JP7026300B2 - Spatial optical communication device - Google Patents

Description

The present invention relates to a space optical communication device that performs optical communication with a spacecraft such as an artificial satellite that orbits outer space.

In recent years, research has been conducted on optical satellite communication with ground stations on the earth using spacecraft such as artificial satellites that orbit the earth in outer space. This optical satellite communication is capable of large-capacity data transmission, can be realized with a lightweight and compact system configuration, and has advantages such as less interference than radio waves, so it is a technology that will be responsible for future space communication. It is attracting attention as.

Space-ground optical space transmission is performed in a cloud-free space (under the Earth's atmosphere) so that the transmission section is not blocked by clouds. On the other hand, the downlink transmitted from the spacecraft to the ground station is affected by atmospheric disturbance, the power that can be received on the receiving side decreases, the communication quality deteriorates, and in the worst case, information is lost in a burst. May be struck. Therefore, some kind of compensation technology that can suppress the influence of the atmosphere is required.

In order to solve such a problem, for example, Patent Document 1 describes path propagation in a space including a propagation path of a transmitted light wave emitted toward an artificial satellite while condensing the received light wave emitted from the artificial satellite. Light is focused by a telescope, and the angle of the propagation path of the transmitted light wave, which takes into account the effects of atmospheric fluctuations and fading, is calculated based on the wavefront distortion of the collected received light wave and path propagating light, and is transmitted at that angle. A spatial optical communication device that controls a variable mirror of a telescope so that a light wave reaches an artificial satellite is disclosed.

Japanese Unexamined Patent Publication No. 2018-12281

On the other hand, since a high-power laser is used for optical space transmission, when a flying object such as an aircraft passes through the transmission section, the transmission of the laser from the ground is stopped to ensure mutual safety between aerospace and aerospace. Operation is required. However, at present, the mainstream operation is to stop the laser transmission when the observer visually monitors the sky and confirms that the flying object is approaching the transmission section. Therefore, the monitoring and transmission of the flying object should be stopped. There is a need to build a system that can be linked and automatically performed.

In view of the above circumstances, an object of the present invention is to provide a spatial optical communication device capable of automatically monitoring a flying object and stopping laser transmission.

In order to achieve the above object, the spatial optical communication device according to one embodiment of the present invention includes a transmitting unit, a receiving unit, a monitoring unit, a beam monitor, and a control unit.
The transmission unit transmits the first laser beam toward the spacecraft.
The receiving unit receives the second laser beam transmitted from the spacecraft.
The monitoring unit monitors a flying object flying over the emission direction of the first laser beam.
The beam monitor detects the emission direction of the first laser beam from the transmitting unit.
The control unit sets a first monitoring area for partitioning the periphery of the first laser beam based on the output of the beam monitor, and based on the output of the monitoring unit, the flying object is transferred to the first monitoring area. When the approach is determined, a control signal for stopping the transmission of the first laser beam is generated.

According to the space optical communication device, a series of controls for monitoring the relative position between the first laser beam and the flying object and stopping the emission of the first laser beam when the flying object approaches the first laser beam more than a predetermined value. Can be done automatically.

The control unit may be configured to set the first monitoring area wider as the flying object moves away from the transmission unit.

The spatial optical communication device may further include an alarm. The control unit further sets a second monitoring area that partitions the periphery of the first monitoring area, and outputs a control signal for activating the alarm when the flying object is determined to enter the second monitoring area. It may be generated.

The beam monitor has a camera unit that captures the scattered light of the first laser beam in the atmosphere, and the camera unit captures an image of the scattered light observed from two directions intersecting each other at a predetermined angle. It may be configured to acquire.

The monitoring unit may include a plurality of monitoring devices having different monitoring distances.

The monitoring unit may include a thermal infrared camera, a radar device, or a receiving device that receives identification information transmitted from the projectile.

The space optical communication device may further include a display unit capable of displaying the relative positional relationship between the first laser beam, the flying object, and the first monitoring region.

The space optical communication device has a light receiving surface that receives the second laser beam, and further includes a seeing monitor that detects fluctuations in the atmosphere on the propagation path of the second laser beam, and the control unit is the control unit. It may be configured to set the size of the first monitoring area based on the output of the seeing monitor.

The space optical communication device further includes a light receiving intensity monitor for detecting the light receiving intensity of the second laser beam, and the control unit has a spread angle of the first laser beam and a light receiving intensity monitor based on the output of the light receiving intensity monitor. It may be configured to generate a control signal that controls the power.

According to the present invention, the space optical communication device can automatically monitor the flying object and stop the laser transmission.

It is a schematic block diagram which shows the space optical communication system which includes the space optical communication apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows one configuration example of the transmission part in the said space optical communication apparatus. It is a schematic diagram explaining the influence by the fluctuation of the atmosphere of the downlink (second laser beam) transmitted from a spacecraft to a space optical communication device. It is a schematic perspective view which shows one configuration example of the seeing monitor in the said space optical communication apparatus. It is a schematic diagram which shows the image formation image of the 2nd laser beam on the light receiving surface of the seeing monitor. It is a schematic diagram which shows one configuration example of the light receiving intensity monitor in the said space optical communication apparatus. It is a schematic diagram explaining the beam wandering phenomenon of the uplink (first laser beam) transmitted to a spacecraft. It is a figure which shows one configuration example of the beam monitor in the said space optical communication apparatus. It is explanatory drawing of the structure of the said beam monitor. It is a figure explaining the operation of the said beam monitor. It is a figure which shows the other configuration example of the said beam monitor. It is a functional block diagram which shows the structure of the control part in the said space optical communication apparatus. It is a flowchart which shows an example of the processing procedure of the beam control mode executed in the said control unit. It is a figure which shows an example of the acquisition image of the monitoring unit in the said space optical communication apparatus. It is a conceptual diagram of the 1st monitoring area and the 2nd monitoring area A2 set based on the output signal from the monitoring unit in the space optical communication device. It is explanatory drawing of the 1st monitoring area and the 2nd monitoring area. It is a sequence diagram which shows the operation of each part of a space optical communication apparatus in time series at the time of execution of a monitoring mode. It is a flowchart which shows an example of the processing procedure of the said control part. It is a flowchart which shows an example of the processing procedure of the said control part. It is a flowchart which shows an example of the processing procedure of the said control part. It is a flowchart which shows an example of the processing procedure of the said control part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a spatial optical communication system 100 according to an embodiment of the present invention. The space optical communication system 100 includes a space optical communication device G and a spacecraft S, and performs optical communication (satellite communication) between the space optical communication device G and the spacecraft S.

Spacecraft S typically means a structure having a communication function capable of moving in outer space, such as an artificial satellite or a space station. Artificial satellites include geostationary orbits (GEO: Geostationary Earth Orbit), as well as low earth orbit (LEO) and medium earth orbit (MEO), regardless of the rotation period of the earth. Furthermore, it includes artificial satellites that fly in deep space. That is, the altitude of the spacecraft S from the ground surface is not particularly limited. The artificial satellite is typically a meteorological satellite, a communication satellite, or the like, but may be launched for any purpose.

[Spatial optical communication device]
The space optical communication device G is configured as a ground station that performs optical space transmission with the spacecraft S. The space optical communication device G includes a telescope 10 for receiving an optical signal (downlink) transmitted from the spacecraft S or transmitting and receiving an optical signal to and from the spacecraft S. In the present embodiment, the telescope 10 is mainly configured as a receiving unit that receives the downlink (second laser beam L2) transmitted from the spacecraft S.

The second laser beam L2 may be a continuous laser or a pulse laser. The second laser beam L2 is typically infrared light having a wavelength of, for example, 1550 nm or 1064 nm.

The telescope 10 is installed on a base 11 installed on the ground. The base 11 has an adjustment mechanism 11a for adjusting the attitude of the telescope 10, and the telescope 10 is supported by the base 11 so as to be able to track the spacecraft S. The base 11 controls the orientation and / or elevation angle of the optical axis of the telescope 10 so as to track the spacecraft S according to the forecast value. The predicted value is the space coordinate of the spacecraft S calculated from the orbit of the spacecraft S, and is the first laser beam L1 or the second laser beam L2 of the space transmission path from the installation location of the base 11 to the spacecraft S. The refractive index at the wavelength of the above may be taken into consideration.

The aperture of the telescope 10 is not particularly limited, and is, for example, 30 cm to 10 m. The opening of the telescope 10 is not limited to a single number, and may be a plurality of openings. The telescope 10 has a signal processing unit (not shown) that converts the focused second laser beam L2 into an electric signal and performs predetermined signal processing such as analysis of received information.

The space optical communication device G is not limited to the example configured as a ground station, and may be mounted on a moving body such as a vehicle, a ship, or an aircraft. Further, the space optical communication device G may be connected to a communication body such as a gateway, a terrestrial communication network installed on the ground, a vehicle, a ship, an aircraft, or the like. In this case, the gateway, the terrestrial communication network, the communication body, and the like transmit and receive optical signals to and from the spacecraft S via the space optical communication device G.

The spatial optical communication device G includes a transmission unit 20, a seeing monitor 31, a light receiving intensity monitor 32, a beam monitor 33, a control unit 40, and a monitoring unit 60.
The transmission unit 20 emits the first laser beam L1 transmitted toward the spacecraft S. The seeing monitor 31 detects the atmospheric state (or beam position information reflecting the atmospheric condition) on the propagation path of the second laser beam L2 based on the second laser beam L2 transmitted from the spacecraft S. .. The light receiving intensity monitor 32 detects the light receiving intensity of the second laser beam L2. The beam monitor 33 detects the emission direction of the first laser beam L1 (as will be described later in this embodiment, the first laser is used to detect the beam emission angle (direction, elevation angle) affected by the beam wonder. Monitor the scattered light L1s of the light L1). The monitoring unit 60 monitors a flying object flying over the emission direction of the first laser beam L1. The control unit 40 controls the direction and elevation angle of the optical axis of the telescope 10 so that the spacecraft S can be tracked according to the forecast value. The control unit 40 controls the transmission unit 20 based on the outputs of the seeing monitor 31, the light receiving intensity monitor 32, the beam monitor 33, and the monitoring unit 60.

(Sender)
The transmission unit 20 has a laser light source that generates a first laser beam L1 for uplink. The first laser beam L1 mainly functions as guided light for emitting the downlink of the spacecraft S toward the space optical communication device G. The first laser beam L1 may be a continuous laser or a pulse laser. The first laser beam L1 is typically infrared light, the wavelength of which is, for example, 1550 nm or 1064 nm. The spread angle and power of the first laser beam L1 are not particularly limited, and for example, the spread angle is 50 μrad to 1 rad, and the power is 1 W to several tens of kW (for example, 50 kW).

By attaching the transmission unit 20 to the outer peripheral portion of the telescope 10, the transmission unit 20 is configured to be integrally movable with the telescope 10 with respect to the base 11. The optical axis of the first laser beam L1 in the transmission unit 20 is installed in parallel with the optical axis of the telescope 10. In the present embodiment, there are multiple laser emitting units, and each laser emitting unit is configured to emit the first laser beam L1 toward the spacecraft S. Of course, the number of laser emitting units is not limited to a plurality, and may be a single number. Further, the transmission unit 20 is not limited to the example of being attached to the outer peripheral portion of the telescope 10, and may be arranged inside the telescope 10.

FIG. 2 is a schematic diagram showing a configuration example of the transmission unit 20. The transmission unit 20 has a casing 21 and a plurality of (two in this example) laser emission units 22. The laser emission unit 22 is arranged inside the casing 21, and has a laser light source 221, a lens unit 222, an emission mirror 223, a shutter 224, and the like, respectively.

The casing 21 is fixed to the outer peripheral portion of the telescope 10. A window portion 21W (see FIG. 1) for transmitting the first laser beam L1 emitted from each laser emitting unit 22 is provided on the light emitting surface of the casing 21. The laser light source 221 is a laser diode that emits the first laser beam L1, and the lens unit 222 includes a plurality of lenses that can arbitrarily adjust the spread angle of the emitted light from the laser light source 221. As the lens unit 222, a lens unit typically called a beam expander can be used. The emission mirror 223 includes a plurality of mirror elements that guide the emission light from the lens unit 222 to the window portion 21W. The plurality of mirrors typically includes a plurality of variable mirrors in which the emission angle of the first laser beam L1 from the window portion 21W can be individually adjusted in two axial directions orthogonal to each other with respect to the optical axis. The shutter 224 is arranged at an arbitrary position in the emission path of the laser beam, and is configured to be able to shield the emission light from the laser light source 221.

The transmission unit 20 further includes a drive circuit 23 that supplies electric power to each laser light source 221 and an amplifier 24 that adjusts the current value supplied to each laser light source 221. The laser emission unit 22, the drive circuit 23, and the amplifier 24 can be individually controlled based on a command from the control unit 40, which will be described later.

(Seeing monitor)
The seeing monitor 31 detects the state of the atmosphere on the propagation path of the second laser beam L2 transmitted from the spacecraft S to the space optical communication device G. In the present embodiment, a DIMM (Differential Image Motion Monitor) is adopted as the seeing monitor 31 in order to detect the beam position of the second laser beam L2 reflecting the state of the atmosphere as position information.

Here, the state of the atmosphere typically means the fluctuation of the atmosphere (seeing). Atmospheric fluctuations fluctuate depending on weather conditions, air pollution, surrounding topography, time, seasons, and so on. Spatial optical transmission between the spacecraft S and the space optical communication device G is due to the influence of the atmosphere on the ground (for example, continuous changes in the refractive index due to continuous changes in atmospheric concentration from the ground to outer space, aerosols, etc.). It is strongly exposed to light scattering by fine particles in the atmosphere. Therefore, in consideration of this atmospheric influence, the spread angle, the transmission intensity, and the transmission direction are set in advance so that the uplink (first laser beam L1) as the guided light reaches the spacecraft S.

FIG. 3 is a schematic diagram illustrating the influence of the fluctuation of the atmosphere of the downlink (second laser beam L2) transmitted from the spacecraft S to the space optical communication device G. As shown in FIG. 3, the wavefront L2w of the second laser beam L2 transmitted from the spacecraft S is a flat surface in outer space, whereas it is a distorted surface in the atmosphere. The degree of this distortion changes depending on the atmospheric conditions, and as the intensity of atmospheric fluctuation increases, the focal position shifts. In this way, by detecting the shift amount of the focal position of the second laser beam L2 on the seeing monitor 31, it is possible to detect the intensity of the fluctuation of the atmosphere in the propagation path of the second laser beam L2.

FIG. 4 is a schematic perspective view showing a configuration example of the seeing monitor 31. The seeing monitor 31 has, for example, a reflecting telescope structure having a diameter of 10 cm or less. The seeing monitor 31 has a tubular portion 311 fixed to the outer peripheral portion of the telescope 10, two prisms (or wedges) 312 arranged apart from each other at the tip of the tubular portion 311 and a tubular portion via the prism 312. It has a first mirror 313 and a second mirror 314 that reflect the second laser beam L2 that has traveled to 311 and an infrared camera 315 having a light receiving surface 315a that receives the reflected light of the second mirror 314.

FIG. 5 is a schematic view showing an image of the second laser beam L2 on the light receiving surface 315a. In the figure, the X-axis and the Y-axis indicate the horizontal axis and the vertical axis of the light receiving surface 315a, respectively, and the Z-axis corresponds to the optical axis (axis center) of the seeing monitor 31. In the figure, P0 indicates the focal position (hereinafter, also referred to as a reference point) of each laser beam transmitted through the two prisms 312 at the reference value (initial value at the start of light reception). The seeing monitor 31 detects the amount of shift (X / Y) in the X-axis and Y-axis directions from the reference point P0 of the two imaging points P of the laser beam on the light receiving surface 315a. Specifically, seeing [arcsec] is performed by a known method from the incident angle obtained from the focal length of the optical system constituting the seeing monitor 31 and the shift amount in the X-axis and Y-axis directions from the reference point P0. calculate.

The seeing monitor 31 outputs the detection signal to the calculator 50 (see FIG. 1). The calculator 50 calculates the Fried parameter Ro [mm] related to the fluctuation of the atmosphere from the relative positions of the two imaging points P detected by the infrared camera 315. The freed parameter Ro is an index for quantitatively evaluating seeing, is calculated by a predetermined arithmetic expression, and is output to the control unit 40. The control unit 40 generates a control signal for controlling the first laser beam L1 based on the calculated freed parameter Ro and the output of the light receiving intensity monitor 32 described later, and outputs the control signal to the transmission unit 20.

The arithmetic unit 50 may be configured as a part of the seeing monitor 31 or as a part of the control unit 40. Further, the seeing and freed parameter calculation processing may be executed by the control unit 40.

When calculating the freed parameter Ro, a correction coefficient corresponding to the diameter of the seeing monitor 31 may be multiplied. It is known that DIMMs generally have a diameter of 25 cm or more, and a measurement error becomes large when the diameter is smaller than the diameter. However, in order to measure the downlink light at the same time and control the upling during satellite tracking, the DIMM is small enough to be mounted on the telescope aperture (about 0.3m to 10m) assumed in space communication. Need to be.

Therefore, in the present embodiment, for DIMMs having a diameter of 10 cm or less applied to the seeing monitor 31, a correction coefficient based on statistical analysis compared with a reference telescope having a diameter of about 25 cm is calculated in advance, and the correction coefficient is used in the seeing monitor 31. The freed parameter R0 is calculated from the value obtained by multiplying the output. This makes it possible to suppress the harmful effects of DIMM measurement errors caused by miniaturization and to measure the atmospheric condition with high accuracy.

(Light receiving intensity monitor)
The light receiving intensity monitor 32 detects the light receiving intensity of the second laser beam L2 transmitted from the spacecraft S to the space optical communication device G. In the present embodiment, the light receiving intensity monitor 32 is arranged adjacent to the seeing monitor 31 on the outer peripheral portion of the telescope 10, but the mounting position is not limited to this. The light receiving intensity monitor 32 is composed of a photoelectric conversion element capable of detecting the light receiving intensity of the second laser beam L2 per unit area.

FIG. 6 is a schematic diagram showing a configuration example of the light receiving intensity monitor 32. The light receiving intensity monitor 32 has a condenser lens 322 and a light receiving sensor 323 that receives the second laser beam L2 focused by the condenser lens 322 in the tubular portion 321. The light receiving sensor 323 is a photoelectric conversion element that outputs a current value corresponding to the intensity of the second laser beam L2, and the output [dBm] is supplied to the control unit 40.

(Beam monitor)
The uplink (first laser beam L1) emitted from the transmission unit 20 is also affected by fluctuations in the atmosphere above, refractive index that changes stepwise depending on altitude, etc., and its intensity is attenuated or the propagation direction is meandering. do. This phenomenon is called beam wandering, and the state is schematically shown in FIG.

When the beam meandering caused by the beam wandering of the first laser beam L1 for uplink is larger than a predetermined value, it becomes difficult for the first laser beam L1 to reach the spacecraft S. Therefore, for the spacecraft S, the first laser beam The detection accuracy of L1 is lowered. As a result, the accuracy of the emission direction of the second laser beam L2 for downlink is lowered, so that the light receiving intensity of the second laser beam L2 in the space optical communication device G is also lowered. Therefore, in the present embodiment, the beam monitor 33 observes the beam meandering affected by the beam wandering of the first laser beam L1 for uplink, and the emission direction of the first laser beam L1 is determined according to the result of the observed value. Is configured to control.

Specifically, the emission direction (direction, elevation angle) of the beam is calculated from the observed value, and the difference value from the predicted value (direction, elevation angle) regarding the spatial position of the spacecraft S is calculated. The control unit 40 generates a control signal for correcting the emission direction of the first laser beam L1 so as to cancel the difference value.

8 and 9 are principle diagrams showing a configuration example of the beam monitor 33. The beam monitor 33 is composed of a camera unit configured to be capable of photographing scattered light L1s by atmospheric particles or the like of the first laser light L1 emitted from the transmission unit 20 in the sky. The beam monitor 33 includes a housing 331, a first mirror 332, a second mirror 333, a third mirror 334, a beam splitter 335, a camera 336, and an image processing unit 337, which are arranged inside the housing 331, respectively.

The first mirror 332 and the second mirror 333 reflect the scattered light L1s (L1sx, L1sy) of the first laser beam L1 emitted from the transmission unit 20 due to the atmosphere. The scattered light L1sx reflected by the first mirror 332 is incident on the camera 336 via the beam splitter 335. On the other hand, the scattered light L1sy reflected by the second mirror 333 is incident on the camera 336 via the third mirror 334 and the beam splitter 335.

The camera 336 acquires images of scattered light L1sx and L1sy observed from two directions intersecting each other at a predetermined angle. That is, the beam splitter 335, the first mirror 332, and the second mirror 333 are arranged so that the two reflected lights incident on the beam splitter 335 form a predetermined angle. In FIGS. 8 and 9, the beam splitter 335, the first mirror 332, and the second mirror 333 are arranged so that the two reflected lights incident on the beam splitter 335 are orthogonal to each other. Further, as will be described later, the captured image 336v of the camera 336 is output to the image processing unit 337.

In FIG. 9, the Z-axis indicates the emission center of the first laser beam L1 in the transmission unit 20, and the X-axis and Y-axis directions indicate biaxial directions orthogonal to the Z-axis. The first mirror 332 reflects the scattered light L1sx of the first laser beam L1 seen from the X plane (first plane) parallel to the XZ plane, and the second mirror 333 intersects the X plane at a predetermined angle ( In this embodiment, the scattered light L1sy of the first laser beam L1 seen from the Y plane (second plane) parallel to the XY plane, which is orthogonal to the XY plane, is reflected. The camera 336 is an infrared camera, and the projected image of the scattered light L1sx on the X plane of the first laser beam L1 traveling while refracting or diverging in the X plane and the traveling while refracting or diverging in the Y plane. The projected image of the scattered light L1sy on the Y plane of the first laser light L1 is acquired at the same time.

FIG. 10 is a diagram showing an image 336v of scattered light L1sx and L1sy acquired by the camera 336. The camera 336 is an infrared camera. In the figure, the angle formed by the + X direction and the −X direction corresponds to the scattering angle of the scattered light L1x, and the angle formed by the + Y direction and the −Y direction corresponds to the scattering angle of the scattered light L1y. The image processing unit 337 analyzes the image of the scattered light L1x and L1y to analyze the shape of the emitted beam affected by the beam wandering of the first laser light L1 and outputs it to the control unit 40. Typically, the control unit 40 superimposes the images of the scattered light L1sx and the scattered light L1sy to determine the propagation direction of the first laser beam L1. The calculation of the propagation direction is not limited to the case where it is executed by the control unit 40, and may be executed by the image processing unit 337.

The beam monitor 33 is not limited to the example of being composed of one camera 336, and may be composed of two cameras. An example of the configuration is schematically shown in FIG. In FIG. 11, the scattered light L1sx and L1sy reflected by the first mirror 332 and the second mirror 333 are incident on the first camera 336a and the second camera 336b via the beam splitter 338, respectively. In this case, the image processing unit 337 determines the propagation direction of the emitted beam affected by the beam wandering of the first laser beam L1 from the images of the scattered light L1sx and L1sy acquired by the first camera 336a and the second camera 336b. measure.

(Monitoring unit)
The monitoring unit 60 monitors a flying object (presence / absence of a flying object, moving direction of the flying object, etc.) flying over the emission direction of the first laser beam L1. As the monitoring unit 60, a monitoring device capable of monitoring a flying object flying over the emission direction of the first laser beam L1 is used. This type of monitoring device can use a single number or type of monitoring device, but typically multiple types of monitoring devices with different monitoring distances are used. Preferably, as the monitoring device, a monitoring device for a short distance (for example, 2 km or less), a monitoring device for a medium distance (for example, over 2 km to 50 km), and a monitoring device for a long distance (for example, over 50 km) are used. Be done.

As shown in FIG. 1, in the present embodiment, the monitoring unit 60 includes a thermal infrared camera 61 for short-distance monitoring, a radar device 62 for medium-distance monitoring, and a data acquisition device 63 for long-distance monitoring. Of course, it is not necessary to include all of these monitoring devices (61 to 63) as the monitoring unit 60, and for example, the monitoring unit 60 may be configured only by the thermal infrared camera 61 and the radar device 62.

As shown in FIG. 1, the thermal infrared camera 61 is attached to the outer peripheral portion of the telescope 10. In the present embodiment, the image is arranged in the vicinity of the beam monitor 33, and the sky is photographed with a wider viewing angle than the beam monitor 33. The shooting target of the thermal infrared camera 61 includes a flying object F, a cloud C, and the like. The projectile F typically includes a flying object such as an aircraft or a helicopter, as well as a hot air balloon or the like. The projectile is not limited to a manned aerial vehicle, but may be an unmanned aerial vehicle (drone).

The radar device 62 is, for example, an X-band radar detector. The radar device 62 is deployed at a radar base installed at a location distant from the telescope 10. The radar device 62 measures the distance from the radar device 62 to the projectile F based on the time difference between the transmission time of the transmission wave R and the reception time of the received wave which is the reflected wave thereof, and the position (latitude, Calculate longitude, altitude).

The data acquisition device 63 is, for example, a receiving device capable of acquiring the information wirelessly or by wire from a data transmission source that transmits information regarding the model and position of the projectile F. The data transmission source may be a domestic or foreign data server, or may be a transmission terminal mounted on the projectile F.

The outputs of the thermal infrared camera 61, the radar device 62, and the data acquisition device 63 are supplied to the control unit 40. In the present embodiment, the outputs of the radar device 62 and the data acquisition device 63 are supplied to the control unit 40 via the communication device 64, but are not limited to this, and are individually and directly supplied to the control unit 40. May be done.

The space optical communication device G further includes a display unit 70 that displays the monitoring results of the flying object F and the cloud C by the monitoring unit 60, and an alarm device 80 that activates an alarm when the flying object F approaches the first laser beam L1. Etc. are provided. Examples of the alarm device 80 include an electroacoustic conversion device such as a buzzer and a siren, a light emitting device such as a lamp, and an electronic transmission device that electronically transmits an alarm by a command, text, an image (including a design such as an icon), or the like. Can be mentioned.

(Control unit)
The control unit 40 comprehensively controls the operation of each unit of the space optical communication device G (see FIG. 12). The control unit 40 is typically composed of a computer having a CPU (Central Processing Unit) and a memory. The control unit 40 is used for the acquisition unit 41 that acquires the outputs of the seeing monitor 31 (or the arithmetic unit 50), the light receiving intensity monitor 32, the beam monitor 33, and the monitoring unit 60, and the output of each monitor acquired by the acquisition unit 41. Based on this, a determination unit 42 for determining the beam spreading angle (beam width) of the first laser beam L1 and the presence / absence of power correction, etc., and a control signal for controlling the transmission unit 20 based on the output of the determination unit 42 are generated. Based on the output of the signal generation unit 43 and the monitoring unit 60, the monitoring results of the projectile F and the cloud C are generated as a display signal in an image format that can be visually recognized by a person, and / or the first unit from the transmission unit 20. It has a monitoring unit 44 that generates a control signal for stopping the transmission of the laser beam L1.

In the present embodiment, the control unit 40 controls the transmission unit 20 by controlling the beam control mode for controlling the beam characteristics of the first laser beam L1 emitted from the transmission unit 20 and the aerospace and aerospace when the projectile F approaches. From the viewpoint of ensuring safety, it is possible to execute two control modes of a monitoring mode for stopping the transmission of the first laser beam L1.

[Operation of spatial optical communication device]
Hereinafter, the details of the configuration of the control unit 40 will be described together with the operation of the space optical communication device G.

(Beam control mode)
FIG. 13 is a flowchart showing an example of the processing procedure of the beam control mode executed by the control unit 40.

As shown in FIG. 1, the space optical communication device G transmits the first laser beam L1 for uplink from the transmission unit 20 toward the spacecraft S, and the spacecraft S transmits the first laser beam L1 in the direction of arrival of the first laser beam L1. The second laser beam L2 for downlink is transmitted toward. The telescope 10 collects the second laser beam L2 and performs predetermined signal processing. The control unit 40 controls the transmission unit 20 that emits the first laser light L1 by executing the first and second loop processes described later based on the light receiving intensity Rx and the like of the second laser light L2.

(First loop processing)
The control unit 40 acquires or calculates atmospheric fluctuations (seeing) and the freed parameter Ro based on the outputs of the seeing monitor 31 and the arithmetic unit 50 (steps 101 and 102). Further, the control unit 40 acquires or calculates the light receiving intensity Rx of the second laser beam L2 based on the output of the light receiving intensity monitor 32 (step 103).

Subsequently, the control unit 40 determines whether or not the light receiving intensity Rx of the second laser beam L2 has reached a predetermined intensity range (step 104). The predetermined intensity range typically refers to the intensity range of the second laser beam L2 required for proper signal processing of the received signal by the telescope 10, even if it is an arbitrary point (target value). However, in order to improve the stability of control, in this example, it is set within a predetermined range centered on the target value.

When the light receiving intensity Rx of the second laser beam L2 is within a predetermined intensity range, it can be considered that there is no fluctuation in the fluctuation of the atmosphere. Therefore, in this case, the control unit 40 maintains the current emission conditions (beam spread angle, transmission power (Tx)) of the first laser beam L1 as they are (steps 105 and 106), and processes in steps 101 to 106 described above. (Hereinafter, also referred to as the first loop processing) is repeated.

In the above example, the first loop process is executed with only the light receiving intensity Rx of the second laser beam L2 as the monitoring target, but the present invention is not limited to this, and the beam wonder w of the second laser beam L2 and the second laser beam L2 are not limited to this. The first loop process may be executed with both of the light receiving intensity Rx of the above as the monitoring target (the same applies to the second loop process described later). In this case, for example, a process of calculating the beam wonder w of the second laser beam L2 is added between the step 102 and the step 103. The beam wonder w of the second laser beam L2 can be calculated based on the freed parameter acquired in step 102, the laser wavelength and beam diameter of the second laser beam L2, the propagation distance, and the like.

(Second loop processing)
As a factor that the light receiving intensity of the second laser beam L2 does not fall within the predetermined intensity range, the atmospheric fluctuation fluctuates with time, and as a result, the intensity of the first laser beam L1 reaching the spacecraft S is attenuated, and the spacecraft S It is not possible to accurately detect the arrival direction of the captured first laser beam L1. Therefore, in the second loop processing, the spread angle and the transmission of the first laser beam L1 emitted from the transmission unit 20 so that the spacecraft S can accurately detect the arrival direction of the first laser beam L1. The power Tx is corrected.

When the control unit 40 determines that the light receiving intensity of the second laser beam L2 is not within the predetermined intensity range, the control unit 40 executes the second loop process (steps 107 to 111).

The control unit 40 determines whether or not the light receiving intensity of the second laser beam L2 is less than a predetermined intensity range (step 107). When the determination result in step 107 is "Yes", the control unit 40 increases the beam spreading angle of the first laser beam L1 by n (n is a positive number larger than 1) times the current value, and transmits power (Tx). Generates a control signal for increasing ⁿ times the current value by n and outputs it to the transmission unit 20 (steps 108 and 109).

As a result, the beam width of the first laser beam L1 is widened, so that the amount of light of the first laser beam L1 reaching the spacecraft S can be increased. As a result, since the arrival direction of the first laser beam L1 captured by the spacecraft S can be accurately detected, the direction of the second laser beam L2 transmitted from the spacecraft S toward the space optical communication device G. The accuracy is improved, and the light receiving intensity Rx can be increased. Further, since the transmission power Tx is increased at the same time as the beam expansion angle is expanded, the decrease in light energy per unit area due to the beam expansion angle is suppressed.

The spread angle of the first laser beam L1 can be changed to an arbitrary size by adjusting the distance between each lens in the lens unit 222 of the transmission unit 20, and the transmission power Tx adjusts the amplifier 24 of the transmission unit 20. You can change it to any size with.

The value of n may be a fixed value, or may be a variable value predetermined in accordance with the amount of shift of the light receiving intensity Rx (or beam wonder w) of the second laser beam L2 from a predetermined range. The value of n may be the same value as the control amount of the beam spread angle and the transmission power, or may be a different value. Further, the value of n may be dynamically changed based on a predetermined table or algorithm from the information on the fluctuation of the atmosphere acquired in step 101, the freed parameter acquired in step 102, and the like.

The value of n is not particularly limited, and is typically a value of 1.5 or more and 10 or less, preferably 2 or more and 5 or less. Although it depends on the atmospheric condition, when the value of n is less than 1.5, the effect of the spacecraft S to capture the first laser beam L1 may not be sufficient. Further, when the value of n exceeds 10, the transmission power of the first laser beam L1 becomes excessive, which may hinder the efficient operation of the electric power in the space optical communication device G.

When the determination result in step 107 is "No", the control unit 40 sets the beam spreading angle of the first laser beam L1 to be n (n is a positive number larger than 1) times the current value, and the transmission power (Tx). Generates a control signal for reducing the current value by ⁿ times, and outputs the control signal to the transmission unit 20 (steps 110 and 111). As a result, the beam width of the first laser beam L1 is narrowed and the transmission power is also reduced, so that the excessive output of the first laser beam L1 can be suppressed.

The control unit 40 re-executes the first loop process after executing the second loop process described above. The control unit 40 repeatedly executes the second loop process until the light receiving intensity Rx of the second laser beam L2 falls within a predetermined range.

As described above, by correcting the emission conditions of the first laser beam L1 for uplink in real time according to the ever-changing atmospheric conditions, the second laser beam L2 transmitted from the spacecraft S is stable. Reception can be maintained. Therefore, according to the present embodiment, it is possible to realize highly adaptable spatial optical communication capable of following the ever-changing atmospheric state.

(Monitoring mode)
Subsequently, the monitoring mode of the control unit 40 will be described.

The control unit 40 confirms the existence of the cloud C in the sky above the emission direction of the first laser beam L1 based on the output of the thermal infrared camera 61 or the like, and when it approaches the first laser beam L1 by a predetermined value or more, the first It is configured to execute a control to stop the transmission of the laser beam L1. As a result, it is possible to prevent the communication with the spacecraft S from being interrupted due to the scattering of the first laser beam L1 in the cloud C.

When the monitoring mode is executed, the control unit 40 determines the first laser beam L1 and the projectile F based on the information regarding the emission direction of the first laser beam L1 output from the beam monitor 33 and the output signal from the monitoring unit 60. When the flying object F approaches the first laser beam L1 by a predetermined value or more, the control for stopping the transmission of the first laser beam L1 is executed. This makes it possible to prevent the projectile F from being irradiated with the first laser beam L1.

Hereinafter, the details of the monitoring mode by the control unit 40 will be described with a focus on monitoring the relative positions of the flying object F and the first laser beam L1.

The control unit 40 sets a first monitoring area that partitions the periphery of the first laser beam L1 based on the output of the beam monitor 33, and enters the first monitoring area of the projectile F based on the output of the monitoring unit 60. Is determined, a control signal for stopping the transmission of the first laser beam L1 is generated.
The control unit 40 further sets a second monitoring area that partitions the periphery of the first monitoring area, and generates a control signal that activates the alarm device 80 when it is determined that the flying object has entered the second monitoring area. ..

For example, FIG. 14 shows an example of an image 61V transmitted from the thermal infrared camera 61. The image 61V is an image of a plane orthogonal to the emission optical axis of the first laser beam L1 in the transmission unit 20, and is an optical axis (inverted triangles (two)) of the first laser beam L1 at the focal length of the thermal infrared camera 61. (Fig.) And the relative position of the projectile F are shown. The control unit 40 sets a first monitoring area A1 for partitioning the periphery of the first laser beam L1 from the image 61V and a second monitoring area A2 for partitioning the periphery of the first monitoring area A1.

The first monitoring region A1 is an region of an arbitrary width in which the flying object F may be irradiated with the first laser beam L1, and its shape is not limited to the circular shape shown in the figure, but may be an ellipse, a polygon, or the like. There may be. The first laser beam L1 is refracted or scattered under the influence of the atmosphere in its propagation path, and the propagation direction may fluctuate according to the altitude. Therefore, the first monitoring region A1 is set in consideration of the variation in the propagation direction of the first laser beam L1, and is typically formed by an arbitrary closed curve including the first laser beam L1. The shape and size of the first monitoring region A1 are, for example, atmospheric fluctuation information acquired from the seeing monitor 31, information regarding the emission direction of the first laser beam L1 acquired from the beam monitor 33, and execution of the above-mentioned beam control mode. It may be changed dynamically based on the beam spread angle corrected by.

The second monitoring area A2 is an area set to warn the outside of the approach of the flying object F to the first monitoring area A1, and may be omitted if necessary. The second monitoring area A2 is formed by a closed curve having an arbitrary shape including the first monitoring area A1, and the shape and size (width) thereof can be arbitrarily set.

It is preferable that the position of the first laser beam L1 is corrected based on the output signal from the beam monitor 33 that detects the emission direction of the first laser beam L1. As a result, the position accuracy of the first laser beam L1 in the field of view of the image 61V is improved, and the first monitoring area A1 and the second monitoring area A2 can be set to an appropriate width without unnecessarily expanding.

FIG. 15 is a conceptual diagram of a first monitoring area A1 and a second monitoring area A2 set based on an output signal from the radar device 62 or the data acquisition device 63. Since the radar device 62 and the data acquisition device 63 can acquire the latitude, longitude, and altitude of the projectile F, the optical axis D1 toward the spacecraft S of the telescope 10 and the direction of the projectile F as seen from the telescope 10. You can grasp the relationship with D2. Since the transmission unit 20 is configured to emit the first laser beam L1 in parallel with the optical axis of the telescope 10, the optical axis D1 of the telescope 10 can be regarded as the first laser beam L1. Therefore, the first monitoring area A1 and the second monitoring area A2 can be set to have a shape such as a circle concentric with the optical axis D1 of the telescope 10.

On the other hand, as described above, since the first laser beam L1 is affected by atmospheric fluctuations, it may propagate in a direction different from the emission direction. Therefore, the control unit 40 corrects the emission direction of the first laser beam L1 based on the output of the beam monitor 33, and the first monitoring area A1 and the second monitoring are based on the corrected position of the first laser beam L1. The area A2 is set.

FIG. 16 is a schematic diagram showing the relationship between the altitude from the transmission unit 20 and the size of the first monitoring area A1 and the second monitoring area A2. The control unit 40 sets the first monitoring area A1 and the second monitoring area A2 wider as the projectile F moves away from the transmission unit 20 (the higher the altitude). In the illustrated example, the first monitoring region A1 and the second monitoring region A2 are regions corresponding to the bottom surface of the cone having the beam emission axis of the transmission unit 20 as the axis. As a result, the first monitoring region A1 and the second monitoring region A2 can be appropriately set even when the propagation direction of the first laser beam L1 fluctuates due to atmospheric fluctuations.

Further, also in the case of this example, the shapes and sizes of the first monitoring area A1 and the second monitoring area A2 are, for example, the atmospheric fluctuation information acquired from the seeing monitor 31 and the first laser acquired from the beam monitor 33. It may be dynamically changed based on the information regarding the emission direction of the light L1, the beam spread angle corrected by the execution of the above-mentioned beam control mode, and the like.

When the radar device 62 is configured to transmit the radar in the emission direction of the first laser beam L1, the irradiation range of the radar may be set as the first monitoring area. In this case, when the presence of the flying object F is confirmed by the radar device 62, the control unit 40 generates a control signal for activating the alarm device 80 and a control signal for stopping the transmission of the first laser beam L1, respectively. It may be configured to do so.

FIG. 17 is a sequence diagram showing the operation of each part of the space optical communication device G when the monitoring mode is executed in chronological order.

As shown in FIG. 17, the control unit 40 acquires the outputs of the beam monitor 33 and the monitoring unit 60 at predetermined intervals via the acquisition unit 41 (see FIG. 12), and acquires the outputs of the first monitoring area A1 and the second monitoring area A2. To set. The thermal infrared camera 61, the radar device 62, and the data acquisition device 63 as the monitoring unit 60 each monitor the presence or absence of the flying object F in the sky above the emission direction of the first laser beam L1, and when the presence of the flying object F is confirmed. Information about the position of the flying object F is output to the control unit 40. The control unit 40 continues to transmit the first laser beam L1 from the transmission unit 20 until it detects that the projectile F is approaching the second monitoring region A2. When the control unit 40 acquires information about the projectile F from at least one of the thermal infrared camera 61, the radar device 62, and the data acquisition device 63, the control unit 40 is based on the relative positions of the projectile F and the first laser beam L1. , The alarm device 80 is activated, or the emission of the first laser beam L1 is stopped.

That is, when the control unit 40 determines that the flying object F has passed through the second monitoring area A2 (contact with the boundary line of the second monitoring area A2), the control unit 40 activates the alarm device 80 (hereinafter, also referred to as an alarm signal). Is generated, and this is output to the alarm device 80. As a result, the alarm 80 is activated. With the issuance of the alarm, the transmission of the first laser beam L1 may be stopped by a manual operation by the operator.

On the other hand, when the control unit 40 determines that the flying object F has passed through the first monitoring area A1 (contact with the boundary line of the first monitoring area A1), the control unit 40 stops the transmission of the first laser beam L1 (hereinafter referred to as a control signal). , Also referred to as a laser stop signal) is further generated, and this is output to the transmission unit 20. The transmission unit 20 closes the shutter 224 based on the control signal from the control unit 40, and stops the emission of the first laser beam L1. During this time, the control unit 40 continuously generates an alarm signal.

Then, when the control unit 40 determines that the flying object F has moved to the outside of the second monitoring area A2, the control unit 40 stops the generation of the warning signal and the laser stop signal. As a result, the activation of the alarm device 80 is released, and the shutter 224 is opened to restart the emission of the first laser beam L1. The emission resumption control of the first laser beam L1 may be executed when the projectile F moves to the outside of the first monitoring region A1. Further, the emission resumption control of the first laser beam L1 may be executed after a predetermined time has elapsed after the projectile F has moved to the outside of the second monitoring region A2.

According to the present embodiment, a series of monitoring the relative positions of the first laser beam L1 and the projectile F and stopping the emission of the first laser beam L1 when the projectile approaches the first laser beam L1 by a predetermined value or more. Can be controlled automatically. As a result, it is possible to stop and release the emission of the first laser beam L1 without relying on the operation of the worker.
Further, according to the present embodiment, since the emission direction of the first laser beam L1 can be detected based on the output of the beam monitor 33, the detection accuracy of the emission direction of the first laser beam L1 is improved, and due to atmospheric fluctuations. It is also possible to grasp the fluctuation of the propagation direction of the first laser beam.

FIG. 18 is a flowchart showing an example of the processing procedure of the control unit 40 based on the output of the thermal infrared camera 61.

First, the control unit 40 acquires detection signals from the beam monitor 33 and the thermal infrared camera 61, respectively (step 201). Subsequently, the control unit 40 receives the first laser beam L1 in the XY plane including the field of view of the thermal infrared camera 61 based on the output of the thermal infrared camera 61 (IR camera 1) and the output of the beam monitor 33 (IR camera 2). The position (emission direction) of is calculated (step 202). Since the beam monitor 33 is installed apart from the thermal infrared camera 61 (IR camera 1), the position (emission) of the first laser beam L1 in the XY plane is based on the separation distance on the spatial coordinates of the two. The direction) is corrected (step 203). After that, the control unit 40 sets the first monitoring area A1 and the second monitoring area A2, respectively, based on the corrected position information of the first laser beam L1 (step 204).

Then, the control unit 40 determines the relative positional relationship between the flying object F and the first laser beam L1 (step 205), and generates an alarm signal when the flying object F moves into the second monitoring area A2 (step 205). Step 206), when the projectile F further moves into the first monitoring region A1, a laser stop signal is generated (step 207). The control unit 40 continues to generate the warning signal and the laser stop signal until the projectile F moves to the outside of the first monitoring area A1 and the second monitoring area A2 (step 208).

FIG. 19 is a flowchart showing an example of a procedure for detecting the position of the first laser beam L1 using the output of the beam monitor 33.

The control unit 40 acquires the imaging data of the scattered light L1sx and L1sy of the first laser beam L1 in the atmosphere from the beam monitor 33 (step 301). The control unit 40 is the beam position of the scattered light L1s of the first laser beam L1 on the X-plane and the Y-plane (see FIG. 9) from the image captured by the camera 336 of the beam monitor 33 (the emission direction from the transmission unit 20; the same applies hereinafter). ) Is detected (step 302).

The control unit 40 calculates and determines the two-dimensional coordinates of the first laser light scattered light L1s given from the beam positions of the X-plane and the Y-plane, respectively (steps 303 and 304, FIG. 10). As a result, the propagation direction of the first laser beam L1 on each of the X-plane and the Y-plane can be grasped, and by superimposing these, the position in the sky where the first laser beam L1 is located is three-dimensionally used as a locus. Can be calculated to. The calculated three-dimensional coordinates of the scattered light L1s are used for setting the first monitoring area A1 and the second monitoring area A2 that realize the aircraft security system (step 305).

FIG. 20 is a flowchart showing an example of a processing procedure of the control unit 40 based on the output of the radar device 62.

The control unit 40 acquires information on the azimuth (Az), elevation angle (EL), and distance measurement (RNG) from the radar device 62 (step 401), and further, based on the output of the beam monitor 33, in the beam width of the radar. The position of the first laser beam L1 (transmitted beam Tx) on the X-plane and the Y-plane is calculated (step 402). Next, since the beam monitor 33 is installed at a distance from the radar device 62, the control unit 40 is located at the position of the first laser beam L1 in the XY plane based on the separation distance on the spatial coordinates of the two. The emission direction) is corrected (step 403). Subsequently, the control unit 40 displays the correlation between the first laser beam L1 and the projectile F, that is, the spatial position of the first laser beam L1 and the projectile F on the display unit 70 (step 404), and subsequently. It is determined whether or not the projectile F is in a predetermined space including the first laser beam L1 (step 405).

In this example, the predetermined space is the irradiation range of the radar, the irradiation range of the radar is the first monitoring area A1, and the control unit 40 receives the warning signal and the warning signal until the projectile F is no longer searched from the radar irradiation range. Laser stop signals are generated, respectively (steps 406 and 407). Not limited to this example, the first monitoring area A1 and the second monitoring area A2 may be set in the radar irradiation range.

FIG. 21 is a flowchart showing an example of a processing procedure of the control unit 40 based on the output of the data acquisition device 63.

The control unit 40 acquires information about the projectile F (latitude, longitude, altitude, etc.) from the data acquisition device 63, and acquires information about the optical axis direction of the telescope 10 (direction, elevation angle, etc.) (step 501). Subsequently, the control unit 40 analyzes the three-dimensional positions of the first laser beam L1 and the projectile F from these information (step 502). Since the beam monitor 33 is installed away from the telescope 10, the control unit 40 is located at the position (emission direction) of the first laser beam L1 in the three-dimensional space based on the distance between the two in spatial coordinates. ) Is corrected (step 503). After that, the control unit 40 sets the first monitoring area A1 and the second monitoring area A2, respectively, based on the corrected position information of the first laser beam L1 (step 504).

Then, the control unit 40 determines the relative positional relationship between the flying object F and the first laser beam L1 (step 505), and generates an alarm signal when the flying object F moves into the second monitoring area A2 (step 505). Step 506) When the projectile F further moves into the first monitoring region A1, a laser stop signal is generated (step 507). The control unit 40 continues to generate the warning signal and the laser stop signal until the projectile F moves to the outside of the first monitoring area A1 and the second monitoring area A2 (step 508).

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made.

For example, in the above embodiments, optical communication with a spacecraft has been described as an example, but the present invention is not limited to this. For example, a system (optical satellite distance measurement, active debris observation) that measures the distance between a spacecraft and a ground station with the earth's atmosphere sandwiched between transmission lines, and a laser between the spacecraft and power receiving equipment with the earth's atmosphere sandwiched between transmission lines. The present invention can also be applied to a system (optical energy transmission) or the like that transmits energy by means of. Further, the laser used in the space optical communication device has been described as an infrared laser which is a typical example, but the present invention is not limited to this, and visible light may be used.

Further, in the above embodiment, an example in which the seeing monitor 31, the light receiving intensity monitor 32, and the like are integrally attached to the outer peripheral portion of the telescope 10 has been described, but these detection portions can also be installed inside the telescope. Is. Further, the light receiving intensity monitor may be configured by a light receiving sensor of the downlink laser light focused by the telescope.

Further, in the above embodiment, the beam monitors 33 shown in FIGS. 8 to 11 are used for detecting the emission direction (beam position) of the first laser beam L1, but the present invention is not limited to this, and the emission of the first laser beam L1 is not limited to this. A beam monitor having another configuration capable of detecting the direction may be adopted.

Further, as an embodiment, the status (shutter open / close) of the shutter 224 of the first laser beam L1 may be notified by image display and / or sound, and may be provided with a notification device and a recording device so as to record as a log. good.

10 ... Telescope 20 ... Transmitter 31 ... Seeing monitor 32 ... Light receiving intensity monitor 33 ... Beam monitor 40 ... Control unit 60 ... Monitoring unit 61 ... Thermal infrared camera 62 ... Radar device 63 ... Data acquisition device G ... Spatial optical communication device A1 ... 1st monitoring area A2 ... 2nd monitoring area L1 ... 1st laser beam (uplink)
L2 ... 2nd laser beam (downlink)
S ... Spacecraft

Claims (11)

A transmitter that transmits the first laser beam to the spacecraft,
A receiving unit that receives the second laser beam transmitted from the spacecraft, and
A monitoring unit that monitors a flying object flying over the emission direction of the first laser beam,
A beam monitor that detects the emission direction of the first laser beam from the transmitting unit, and
When a first monitoring area for partitioning the periphery of the first laser beam is set based on the output of the beam monitor, and the entry of the projectile into the first monitoring area is determined based on the output of the monitoring unit. A spatial optical communication device including a control unit that generates a control signal for stopping the transmission of the first laser beam. The spatial optical communication device according to claim 1.
The control unit is a spatial optical communication device that sets the first monitoring area wider as the flying object moves away from the transmission unit. The spatial optical communication device according to claim 1 or 2.
Equipped with an alarm
The control unit further sets a second monitoring area that partitions the periphery of the first monitoring area, and outputs a control signal for activating the alarm when the flying object is determined to enter the second monitoring area. Spatial optical communication device to generate. The spatial optical communication device according to any one of claims 1 to 3.
The beam monitor has a camera unit that captures scattered light of the first laser beam in the atmosphere.
The camera unit is a spatial optical communication device that acquires an image of the scattered light observed from two directions intersecting each other at a predetermined angle. The spatial optical communication device according to any one of claims 1 to 4.
The monitoring unit is a spatial optical communication device including a plurality of monitoring devices having different monitoring distances. The spatial optical communication device according to claim 5.
The monitoring unit is a spatial optical communication device including a thermal infrared camera. The spatial optical communication device according to claim 5.
The monitoring unit is a spatial optical communication device including a radar device. The spatial optical communication device according to claim 5.
The monitoring unit is a spatial optical communication device including a receiving device that receives identification information transmitted from the flying object. The spatial optical communication device according to any one of claims 1 to 8.
A spatial optical communication device further comprising a display unit capable of displaying the relative positional relationship between the first laser beam, the flying object, and the first monitoring region. The spatial optical communication device according to any one of claims 1 to 9.
A seeing monitor having a light receiving surface for receiving the second laser beam and detecting fluctuations in the atmosphere on the propagation path of the second laser beam is further provided.
The control unit is a spatial optical communication device that sets the size of the first monitoring area based on the output of the seeing monitor. The spatial optical communication device according to any one of claims 1 to 10.
A light receiving intensity monitor for detecting the light receiving intensity of the second laser beam is further provided.
The control unit is a spatial optical communication device that generates a control signal for controlling the spread angle and power of the first laser beam based on the output of the light receiving intensity monitor.

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