WO2020080373A1 - Optical ground station operational management system, optical operation planning device, and optical ground station operational management method and program - Google Patents

Abstract

This optical ground station operational management system 1 includes: a low-level cloud monitoring and determining device 15 which acquires cloud image data within a field of view, draws a predictive orbital arc within the field of view of a probe 5 that connects an optical link with an optical ground station 2, and determines a cloud occupation ratio in the predictive orbital arc within the field of view by superimposing the predictive orbital arc within the field of view onto the cloud image data within the field of view; a high-level cloud monitoring and determining device 22 which acquires cloud image data on a wide area from a meteorological satellite 4a, draws a predictive orbital arc of the probe 5 in a wide area, and determines a cloud occupation ratio in the predictive orbital arc of the wide area by superimposing the predictive orbital arc of the wide area onto the cloud image data for the wide area; and an optical operation planning device 30 which assess, on the basis of the determination results, a cloud occupation ratio obtained by overlapping the low-level clouds and the high-level clouds in the predictive orbital arc of the probe 5, and manages and controls operation planning of the optical ground station 2 on the basis of the assessment result.

Description

Optical ground station operation management system, optical operation planning device, optical ground station operation management method and program

The present invention relates to an optical ground station operation management system, an optical operation planning device, an optical ground station operation management method, and a program for managing the operation of a system that downlinks data by optical communication from a spacecraft such as a spacecraft to an optical ground station. Regarding

In space-to-ground optical communication, not only the effects of atmospheric fluctuations that occur when a laser passes through the atmosphere, but also when a cloud enters the transmission section, the laser is blocked and communication cannot be established. For this reason, a station distribution technology (Site Diversity) is required to disperse multiple optical ground stations in locations where annual cloud occupancy is uncorrelated. However, it is extremely rare that a cloud does not always occur, and by some method, data from the spacecraft is switched by avoiding clouds so that the link is not broken when the cloud enters the transmission section. Downlink efficiency needs to be improved.

In Non-Patent Document 1, the optical ground station is added to the station dispersion technology (Site Diversity), the cloud image captured from the satellite is analyzed, and the location where the cloud blocking between the spacecraft and the optical ground station is small is selected and the light is selected. A technique for selecting a ground station is disclosed.

At present, a mechanism for avoiding clouds has not been fully established, and when using a laser in the atmosphere like optical communication between space and ground, it is possible to actually use clouds only with local dispersion technology (Site Diversity). The operation will be suspended if a vehicle enters. According to the knowledge of the present inventors, even if the technology disclosed in Non-Patent Document 1 is applied to the local distribution technology (Site Diversity), it is considered that there is a high possibility that an operation suspension will occur due to the entry of clouds.

In view of the above circumstances, an object of the present invention is to provide an optical ground station operation management system, an optical operation planning device, an optical ground station operation management method and a program capable of more efficiently managing the operation of the optical ground station. To do.

In order to achieve the above object, an optical ground station operation management system according to an aspect of the present invention includes a low-layer cloud monitoring / determining device, a high-layer cloud monitoring / determining device, and an optical operation planning device.
The low-level cloud monitoring and discriminating device takes in cloud image data in the field of view, draws an expected orbit arc in the field of view of a spacecraft connecting an optical link with the optical ground station, and creates cloud image data in the field of view. The cloud occupancy ratio of the predicted orbit arc in the visual field is determined by superposing the predicted orbit arcs in the visual field.
The high-level cloud monitoring / discriminating apparatus captures wide-area cloud image data, draws an expected orbit arc of the spacecraft in the wide area, and superimposes the wide-area expected orbit arc on the wide-area cloud image data to predict the wide area. Determine the cloud occupancy of the orbit arc.
The optical operation planning device superimposes a low cloud and a high cloud of the expected orbit arc of the spacecraft on the basis of the result of the determination by the low cloud monitoring and determining device and the result of the determination by the high cloud monitoring and determining device. The cloud occupancy ratio is determined, and the operation plan of the optical ground station is managed and controlled based on the determination result.

In an optical ground station operation management system according to an aspect of the present invention, a low cloud and a high cloud of a predicted spacecraft orbit arc are calculated based on a cloud occupancy ratio of the predicted orbit arc in the field of view and a cloud occupancy ratio of the predicted orbit arc in a wide area. The cloud occupancy ratio is determined by superimposing and, and the operation plan of the optical ground station is managed based on the result of the determination of the cloud occupancy ratio by superimposing the low-rise clouds and high-rise clouds of the expected orbit arc of the spacecraft. Control. That is, for example, cloud images taken from meteorological satellites can mainly be used to understand only high-level clouds, but in the present invention, high-level clouds and low-level clouds are superposed using predicted orbit arcs of spacecraft on the ground side and satellite side. To determine the cloud occupancy on the spacecraft's expected orbit arc. The cloud occupancy ratio thus determined is a more accurate value, and the operation plan of the optical ground station is managed based on it, so that the operation of the optical ground station can be managed more efficiently.

In the optical ground station operation management system according to an aspect of the present invention, the low-level cloud monitoring / discriminating apparatus divides the predicted orbit arc in the field of view into two or more sections, and calculates the cloud occupancy ratio of the predicted orbit arc for each section. Judgment, the cloud occupancy ratio of the predicted orbit arc for each section and the total cloud occupancy ratio of the predicted orbit arc of each section are output to the optical operation planning device as a result of the judgment by the low-level cloud monitoring and determination device, The high-rise cloud monitoring / discriminating apparatus divides the predicted orbit arc of the wide area into two or more sections, judges the cloud occupancy rate of the predicted orbit arc for each section, and determines the cloud occupancy rate of the predicted orbit arc for each section and each. The cloud occupancy ratio of the total expected orbit arc of the section may be output to the optical operation planning device as a result of the determination by the high-rise cloud monitoring determination device. As a result, it is possible to more accurately determine the cloud approach to the expected orbit arc and more efficiently manage the operation of the optical ground station.

In the optical ground station operation management system according to an aspect of the present invention, the high-rise cloud monitoring / determining device determines, based on the wide-area cloud image data, whether or not the cloud adjacent to the wide-area predicted orbit arc is closer to the predicted orbit arc. 1 arrival forecast information is generated and the first arrival forecast information is output to the optical operation planning apparatus, and the optical operation planning apparatus also operates the optical ground station in consideration of the first arrival forecast information. You may manage the plan. Further, the low-level cloud monitoring / discriminating device creates second arrival forecast information of a cloud adjacent to the predicted orbit arc in the field of view on the basis of cloud image data in the field of view, the second arrival forecast information. The second arrival forecast information may be output to the optical operation planning apparatus, and the optical operation planning apparatus may manage the operation plan of the optical ground station in consideration of the second arrival forecast information. As a result, it is possible to more accurately determine the cloud approach to the expected orbit arc and more efficiently manage the operation of the optical ground station.

In the optical ground station operation management system according to an aspect of the present invention, the optical operation planning device accumulates any one of the cloud occupancy rates, and also adds the accumulated cloud occupancy rate to the operation plan of the optical ground station. May be managed. As a result, it is possible to more accurately determine the cloud approach to the expected orbit arc and more efficiently manage the operation of the optical ground station.

In the optical ground station operation management system according to an aspect of the present invention, the optical ground station is provided, acquires position information of an aircraft within the field of view of the optical ground station, and outputs an operation stop message based on the position information. The optical operation planning apparatus further includes an operation stop message transfer unit for transmitting to the operation planning apparatus, and the optical operation planning apparatus manages the operation plan of the optical ground station in consideration of the operation stop message transferred from the operation stop message transfer unit. May be. As a result, for example, it is possible to avoid the downlink service from being stopped for a certain period of time or more from the spacecraft and improve the downlink efficiency.

In the optical ground station operation management system according to an aspect of the present invention, the low-layer cloud monitoring discriminating apparatus, the high-layer cloud monitoring discriminating apparatus, and the optical operation planning apparatus, for each of the plurality of optical ground stations arranged in different areas. The optical operation planning device is installed for each optical ground station, determines the cloud occupancy ratio of the low altitude cloud and the high altitude cloud of the expected orbit arc of the spacecraft for each optical ground station, and determines the orbital arc of the spacecraft. It is more preferable to manage an operation plan in which stations with good conditions are sequentially selected from a plurality of the optical ground stations based on the result of the overlapping state with and are operated.

In the optical ground station operation management system according to an aspect of the present invention, the optical operation planning device takes in an orbit forecast value of the spacecraft, and performs an initial operation of sequentially operating the plurality of optical ground stations based on the orbit forecast value. A plan is created and transferred to each of the optical ground stations, and at least one of the plurality of optical ground stations has a cloud occupancy rate in which a low cloud and a high cloud of the predicted orbit arc of the spacecraft are superimposed on each other exceeding a predetermined threshold value. In this case, it is more preferable to execute the process of changing the initial operation plan and transfer the changed operation plan to each optical ground station.

In an optical ground station operation management system according to an aspect of the present invention, at least data exchange between the low-level cloud monitoring and determining device and the optical operation planning device and the high-level cloud monitoring and determining device and the optical operation planning device It is preferable to exchange data between them in the form of messages. As a result, the amount of data exchanged between the respective parts can be reduced, and more rapid operation is possible.

In the optical ground station operation management system according to an aspect of the present invention, the spacecraft downlinks data to the optical ground station by optical communication.

An optical operation planning apparatus according to an aspect of the present invention, based on cloud occupancy information by a low-layer cloud monitoring and discriminating apparatus and cloud occupancy information by a high-layer cloud monitoring and discriminating apparatus, occupies low- and high-layer clouds with respect to an expected orbit arc of a spacecraft. A control unit for determining the ratio and managing the operation plan of the optical ground station based on the determined result is provided.

An optical ground station operation management method according to an aspect of the present invention, cloud image data in the field of view near the optical ground station is captured, in the field of view of the spacecraft that connects an optical link with the optical ground station. Draw an expected orbit arc, superimpose the expected orbit arc in the field of view on the cloud image data in the field of view to determine the cloud occupancy rate of the expected orbit arc in the field of view, and capture wide-area cloud image data, Draw an expected orbit arc in the wide area of the aircraft, superimpose the wide area expected orbit arc on the wide area cloud image data to determine the cloud occupancy rate of the wide area expected orbit arc, and within the determined field of view. Based on the cloud occupancy ratio of the predicted orbit arc and the cloud occupancy ratio of the wide area of the predicted orbit arc, the cloud occupancy ratio of the low altitude cloud and the high altitude cloud of the predicted orbit arc of the spacecraft is determined, and the result of the determination is determined. Manage and control the operation plan of the optical ground station based on .

A program according to an aspect of the present invention captures cloud image data in a field of view near an optical ground station and draws an expected orbit arc in the field of view of a spacecraft that connects an optical link with the optical ground station. The step of inputting the result of determining the cloud occupancy ratio of the predicted orbit arc in the field of view by superimposing the predicted orbit arc in the field of view on the cloud image data in the field of view, and capturing wide area cloud image data, Drawing a predicted orbit arc in the wide area of the spacecraft, and inputting the result of determining the cloud occupancy ratio of the wide area predicted orbit arc by superimposing the wide area predicted orbit arc on the wide area cloud image data, Based on the input cloud occupancy ratio of the predicted orbit arc in the field of view and the cloud occupancy ratio of the predicted orbit arc of the wide area, the cloud occupancy ratio of the low altitude cloud and the high altitude cloud of the predicted orbit arc of the spacecraft is determined. And the step To perform the steps on a computer that manages and controls the operation plan of Chu machine anticipated trajectory arc the optical ground station based on the lower clouds and altostratus to the results to determine the cloud occupancy superimposed a.

According to the present invention, the operation of the optical ground station can be managed more efficiently.

It is a figure for explaining the outline of the optical ground station operation management system concerning one embodiment of the present invention. It is a figure which shows schematic structure of the optical ground station operation management system which concerns on one Embodiment. It is a block diagram which shows the structure of the low-rise cloud monitoring discrimination system which concerns on one Embodiment. It is a flow chart which shows operation of the low-rise cloud monitoring discrimination device concerning one embodiment. It is a figure which shows an example of the image which overlapped the forecasted trajectory arc on the cloud image in the visual field which concerns on one Embodiment. It is a table which shows the information of the cloud occupancy ratio transmitted from the low-rise cloud monitoring discrimination device which concerns on one Embodiment to an optical operation planning apparatus. It is a block diagram which shows the structure of the high-rise cloud monitoring discrimination system which concerns on one Embodiment. It is a flowchart which shows operation | movement of the high-rise cloud monitoring discrimination device which concerns on one Embodiment. It is a figure which shows an example of the image which overlapped the expected orbit arc on the cloud image of a wide area which concerns on one Embodiment. It is a table which shows the information of the cloud occupancy ratio transmitted from the high-rise cloud monitoring discrimination device which concerns on one Embodiment to an optical operation planning device. It is a figure which shows an example of the cloud which exists in the atmosphere. It is a figure which shows the structure on the network in the optical ground station operation management system which concerns on one Embodiment. It is a flow chart which shows operation of the optical operation planning device concerning one embodiment. 6 is a table showing an example of operation plan information transmitted from the optical operation planning apparatus of the master station to each optical operation planning apparatus and the optical ground station according to an embodiment. It is a figure for explaining judgment of whether there is a changeable optical ground station concerning one embodiment. It is a figure which shows the example of the allocation plan state which concerns on one Embodiment. It is a state of each optical ground station according to one embodiment. 6 is a timing chart showing data exchange between respective units in the initial operation plan according to the embodiment. 7 is a timing chart showing an exchange of data between respective units in a plan change according to an embodiment.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining an outline of an optical ground station operation management system according to an embodiment of the present invention.
As shown in FIG. 1, the optical ground station operation management system according to this embodiment manages an optical operation plan of a plurality of optical ground stations 2 (2a, 2b, 2c). Here, the optical ground stations 2a, 2b, 2c are typically installed in three different regions on the earth, such as Asia Pacific, Europe, and North America. In three regions of Asia Pacific, Europe, and North America, meteorological satellites 4a, 4b, and 4c observe clouds. Reference numeral 5 in FIG. 1 is a spacecraft for exploring Mars or the like, and downlinks data such as imaging data from the spacecraft 5 to the optical ground stations 2a, 2b, 2c by optical communication. In FIG. 1, the optical ground station 2a in the Asia-Pacific region receives data from the spacecraft 5. However, the data from the spacecraft 5 is received in accordance with the operation plan and control of the optical ground station operation management system according to this embodiment. The optical ground station that receives the signal is switched from the optical ground station 2a to the other optical ground stations 2b and 2c. Hereinafter, the optical ground station 2a will be mainly described, but the other optical ground stations 2b and 2c have the same configuration unless otherwise described.

The spacecraft 5 is provided with a camera for capturing an object to be probed such as Mars, a memory for storing the imaged data, and a communication unit for transmitting (downlink) the data in the memory to the optical ground stations 2a, 2b, 2c. .
The spacecraft is not limited to the spacecraft, and also includes a structure having a communication function capable of moving in outer space such as an artificial satellite other than the spacecraft and a space station. The artificial satellites are geostationary satellites that orbit (GEO: Geostationary Earth Orbit), low earth orbit (LEO) and medium orbit (MEO: Medium Earth Orbit), regardless of the rotation period of the earth. It also includes artificial satellites that fly in deep space. That is, the altitude from the surface of the spacecraft is not particularly limited. The artificial satellites are typically meteorological satellites, communication satellites, etc., but may be launched for any purpose.

FIG. 2 is a diagram showing a schematic configuration of an optical ground station operation management system according to this embodiment.
As shown in FIG. 2, the optical ground station operation management system 1 is mainly composed of a low-rise cloud monitoring / discrimination system 10, a high-rise cloud monitoring / discrimination system 20, and an optical operation planning device 30. The low-level cloud monitoring / determining system 10, the high-level cloud monitoring / determining system 20, and the optical operation planning device 30 are arranged in the optical ground stations 2a, 2b, and 2c, respectively.

The low-level cloud monitoring / discrimination system 10 takes in cloud image data in the field of view, draws an expected orbit arc in the field of view of a spacecraft connecting an optical link with the optical ground station 2a, and draws cloud image data in the field of view. Then, the expected orbit arcs in the field of view are overlapped with each other to determine the cloud occupancy ratio of the expected orbit arcs in the field of view.
The low-rise cloud monitoring / discrimination system 10 is arranged near the optical ground station 2a. Typically, the low-level cloud monitoring / discrimination system 10 is arranged in the same site as the optical ground station 2a (for example, near a telescope) and looks up from the optical ground station 2a (a low-level cloud in this specification). (Also called)) or its movement. The information on the cloud occupancy ratio (hereinafter, also referred to as a cloud occupancy message) for the low-layer cloud created by the low-layer cloud monitoring / discrimination system 10 is transmitted to the optical operation planning apparatus 30 via the communication network.

The high-level cloud monitoring / discrimination system 20 takes in wide-area cloud image data, draws the expected wide-area orbit arc of the probe 5, and superimposes the wide-area expected orbit arc on the wide-area cloud image data to create the wide-area cloud image data. Determine the cloud occupancy of the expected orbit arc.
The high-level cloud monitoring / discrimination system 20 receives wide-area cloud image data (full disk image) in the Asia-Pacific region from the weather satellite 4a via the weather data center 6a and the communication network. The meteorological satellite 4a is located in an orbit around the earth or in a geostationary orbit, and monitors the presence or absence of a cloud (also referred to as a high-level cloud in this specification) overlooking the earth from the meteorological satellite 4a and its movement. The information on the cloud occupancy ratio (hereinafter, also referred to as a cloud occupancy message) about the high-rise clouds created by the high-rise cloud monitoring / discrimination system 20 is transmitted to the optical operation planning apparatus 30 via the communication network.

The optical operation planning device 30 is composed of a computer in which a program for executing the optical ground station operation management described below is installed. The optical operation planning device 30 determines the cloud occupancy ratio in which the low cloud and the high cloud of the expected orbit arc of the spacecraft 5 are superimposed on the basis of the cloud occupancy message for the low cloud and the cloud occupancy message for the high cloud, and the like. The optical ground station 2a, 2b, 2c is provided with a control unit for creating an optical operation plan for managing the operation plan. The optical operation plan created by the optical operation planning device 30 is transmitted to the optical ground station 2a or the like via the communication network.

The optical ground station 2a receives the imaging data and the like stored in the memory of the probe 5 from the probe 5 by optical communication according to the optical operation plan by downlink. The optical ground station 2a obtains data on the approach of the aircraft 8 from the nearby radar 7, and based on this data, the laser light emitted from the optical ground station 2a to the probe 5 is not irradiated to the aircraft 8. A laser beam is blocked by a shutter function (not shown).
In this case, the radar 7 functions as an operation stop message transmission unit that acquires position information of the aircraft 8 within the field of view of the optical ground station 2a and transfers an operation stop message to the optical operation planning device 30 based on the position information. The optical operation planning device 30 manages the operation plan of the optical ground station 2a by adding the operation stop message transmitted from the radar 7 (planning, correction, execution, etc. of the optical operation plan).
The operation stop message transmission unit determines whether or not the aircraft 8 approaches the expected orbit arc of the spacecraft 5 based on, for example, the position or course of the aircraft 8 navigating above the optical ground station 2a. When it is determined that the vehicle approaches the area connecting the spacecraft 5 and the optical ground station 2a, an operation stop message is generated and transmitted to the optical operation planning apparatus 30. In this case, the operation stop message may be generated when the approach distance of the spacecraft 5 to the expected orbit arc becomes equal to or less than the predetermined distance. Alternatively, depending on the size of the predetermined distance, the operation stop message may be generated after a predetermined time has elapsed after the distance becomes the predetermined distance or less.

In the following, the optical ground station operation management system 1 provided in each optical ground station 2a, 2b, 2c may be described as reference numerals 1a, 1b, 1c, respectively. Further, the optical operation planning apparatus 30 provided in each optical ground station 2a, 2b, 2c may be described as the optical operation planning apparatus 30a, 30b, 30c, respectively. Further, the meteorological data centers 6 provided in the respective ground stations 2a, 2b, 2c are referred to as meteorological data centers 6a, 6b, 6c (see FIG. 1).

As shown in FIG. 2, the optical operation planning device 30a, 30b, 30c exchanges an optical operation plan and a cloud occupancy message (information of low-level clouds and information of high-level clouds are superimposed) via a communication network. Be seen. As will be described later, the cloud occupancy message includes the ratio of clouds (cloud occupancy ratio) to the predicted orbit arc of the searcher 5 within the field of view of the low-rise cloud monitoring / discrimination system 10.

FIG. 3 is a block diagram showing the configuration of the low-rise cloud monitoring / determining system 10.
As shown in FIG. 3, the low-rise cloud monitoring / discrimination system 10 is equipped with a fisheye lens having a viewing angle of 180 degrees, an infrared camera 11 for capturing cloud image data in the field of view, a visible camera 12, and a heater 13 for temperature compensation. A PC 14 that controls the infrared camera 11 and the visible camera 12 and takes in image data. The infrared camera 11 has a fish-eye lens (not shown) and an image sensor that captures infrared rays (for example, infrared rays having a wavelength of 10.4 μm) emitted from water vapor (cloud). The visible camera 12 may be installed arbitrarily and may be omitted if necessary. Further, the low-rise cloud monitoring / determining system 10 may further include a fan (not shown) for temperature compensation.
Further, the low-layer cloud monitoring / determining system 10 creates a cloud occupancy message for the low-level cloud from the PC 14 based on image data and the like, and transmits the cloud-occupancy message to the optical operation planning device 30 via the communication network. A device 15 is provided.

FIG. 4 is a flowchart showing the operation of the low-rise cloud monitoring / determining device 15.
The low-level cloud monitoring / determining device 15 takes in cloud image data within the field of view from the PC 14 (step 401), and stores the cloud image data within the field of view as data for analysis (step 402). The cloud image data in the field of view is typically image data in the field of view of a fisheye lens (infrared camera 11) capable of capturing a range (entire sky) from the zenith of the sky to the horizon (360 degrees). The cloud image data in the field of view is low-level cloud data.
Next, the low-level cloud monitoring / determining device 15 takes in the orbit forecast value of the spacecraft 5 from a predetermined site or the optical operation planning device 30 via the communication network, and draws the expected orbit arc of the spacecraft 5 within the field of view. (Step 403).
Next, the low-level cloud monitoring / determining device 15 superimposes the predicted orbit arc within the field of view on the cloud image data within the field of view (step 404). FIG. 5 shows an example thereof.

Next, as shown in FIG. 5, the low-level cloud monitoring / determining device 15 divides the area overlapping the predicted orbit arc in the field of view into, for example, three sections B1, B2, and B3, and calculates the cloud occupancy ratios of the sections B1 to B3. It is determined (step 405). In the sections B1 to B3, the imaging data of the infrared camera acquired via the fisheye lens is used to indicate the moving direction of the spacecraft 5 along the predicted orbit arc (indicated as an arrow from northeast to northwest in FIG. 5). The area of FIG. 5 is an area that is partitioned along a line, and the example of FIG. 5 illustrates an example in which the section B1, the section B2, and the section B3 are sequentially partitioned from the southeast to the northwest in an arbitrary angle range. The orbital arc to be divided is not limited to 3 sections and may be 2 sections or 4 sections or more. The sections B1 to B3 correspond to the sections obtained by further dividing a part of the section B into the section B in the high frequency image data shown in FIG.

The low-rise cloud monitoring / determining device 15 determines the presence / absence of a cloud based on the output information of each pixel of the cloud image data. For example, the low-level cloud monitoring / determining device 15 determines the presence / absence of a cloud based on information such as the brightness or temperature of each pixel of image data.
In the present embodiment, the cloud occupancy ratio with respect to the predicted orbit arc is the first pixel number, which is the total number of pixels to which the predicted orbit arc belongs, and the second pixel number, which is the total number of pixels that the cloud occupies among the first pixel number. It is calculated by the ratio of the second pixel number to the one pixel number ((second pixel number / first pixel number) × 100 [%]).
In the section to which the explorer 5 belongs (section B1 in the example of FIG. 5), the first pixel number is from the current position of the explorer 5 on the expected orbit arc to the predicted orbit arc of the section to which the explorer belongs. It is the total number of pixels to the end, and gradually decreases as the probe 5 moves. On the other hand, in the section to which the spacecraft 5 does not belong (section B2 and section B3 in the example of FIG. 5), the total number of pixels occupied by the predicted orbit arc in each section.

The low-level cloud monitoring / determining device 15 outputs, as a cloud occupancy message, information on the cloud occupancy ratios of the three sections B1 to B3 and their total to the optical operation planning device 30 (step 406). FIG. 6 shows an example of the cloud occupation message CM1 transmitted from the low-rise cloud monitoring / determining device 15 to the optical operation planning device 30. The cloud occupancy message CM1 is created in a message format (for example, text format) as shown in FIG. 6, showing the cloud occupancy rate of each section and the cloud occupancy rate of all sections at the present time.

The low level cloud monitoring / determining device 15 repeats the above processing (steps 401 to 406) in a predetermined cycle. As a result, it is possible to acquire the temporal change of the cloud occupancy rate corresponding to the position of the spacecraft 5 and the movement of the cloud, which changes every moment. The predetermined cycle is not particularly limited, and may be, for example, 5 minutes, 10 minutes, 30 minutes or more. Further, by repeating the above processing at a predetermined cycle, the data of the cloud occupancy ratio corresponding to the position of the spacecraft 5 and the movement of the cloud which change every moment may be updated or overwritten.

In addition, the low-level cloud monitoring / determining device 15 determines the predicted orbit arc that can be understood from the cloud image data in the field of view and the optical design (lens viewing angle, focal length, sensor size, number of pixels, etc.) of the observation sensor (such as the infrared camera 11). In the outer observation region, arrival forecast information (second arrival forecast information) of the low cloud approaching from the outside of the forecast orbit arc to the forecast orbit arc is created, and the arrival forecast information is sent to the optical operation planning device 30. It can also be configured to output. The arrival forecast information is created, for example, based on the presence or absence of low-level clouds in the observation region outside the expected orbit arc of the spacecraft 5. In this case, the optical operation planning device 30 manages the operation plan of the optical ground station 2a by taking the arrival forecast information into consideration. For example, the optical operation planning apparatus 30 manages operations related to network switching judgment and control of the optical ground stations 2a, 2b, 2c using arrival forecast information of low-layer clouds (for example, modifying the planned optical operation plan). By doing so, it is possible to manage the operation based on the near-real-time prediction by the prefetching process.

FIG. 7 is a block diagram showing the configuration of the high-rise cloud monitoring / determining system 20.
As shown in FIG. 7, the high-level cloud monitoring / discrimination system 20 receives a wide area cloud image data (full disk image) from the meteorological satellite 4a via the meteorological data center 6 and a communication network, and stores the meteorological satellite data server 21. Equipped with. The high-rise cloud monitoring / discrimination system 20 also creates a cloud occupancy message for the high-rise cloud based on the image data from the data server 21 and sends the cloud occupancy message to the optical operation planning apparatus 30 via the communication network. The cloud monitoring and discrimination device 22 is provided.

FIG. 8 is a flowchart showing the operation of the high-rise cloud monitoring / determining device 22.
The high-level cloud monitoring / determining device 22 fetches full-disk infrared observation information (wide area) in the Asia-Pacific region from the meteorological satellite data server 21 (step 801). A wide area is an area on the earth that is typically visible from one meteorological satellite (see FIG. 9).
Next, the high-level cloud monitoring / determining device 22 creates a full-disk infrared cloud image (wide area) from the acquired infrared observation information and outputs it as image data (step 802).
The high-rise cloud monitoring / determining device 22 repeats the above-described processing (steps 801 to 802).
The high-rise cloud monitoring / determining device 22 may be configured to be able to acquire not only an infrared cloud image but also a visible cloud image.

Next, the high-level cloud monitoring / determining device 22 takes in the output image data (step 803), and takes in the orbit forecast value of the spacecraft 5 from a predetermined site or the optical operation planning device 30 via the communication network, and the wide area concerned. Draw the expected orbit arc of the spacecraft 5 at (step 804).
Next, the high level cloud monitoring / determining device 22 superimposes the predicted orbit arc in the wide area on the wide area cloud image data (step 805). FIG. 9 shows an example thereof.

The high-rise cloud monitoring / determining device 22 determines the presence / absence of a cloud based on the information such as the brightness or temperature of each pixel of the cloud image data in a wide area. As shown in FIG. 9, the high-level cloud monitoring / determining device 22 divides the area overlapping the predicted orbit arc in the infrared cloud image of the wide area into, for example, three sections A to C, and the cloud occupancy ratio of each section A to C. Is determined (step 806) and the forecasting process is executed (step 807). The orbital arc to be divided is not limited to 3 sections and may be 2 sections or 4 sections or more.

Sections A to C are areas obtained by dividing the wide-area infrared cloud image along the moving direction of the spacecraft 5 along the expected orbit arc (shown as an arrow from southeast to northwest in FIG. 9). In the example of, the section A, the section B, and the section C are sequentially divided from the southeast to the northwest in a predetermined angle range viewed from the meteorological satellite 4a. In section B, in addition to high clouds, low clouds existing from section B2 to section B3 in FIG. 5 are confirmed.
The method of calculating the cloud occupancy rate is the same as the method of calculating the cloud occupancy rate executed by the low-rise cloud monitoring / determining device 15 described above, and thus detailed description thereof will be omitted. In this case, a data complement process for adjusting the resolution between the low-level cloud image data acquired by the low-level cloud monitoring / determining device 15 and the wide-area cloud image data acquired by the high-level cloud monitoring / determining device 22, or the resolution. The conversion process may be performed.
In the forecasting process, cloud position change for each predetermined time (for example, 10 minutes) and cloud forecast information (speed, direction, arrival time) and warning information are created from the mesh definition at intervals of 2 km, for example. Here, the arrival time means the time from the present until the cloud shields the optical transmission line (optical communication link) between the optical ground station 2a and the probe 5.

Next, the high-rise cloud monitor / discrimination device 22 outputs, as a cloud occupancy message, information on the cloud occupancy ratios of the three sections A to C and their total, and forecast information to the optical operation planning device 30 (step 808). FIG. 10 shows an example of the cloud occupation message CM2 transmitted from the high-rise cloud monitoring / determining device 22 to the optical operation planning device 30. The cloud occupation message CM2 is created in a message format (for example, text format) as shown in FIG.

The high-level cloud monitoring / determining device 22 repeats the above processing (steps 803 to 808) in a predetermined cycle. As a result, it is possible to acquire the temporal change of the cloud occupancy rate corresponding to the position of the spacecraft 5 and the movement of the cloud, which changes every moment. The predetermined cycle is not particularly limited, and is typically the same cycle (for example, 10 minutes, 30 minutes, 1 hour, or more) as the processing (FIG. 4) in the above-described low-level cloud monitoring / discriminating apparatus 15. Is.

The optical operation planning apparatus 30 determines whether or not the cloud blocks the optical communication link between the universe and the ground based on the cloud occupancy ratios (cloud occupancy messages CM1 and CM2) in the sections A to C thus divided. Check each of the above sections along the communication time axis with 5. As a result, it becomes possible to avoid clouds by finely judging in advance whether or not there is a blockage due to cloud occupancy in each section with respect to the direction of travel of the spacecraft, and it is possible to secure a longer communication time for data transfer from the spacecraft 5 to each optical ground. It is possible to realize station selection and network switching control between stations. As a result, the space-to-ground optical communication link can flexibly transfer data without being blocked by clouds. It should be noted that this section setting can be changed depending on the region difference or the cloud occupancy situation that differs depending on the cloud type, and the judgment can be made more sophisticated.

Also, not only the cloud occupancy rate for each of the three sections A to C, but also the total thereof can be used, for example, as the total cloud occupancy rate on the time axis of the optical communication link. For example, for each section, only the evaluation for each section can be performed, and the detailed correspondence for each section can be determined, but the past section may not be meaningful due to the movement of the spacecraft 5. On the other hand, if the total value of the cloud occupancy ratios of all the sections is known at the same time, it is possible to determine the switching of the optical ground station with a bird's-eye view of the entire value by the total value for each traveling time.

Further, the forecast information can be used, for example, as an intrusion prediction from the outside of the orbital arc of the spacecraft 5 and an approach to the orbital arc of another cloud that is difficult to observe due to the limited observation area in the cloud observation device on the ground.
In the present embodiment, the high-rise cloud monitoring / determining device 22 provides arrival forecast information (first arrival forecast information) to the predicted orbit arc of a cloud close to the predicted orbit arc of the wide area based on the cloud image data of the wide area. It is created and the arrival forecast information is output to the optical operation planning device 30. In this case, the optical operation planning device 30 manages the operation plan of the optical ground station 2a by taking the arrival forecast information into consideration.
This enables ground observation to determine the switching between optical ground stations for avoiding clouds that can be used to predict the approach of other clouds outside the field of view to the orbit arc, and disruption of optical communication links due to clouds. It is possible to further reduce the opportunities and improve the data transmission service between space and ground stations.

As shown in FIG. 11, there are various types of clouds at various altitudes in the atmosphere between the optical ground station 2 and the spacecraft 5. The optical ground station operation management system 1 according to the present embodiment is provided with the low-rise cloud monitoring / determining device 15 and the high-rise cloud monitoring / determining device 22 having the above-described configurations, so as to determine the presence or absence of clouds of various altitudes from the ground and space. Can be determined.

The optical operation planning apparatus 30 superimposes the low-rise clouds and high-rise clouds of the expected orbit arc of the spacecraft on the basis of the result determined by the low-rise cloud monitoring determination apparatus 15 and the result determined by the high-rise cloud monitoring determination apparatus 22. The occupation ratio is determined, and the operation plan of the optical ground station 2 is managed according to the determination result. Here, to determine the cloud occupancy ratio in which the low cloud and the high cloud are superposed, the cloud occupancy ratio for the low cloud and the cloud occupancy ratio for the high cloud are used for each section, whichever has the higher cloud occupancy ratio. It means to do.

Typically, the optical operation planning device 30 draws up an initial operation plan of the optical ground station 2, and based on the result determined by the above low-level cloud monitoring determination device 15 and the result determined by the high-level cloud monitoring determination device 22. Based on this, the plan will be revised accordingly. Then, the optical ground station operation management system 1 according to the present embodiment performs network switching control between the optical ground stations 2 based on the plan. This point will be described in more detail below.

FIG. 12 is a diagram showing the configuration on the network in the optical ground station operation management system 1 according to the present embodiment.
In FIG. 12, reference numeral 1a indicates an optical ground station operation management system for an Asia Pacific organization, reference numeral 1b indicates an optical ground station operation management system for a European organization, and reference numeral 1c indicates an optical ground station operation management system for a North American organization. CM is a general term for the cloud occupation messages CM1 and CM2 of low-rise clouds and high-rise clouds, and NP indicates a network plan (operation plan). LPS (Laser Planning Systems) _A indicates the optical operation planning apparatus 30a, LPS_B indicates the optical operation planning apparatus 30b, and LPS_C indicates the optical operation planning apparatus 30c.

There are a number of optical operation planning devices 30 according to the institution to which the spacecraft (for example, spacecraft 5) belongs. If there is one organization, the number of optical operation planning devices 30 is one, and as shown in FIG. 12, if there are three organizations, there are three. Here, the optical operation planning apparatus of each organization is the optical operation planning apparatus 30a, the optical operation planning apparatus 30b, and the optical operation planning apparatus 30c.

In the optical ground station operation management system 1 according to the present embodiment, when the number of the optical operation planners 30 is one, the limited optical operation planners 30 are the master stations that judge and execute the network control. On the other hand, when there are three optical operation planning devices 30 as shown in FIG. 12, for example, one of the optical operation planning devices 30a, 30b, and 30c that can be switched according to the operation priority order of the spacecraft of the institution is mastered. Stations and others are defined as supporting devices. In either case, the master station has the authority to judge and control the station switching to improve the efficiency of the data downlink from the spacecraft that avoids clouds for the plurality of optical ground stations 2a, 2b, and 2c. be able to.

The optical operation planning device 30 of the master station (for example, the optical operation planning device 30a) controls the network switching between the optical ground stations based on the collected information and the network switching judgment criteria. This network switching judgment standard (“standard ratio” described later) can be changed depending on the relationship between the annual cloud occupancy rate of the locations where the optical ground stations 2a, 2b, 2c are installed and the communication time with the spacecraft. ing. Further, the network switching control is on condition that the switching processing is sufficiently in time with respect to the processing (prepass processing) time before the start of operation in each optical ground station 2a, 2b, 2c of each spacecraft.

FIG. 13 is a flowchart showing the operation of the optical operation planning device 30.
The optical operation planning device 30a of the master station takes in the orbit forecast value of the spacecraft 5 and creates an initial operation plan (step 1301). The orbit forecast value of the spacecraft 5 is fetched from a dedicated orbit analysis device via a communication network using orbit information provided by a predetermined site or a distance measurement service, for example.
Next, each optical operation planning apparatus 30 transfers the initial operation plan to each optical ground station 2a, 2b, 2c, sets it, receives a response to each setting, and confirms the setting completion (step 1302).
Next, each optical operation planning device 30 has a cloud occupancy message CM (cloud occupancy message CM1 of low-level clouds and high-rise clouds) as a result of the determination made by the low-rise cloud monitoring determination device 15 and a result determined by the high-rise cloud monitoring determination device 22. The capturing of the cloud occupancy message CM2) of the cloud is started (step 1303).

Next, the optical operation planning device 30a of the master station, based on the cloud occupation message CM,
Cloud occupancy rate at optical ground station 2a ≤ Reference rate [%]
Cloud occupancy rate at optical ground station 2b ≤ Reference rate [%]
Cloud occupancy rate at optical ground station 2c ≤ Reference rate [%]
It is determined whether or not (step 1304).
The optical operation planning device 30a of the master station maintains the initial operation plan when the cloud occupancy ratio in the optical ground station does not exceed the reference ratio (step 1305).
The reference ratio corresponds to a threshold value that serves as a reference for whether or not to execute the process of changing the initially designed optical operation plan (initial optical operation plan), and the optical operation planning apparatus 30a determines that the cloud occupancy rate is the same. When the standard ratio is exceeded, the changed optical operation plan is transferred to each optical ground station. The value of the reference ratio is not particularly limited, and can be arbitrarily set, for example, 50%, 60%, or 70% or more. Also, the reference ratio may be set to the same value or different values in each optical ground station.

On the other hand, if the cloud occupancy rate exceeds the reference rate, the optical operation planning device 30a of the master station calculates the cloud cover expected allocation time (BP) of the optical ground station that has exceeded the reference rate (step 1306). For example, when the cloud occupancy of the optical ground station 2a exceeds the reference ratio, the cloud shielding expected allocation time (BP: Blocking Plan) of the optical ground station 2a is calculated.
Next, the optical operation planning device 30a of the master station, in the optical ground stations 2b and 2c other than the optical ground station 2a,
t (change creation + transfer time) ≤ tb (pre-pass processing time of optical ground station 2b)
t (change creation + transfer time) ≤ tc (pre-pass processing time of optical ground station 2c)
It is determined whether or not (step 1307). That is, it is determined whether there is a changeable optical ground station from the optical ground station 2a. Here, the prepass processing time of the optical ground stations 2b and 2c is the time required for the preparation processing for station control.

The optical operation planning apparatus 30a of the master station, for example, when the optical ground station 2b is possible, creates a change plan for the optical ground station 2b and shares it with the optical operation planning apparatus 30b. The change plan is transferred to 2b, set, and a response is received (step 1308). When both the optical ground station 2b and the optical ground station 2c are available, the optical operation planning device 30a of the master station makes a plan to change to the optical ground station 2b or the optical ground station 2c of the next path on the time axis. The change plan is created and transferred to the optical ground station 2b or the optical ground station 2c via the optical operation planning device 30b or the optical operation planning device 30c for setting, and the response is received (step 1309).
The information of the operation plan transmitted from the optical operation planning apparatus 30a of the master station to the optical operation planning apparatuses 30b and 30c and the optical ground stations 2b and 2c is in the form of a message as shown in FIG.

FIG. 15 is a diagram illustrating a method of correcting an optical operation plan for avoiding cloud shielding. As shown in the figure, the optical ground stations 2a, 2b, and 2c are assigned operation plans in different time bands. In this embodiment, as shown in FIG. 1, the optical communication with the probe 5 is switched in the order of the optical ground station 2a, the optical ground station 2b, and the optical ground station 2c, and the data stored in the memory of the probe 5 ( For example, image data) is time-divisionally received by each ground station 2a to 2c.
The optical operation planning apparatus 30a of the master station makes an operation plan including an operation period (VP: Visible Plan) of the ground stations 2a to 2c. The VP includes an assigned time (AP: Assigned Plan) in which the ground stations 2a to 2c perform optical communication with the searcher 5, and pre-pass processing time and post-pass processing time set before and after that. When the optical operation planning device 30a determines that there is a period in which the cloud occupancy rate is equal to or higher than the reference rate within the AP period of one ground station, based on the cloud occupancy message CM, the cloud occupancy estimated allocation time ( BP: Blocking Plan) and modify the operation plan so that other optical ground stations can receive the data that was scheduled to be received during the BP period instead. In this case, the reassigned time RP (Reassigned Plan) for receiving the data scheduled to be received within the BP period of the one ground station is set in the AP of the other ground station. The "time required for changing the initial plan" shown in FIG. 15 is the time from the start time of the BP of the optical ground station 2a to the start time of the RP of the optical ground station 2b.

Next, a specific operation of the optical ground station operation management system 1 according to the present embodiment will be described with reference to FIGS. 16 to 19.

FIG. 16 shows an example of an allocation plan state of each optical ground station 2a, 2b, 2c in each optical operation planning apparatus 30a, 30b, 30c according to step 1304 and step 1306 of FIG. FIG. 17 shows the state of each optical ground station 2a, 2b, 2c.
As shown in FIG. 17, each of the optical ground stations 2a to 2c in each of the optical operation planning devices 30a to 30c has past cloud occupancy information (cloud occupancy rate changes with time), current cloud occupancy information (current cloud occupancy rate). ) Etc. In addition, these provide a cumulative service result that displays the amount of data received from the spacecraft 5 up to the present and the target amount of data, and the accumulated data of the amount of data received for each pass operation in the form of numerical values or an appropriate graph. Have a function.
The cumulative service result is the result of the data transmission service implementation by the optical communication link to each spacecraft that each optical ground station actually performed by the network switching control that realizes cloud avoidance, for example, the entire space-ground optical communication network. It is also used as an adjustment index for the setting change for the evaluation of the operation service utilization rate, and the switching determination process of the section information and the like described above for improving the service utilization rate. Here, as shown in the graph on the right side of the figure, the cumulative value of the received data amount at its own optical ground station and the received data amount at the other two optical ground stations are displayed for each path operation, and the cumulative value thereof is displayed. The effectiveness of the optical operation plan is evaluated by the change over time.

As shown in FIG. 17, the past cloud occupancy information (cloud occupancy rate) at the optical ground station 2a gradually increases, and the current cloud occupancy information (cloud occupancy rate) (at the time of determination in step 1304) is 70%. Has become. The past cloud occupancy information (cloud occupancy rate) at the optical ground station 2b is gradually decreasing, and the current cloud occupancy information (cloud occupancy rate) is 30%. The past cloud occupancy information (cloud occupancy rate) at the optical ground station 2c is gradually increasing, and the current cloud occupancy information (cloud occupancy rate) is 50%.

Assuming that the reference ratio in step 1304 is, for example, 70%, the optical ground station 2b or the optical ground station 2c is selected in step 1306. Then, for example, the optical ground station 2b is selected by the processing of step 1309. Therefore, as shown in FIG. 16, the data is cut off from the middle of the first path operation of the optical ground station 2a (corresponding to the BP period of FIG. 15), and the data is cut off from the beginning of the first path operation of the optical ground station 2b (of FIG. 15). Change to a plan to be inserted during the RP period).

FIG. 18 shows the exchange of data between the respective parts in the above step 1302 and step 1303. Further, FIG. 19 shows the exchange of data between the respective parts in step 1309 of FIG. 13, specifically, in the plan change shown in FIGS. 15 and 16. The optical ground station indicated by reference numerals 2a, 2b, and 2c in FIGS. 18 and 19 is composed of three blocks 201, 202, and 203. From the left, a block 201 is a main body of an optical ground station (control block) forming an optical ground station, a block 202 is a modem (transmission / reception device), and a block 203 is hardware such as a telescope for performing optical communication with a spacecraft.
Each optical ground station 2a, 2b, 2c performs pre-processing (pre-pass processing), path (AP), and post-processing based on the optical operation plan (plan 1, plan 2, plan 3) prepared by the optical operation plan device 30a. (Post-pass processing) is executed. Then, for example, when it is determined that the cloud occupancy ratio exceeds the reference ratio in the optical ground station 2a, a change (correction) in the optical operation plan for setting the BP period of the optical ground station 2a to the AP period of the optical ground station 2b is performed. It is executed (see FIG. 19).

As explained above, at present, a mechanism for avoiding clouds is not well established, and when using a laser in the atmosphere like optical communication between space and earth, conventional local dispersion technology alone If a cloud actually enters, the operation will be suspended. However, the optical ground station operation management system 1 according to the present embodiment determines cloud overlap with the target satellite orbit arc, and the optical operation planning device 30 performs cloud avoidance type optical ground station network control. The optical ground stations 2 (2a, 2b, 2c) with good conditions are efficiently selected between the spacecraft (for example, the spacecraft 5) and the optical ground station 2 without being obstructed by the intrusion of clouds. This can improve the efficiency of the data downlink. In addition, since data that could not be received by one optical ground station can be received by another optical ground station, it is possible to realize an optical operation plan by mutual complement (cross support) using multiple optical ground stations. it can.

It should be noted that the present invention is not limited to the above embodiment, and can be implemented with various modifications and applications. The scope of such implementation also belongs to the technical scope of the present invention.

For example, the mission that has a problem that operation is suspended due to cloud intrusion between the spacecraft and the ground station is not only for optical communication, but also for laser ranging and debris observation for objects that can be called a spacecraft in a broad sense, sunlight by laser. The present invention can also be applied to an optical ground system that optically operates through the earth's atmosphere, such as a power generation system.

Further, the cloud observed in the above embodiment is used for the control processing for the future time, but in the present invention, the cloud state message at the time of long-term switching (see FIGS. 6 and 10) is stored. By performing statistical processing based on this, the pattern of cloud entry at each ground station can be understood. Therefore, in controlling the switching timing and the like, the optical operation planning apparatus may be configured to perform an intelligent process of determining the switching timing based on the statistical data of the past cloud state tendency.

Note that, in the above embodiment, the image observed by the low-rise cloud monitoring / determining device 15 is an all-sky image in which the observation field of view through the fisheye lens is only the sky as shown in FIG. However, in the case where the image observed by the low-rise cloud monitoring / determining device 15 includes artificial structures such as surrounding buildings, mountains, rocks, trees, and other natural objects in addition to the sky, these artificial structures and natural objects are observed from the observation viewpoint. The low-rise cloud monitoring / determining device 15 is configured to further include a process for electronically removing the.

Furthermore, the problem of laser transmission in the atmosphere between the space and the ground is the influence of atmospheric fluctuations and the clouds that enter, but the aircraft 8 can see the increasing number of cases of laser emission from the ground these days. You must block the laser firing yourself when you enter inside. If the aircraft 8 enters the field of view for a long time, it will also cause a hindrance to communication between the spacecraft and the optical ground station. For this reason, the optical ground station has conventionally been provided with a security function as a mechanism for stopping the laser emission, but at present, there is no alternative but to stop the operation. On the other hand, according to the present invention, in this case, the optical ground station transmits a message to the optical operation planning apparatus 30 at a stage when a fixed time obtained from the stop of the operation time has elapsed, and the optical operation planning apparatus 30 By performing the switching control as in the cloud avoidance, it is possible to avoid the downlink service from being stopped for a certain period of time or more due to this problem, and improve the downlink efficiency.

[Other Embodiments]
Depending on weather conditions, fog may be generated around the optical ground station, and a certain area within the visual field of the fisheye lens in the low cloud monitoring and discrimination system or the entire visual field may be covered with fog. The fog scatters the rays of light, so it cuts off the communication like a cloud. Therefore, the present invention can make or modify the optical operation plan using the same method as the above-described embodiment for the purpose of avoiding not only the communication interruption due to the cloud but also the communication interruption due to the fog. is there.
On the other hand, the boundary between the fog and the area other than the fog is ambiguous, and it is difficult to specify the fog occupation area in the fisheye lens field of view.
Therefore, as an embodiment of the low-rise cloud monitoring / discrimination system 10 assuming the occurrence of fog at night, the brightness of the celestial body in the vicinity of the orbit of the satellite to communicate is measured from the image output of the visible camera 12. Brightness measuring means (not shown) may be further provided.

In this case, the low-level cloud monitoring / discrimination system 10 that also has a luminance measuring means measures the luminance of the celestial body using the luminance measuring means of the celestial body, and the luminance of the celestial body recorded in advance in a database (not shown). Compare with threshold. Here, the brightness threshold may be the minimum brightness of the celestial body in an atmospheric state in which ground-satellite communication is possible, or the brightness of the celestial body in fine weather at night. In this way, by comparing the brightness of the celestial bodies in the vicinity of the orbit of the satellite with the brightness threshold of the database, it is determined whether or not there is a meteorological phenomenon that may cause communication failure such as fog in the orbit of the satellite to be communicated. Output to the operation planning device 30.

The optical operation planning device 30 creates an optical operation plan for the satellite to be communicated, and then considers not only cloud occupancy data for the satellite orbit but also the presence or absence of a meteorological phenomenon such as fog. Can be modified. For example, even if the cloud occupancy ratio to the satellite orbit to be communicated is small, if the communication is determined to be impossible by the brightness measurement of the celestial body, the communication at the optical ground station is interrupted and another optical ground station is interrupted. Switch to.
Note that the above-mentioned celestial body has a luminance capable of measuring luminance and is not limited as long as it is a celestial body capable of predicting a trajectory. When the celestial body is a point light source such as a star, if the resolution of the optical system composed of the visible camera 12 and the fisheye lens is insufficient for luminance measurement, the second visible camera is tracked. Alternatively, the brightness measurement may be performed using a second visible camera.

In the above explanation, an example in which the fog is discriminated from the image captured by the visible camera has been described, but it is also possible to discriminate the fog from the image captured by the infrared camera. In this case, an image captured by an infrared camera in the low-level cloud monitoring and discrimination system on the ground may be used, an infrared image captured by a meteorological satellite may be used, or both of them may be used. For example, infrared images of meteorological satellites are processed by a method called Night microphysics RGB composition. Clouds can be seen by corresponding to 10.4 μm of infrared channel, but it is possible to distinguish fog by using other infrared channels before and after that and performing data subtraction and synthesis.

1: Optical ground station operation management system 2, 2a, 2b, 2c: Optical ground station 4, 4a, 4b, 4c: Meteorological satellite 8: Aircraft 15: Low level cloud monitoring / determining device 22: High level cloud monitoring / determining device 30, 30a, 30b, 30c: Optical operation planning device

Claims (13)

1. Taking in cloud image data in the field of view, drawing the expected orbit arc in the field of view of the spacecraft that connects the optical link with the optical ground station, the cloud image data in the field of view the expected orbit arc in the field of view A low-layer cloud monitoring and discriminating device that superimposes and discriminates the cloud occupancy ratio of the expected orbit arc in the field of view,
   Taking in cloud image data in a wide area, drawing an expected orbit arc of the spacecraft in the wide area, superimposing the wide area expected orbit arc on the wide area cloud image data to obtain a cloud occupancy ratio of the wide area expected orbit arc. A high-level cloud monitoring / discriminating device for discriminating,
   Based on the result determined by the low-layer cloud monitoring determination device and the result determined by the high-layer cloud monitoring determination device, to determine the cloud occupancy ratio of the low-rise cloud and high-rise cloud of the expected orbit arc of the spacecraft, An optical ground station operation management system, comprising: an optical operation planning device that manages an operation plan of the optical ground station based on the result of the discrimination.
2. The optical ground station management system according to claim 1,
   The low-rise cloud monitoring / determining device divides the predicted orbit arc in the field of view into two or more sections, determines the cloud occupancy rate of the predicted orbit arc for each section, and determines the cloud occupancy rate of the predicted orbit arc for each section. The total expected orbit arc cloud occupancy ratio of each of the sections is output to the optical operation planning device as a result of the determination by the low-level cloud monitoring determination device,
   The high-rise cloud monitoring / discriminating apparatus divides the predicted orbit arc of the wide area into two or more sections, judges the cloud occupancy rate of the predicted orbit arc for each section, and determines the cloud occupancy rate of the predicted orbit arc for each section and each. An optical ground station operation management system that outputs the cloud occupancy ratio of the total expected orbit arc of the section to the optical operation planning device as a result of the determination by the high-rise cloud monitoring and determination device.
3. The optical ground station operation management system according to claim 1 or 2,
   The high-rise cloud monitoring / discrimination device creates first arrival forecast information of a cloud that is close to the wide-area expected orbit arc to the expected orbit arc based on the wide-area cloud image data, and the first arrival forecast. Output information to the optical operation planning device,
   An optical ground station operation management system in which the optical operation planning device manages an operation plan of the optical ground station in consideration of the first arrival forecast information.
4. The optical ground station operation management system according to any one of claims 1 to 3,
   The low-level cloud monitor / discrimination device creates second arrival forecast information of a cloud close to an expected orbit arc in the field of view to the expected orbit arc based on the cloud image data in the field of view, and Output arrival forecast information to the optical operation planning device,
   The optical operation planning apparatus manages the operation plan of the optical ground station by also taking the second arrival forecast information into consideration.
5. The optical ground station operation management system according to any one of claims 1 to 4,
   The optical ground station operation management system, wherein the optical operation planning device accumulates any one of the cloud occupancy rates, and manages the operation plan of the optical ground station in consideration of the accumulated cloud occupancy rate.
6. The optical ground station operation management system according to any one of claims 1 to 5,
   The optical ground station further includes an operation stop message transmission unit that is provided in the optical ground station, acquires position information of the aircraft within the field of view of the optical ground station, and transmits an operation stop message to the optical operation planning apparatus based on the position information. ,
   The optical ground station operation management system, wherein the optical operation planning device manages the operation plan of the optical ground station in consideration of the operation stop message transmitted from the operation stop message transmission unit.
7. The optical ground station operation management system according to any one of claims 1 to 6,
   The low-level cloud monitoring discriminating device, the high-level cloud monitoring discriminating device and the optical operation planning device is installed for each of the plurality of optical ground stations arranged in different areas,
   The optical operation planning device, for each of the optical ground station, determines the cloud occupancy ratio of the low-rise clouds and high-rise clouds of the expected orbit arc of the spacecraft, and determines the overlapping state of the determined spacecraft orbit arc. An optical ground station operation management system that manages an operation plan for sequentially selecting and operating a station in good condition from a plurality of the optical ground stations based on the result.
8. The optical ground station operation management system according to claim 7,
   The optical operation planning device,
   Taking in the orbit forecast value of the spacecraft, creating an initial operation plan for sequentially operating the plurality of optical ground stations based on the orbit forecast value and transferring to each optical ground station,
   At least one of the plurality of optical ground stations executes a process of changing the initial operation plan when the cloud occupancy ratio of the low-rise clouds and the high-rise clouds of the expected orbit arc of the spacecraft exceeds a predetermined threshold value. An optical ground station operation management system that transfers the changed operation plan to each of the optical ground stations.
9. The optical ground station operation management system according to any one of claims 1 to 8,
   At least the exchange of data between the low-level cloud monitoring / discriminating apparatus and the optical operation planning apparatus and the exchange of data between the high-level cloud monitoring / determining apparatus and the optical operation planning apparatus are performed in the form of a message. Operation management system.
10. The optical ground station operation management system according to any one of claims 1 to 9,
    The spacecraft is an optical ground station operation management system for downlinking data to the optical ground station by optical communication.
11. Based on the cloud occupancy information from the low altitude cloud monitoring and discrimination device and the cloud occupancy information from the high altitude cloud monitoring and discriminating device, the cloud occupancy ratios of the low altitude clouds and the high altitude clouds to the predicted orbit arc of the spacecraft are determined, and the optical ground based on the results of the determination. An optical operation planning device equipped with a control unit that manages the operation plan of the station.
12. The cloud image data in the field of view near the optical ground station is taken in, and the expected orbit arc in the field of view of the spacecraft connecting the optical link with the optical ground station is drawn, and the cloud image data in the field of view is described above. Determine the cloud occupancy of the expected orbit arc in the field of view by superimposing the expected orbit arc in the field of view,
    Taking in cloud image data in a wide area, drawing an expected orbit arc of the spacecraft in the wide area, superimposing the wide area expected orbit arc on the wide area cloud image data to obtain a cloud occupancy ratio of the wide area expected orbit arc. Discriminate,
    Based on the determined cloud occupancy ratio of the predicted orbit arc in the field of view and the cloud occupancy ratio of the predicted orbit arc of the wide area, the cloud occupancy ratio of the low altitude cloud and the high altitude cloud of the predicted orbit arc of the spacecraft is determined. Then, the optical ground station operation management method for managing the operation plan of the optical ground station based on the determined result.
13. The cloud image data in the field of view near the optical ground station is taken in, and an expected orbit arc in the field of view of the spacecraft connecting the optical link with the optical ground station is drawn, and the cloud image data in the field of view is described above. Inputting the result of determining the cloud occupancy ratio of the expected orbit arc in the field of view by superimposing the expected orbit arc in the field of view,
    Taking in cloud image data in a wide area, drawing an expected orbit arc of the spacecraft in the wide area, superimposing the wide area expected orbit arc on the wide area cloud image data to obtain a cloud occupancy ratio of the wide area expected orbit arc. The step of inputting the determined result,
    Based on the input cloud occupancy ratio of the predicted orbital arc in the field of view and the cloud occupancy ratio of the predicted orbital arc of the wide area, the cloud occupancy ratio of the low altitude cloud and the high altitude cloud in the predicted orbital arc of the spacecraft is determined. Steps to
    A program for causing a computer to execute a step of managing an operation plan of the optical ground station based on a result of determining a cloud occupancy rate in which a low cloud and a high cloud of an expected orbit arc of the spacecraft are superimposed.

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