phase difference distance method. A LEO satellite as described in Appendix 1. (Appendix 4) the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the ranging unit measures the distance from the LEO satellite to the other LEO satellite based on a position on the light receiving element where the incident light is received by a triangulation method; A LEO satellite as described in Appendix 1. (Appendix 5) Further comprising an atomic clock; the incident light is a laser light emitted from the other LEO satellite and including information on a time of emission, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a time from when the incident light is emitted from the other LEO satellite to when the incident light is received. A LEO satellite as described in Appendix 1. (Appendix 6) When the control unit captures the other LEO satellite using the optical phased array, the control unit captures the other LEO satellite in an orbit having an altitude of 300 km to 2000 km and an orbital plane having an altitude different from that of the LEO satellite. 6. A LEO satellite as described in any one of appendixes 1 to 5. (Appendix 7) When capturing the other LEO satellite using the optical phased array, the control unit captures the other LEO satellite near an intersection of orbital planes. 6. A LEO satellite as described in any one of appendixes 1 to 5. (Appendix 8) The optical phased array is realized using an electro-optic polymer. 8. A LEO satellite as described in any one of Supplementary Notes 1 to 7. (Appendix 9) The optical phased array is realized using an optical waveguide based on silicon micromachining technology. 8. A LEO satellite as described in any one of Supplementary Notes 1 to 7. (Appendix 10) further comprising an encoder for detecting an angle of the emitted light; determining an altitude of the LEO satellite based on the angle of the emitted light; 10. A LEO satellite as described in any one of Supplementary Notes 1 to 9. (Appendix 11) It is equipped with multiple LEO (Low Earth Orbit) satellites that make up the LEO satellite constellation, each of the plurality of LEO satellites; a light-projecting element that emits laser light as an emission light to another LEO satellite that constitutes the LEO satellite constellation; Optical telescopes, An optical phased array; a light receiving element that receives the laser light from the other LEO satellite as incident light; a distance measuring unit that measures a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; a control unit for controlling the light emitting element and the light receiving element, The control unit is With respect to the other LEO satellite in the same orbital plane as the LEO satellite, the outgoing light emitted from the light-projecting element is scanned using the optical telescope to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light-receiving element; Regarding the other LEO satellite in an orbital plane different from that of the LEO satellite, the optical phased array is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element. LEO satellite system. (Appendix 12) Further comprising an atomic clock; the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a time from when the outgoing light is emitted to when the incident light is received by a pulse propagation method. 13. The LEO satellite system described in Appendix 11. (Appendix 13) the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a phase difference between the emitted light and the incident light by a phase difference distance method. 13. The LEO satellite system described in Appendix 11. (Appendix 14) the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the ranging unit measures the distance from the LEO satellite to the other LEO satellite based on a position on the light receiving element where the incident light is received by a triangulation method; 13. The LEO satellite system described in Appendix 11. (Appendix 15) Further comprising an atomic clock; the incident light is a laser light emitted from the other LEO satellite and including information on a time of emission, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a time from when the incident light is emitted from the other LEO satellite to when the incident light is received. 13. The LEO satellite system described in Appendix 11. (Appendix 16) When the control unit captures the other LEO satellite using the optical phased array, the control unit captures the other LEO satellite in an orbit having an altitude of 300 km to 2000 km and an orbital plane having an altitude different from that of the LEO satellite. 16. The LEO satellite system of any one of claims 11 to 15. (Appendix 17) When capturing the other LEO satellite using the optical phased array, the control unit captures the other LEO satellite near an intersection of orbital planes. 16. The LEO satellite system of any one of claims 11 to 15. (Appendix 18) The optical phased array is realized using an electro-optic polymer. 18. The LEO satellite system of any one of claims 11 to 17. (Appendix 19) The optical phased array is realized using an optical waveguide based on silicon micromachining technology. 18. The LEO satellite system of any one of claims 11 to 17. (Appendix 20) further comprising an encoder for detecting an angle of the emitted light; determining an altitude of the LEO satellite based on the angle of the emitted light; 20. The LEO satellite system of any one of claims 11 to 19. (Appendix 21) A method for controlling a LEO (Low Earth Orbit) satellite constellation, comprising: emitting laser light as an emission light to another LEO satellite constellation by a light emitting element; receiving, by a light receiving element, a laser beam from the other LEO satellite as incident light; measuring a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; A control step of controlling the light emitting element and the light receiving element, In the control step, With respect to the other LEO satellite in the same orbital plane as the LEO satellite, an optical telescope is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element; Regarding the other LEO satellite in an orbital plane different from that of the LEO satellite, an optical phased array is used to capture the other LEO satellite by scanning the emitted light emitted from the light projecting element, and the incident light from the other LEO satellite is received by the light receiving element. Control methods.

[0055] This application claims priority based on Japanese Patent Application No. 2021-053786, filed on March 26, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0056] 10-1~10-5 LEO satellite 11 Light emitting element 12 optical telescope 13 Optical Phased Array 14 Photodetector 15 Ranging section 16 Control section 17 mmWave Sensor 171 Synthesizer 172 TX Antenna 173 RX Antenna 174 Mixer 175 Calculation Department 21 Terminals 22 Aircraft 23 Parabolic antenna 90 Computer 91 Processor 92 Memory

Claims

1. A LEO (Low Earth Orbit) satellite constellation, a light projecting element that emits a laser beam as an emission light to another LEO satellite that constitutes the LEO satellite constellation; Optical telescopes, An optical phased array; a light receiving element for receiving the laser light from the other LEO satellite as incident light; a distance measuring unit that measures a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; a control unit for controlling the light emitting element and the light receiving element, The control unit is With respect to the other LEO satellite in the same orbital plane as the LEO satellite, the outgoing light emitted from the light projecting element is scanned using the optical telescope to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element; With respect to the other LEO satellite in an orbital plane different from that of the LEO satellite, the optical phased array is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element. LEO satellite.

2. Further comprising an atomic clock; the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a time from when the outgoing light is emitted to when the incident light is received, the time being measured using the atomic clock, by a pulse propagation method. The LEO satellite of claim 1 .

3. the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the distance measuring unit measures the distance from the LEO satellite to the other LEO satellite based on a phase difference between the emitted light and the incident light by a phase difference distance method. The LEO satellite of claim 1 .

4. the incident light is a laser light obtained by reflecting the emitted light on the other LEO satellite, the ranging unit measures the distance from the LEO satellite to the other LEO satellite based on a position on the light receiving element where the incident light is received by a triangulation method; The LEO satellite of claim 1 .

5. Further comprising an atomic clock; the incident light is a laser light emitted from the other LEO satellite and including information on a time of emission, the distance measurement unit measures the distance from the LEO satellite to the other LEO satellite based on a time from when the incident light is emitted from the other LEO satellite to when the incident light is received, the time being measured using the atomic clock; The LEO satellite of claim 1 .

6. When the control unit captures the other LEO satellite using the optical phased array, the control unit captures the other LEO satellite in an orbital plane having an altitude different from that of the LEO satellite within an orbit having an altitude of 300 km to 2000 km.

6. A LEO satellite according to any one of claims 1 to 5.

7. When capturing the other LEO satellite using the optical phased array, the control unit captures the other LEO satellite near an intersection of orbital planes.

6. A LEO satellite according to any one of claims 1 to 5.

8. The optical phased array is realized using an electro-optic polymer.

8. A LEO satellite according to any one of claims 1 to 7.

9. A plurality of LEO (Low Earth Orbit) satellites constituting a LEO satellite constellation are provided, each of the plurality of LEO satellites a light projecting element that emits a laser beam as an emission light to another LEO satellite that constitutes the LEO satellite constellation; Optical telescopes, An optical phased array; a light receiving element for receiving the laser light from the other LEO satellite as incident light; a distance measuring unit that measures a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; a control unit for controlling the light emitting element and the light receiving element, The control unit is With respect to the other LEO satellite in the same orbital plane as the LEO satellite, the outgoing light emitted from the light projecting element is scanned using the optical telescope to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element; With respect to the other LEO satellite in an orbital plane different from that of the LEO satellite, the optical phased array is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element. LEO satellite system.

10. A method for controlling a LEO (Low Earth Orbit) satellite constellation, comprising: emitting laser light as outgoing light to another LEO satellite constellation by a light emitting element; receiving, by a light receiving element, a laser beam from the other LEO satellite as incident light; measuring a distance from the LEO satellite to the other LEO satellite based on at least one of the emitted light and the incident light; A control step of controlling the light emitting element and the light receiving element, In the control step, With respect to the other LEO satellite in the same orbital plane as the LEO satellite, an optical telescope is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element; With respect to the other LEO satellite in an orbital plane different from that of the LEO satellite, an optical phased array is used to scan the emitted light emitted from the light projecting element to capture the other LEO satellite, and the incident light from the other LEO satellite is received by the light receiving element. Control methods.

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