JP2012129610A - Optical space communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical space communication device that prevents observation data from disappearing and thus can increase transmission speed.SOLUTION: Based on weather information of an atmospheric state monitoring sensor 17 monitoring an atmospheric state between an observation satellite and a terrestrial station, the observation satellite 10, if there is no obstacle C, transmits observation data to the terrestrial station 20, and if there is an obstacle C, transmits the observation data to a stationary satellite 30, and at the time when an observation period ends, if there is no obstacle C, transmits notification indicating the temporarily stored observation data be returned to the stationary satellite 30, and transmits the observation data to the terrestrial station 20 when receiving the observation data from the observation satellite 30. The stationary satellite 30 temporarily stores the observation data from the observation satellite 10 in a communication data storage unit 31, and when receiving notification indicating the observation data be returned, transmits the temporarily stored observation data to the observation satellite 10.

Description

  The present invention relates to an optical space communication device for transmitting observation data from an observation satellite to a ground station using optical communication between the observation satellite and the ground station.

  A typical conventional space optical communication apparatus includes an observation satellite, a plurality of receiving stations installed at different points, and a central station that receives and processes data transmitted from the plurality of receiving stations. The central station has means for acquiring weather information between the satellites, and the central station is configured to alternatively designate and control a station serving as a communication station according to the weather information of the receiving station installation location notified from each ( For example, see Patent Document 1).

JP-A-10-65620

  Conventional optical space communication equipment for transmitting observation data from observation satellites to ground stations cannot transmit observation data from observation satellites to ground stations when switching ground stations according to weather information. There was a problem that data loss occurred.

  In addition, when it becomes impossible to reproduce the observation data due to the loss of the observation data, it is necessary to retransmit the observation data from the observation satellite to the ground station, and there is a problem that the recording medium of the observation satellite is enlarged.

  Furthermore, when the error of the observation data due to the loss reaches an undetectable range, there is a problem that the observation data having an error may be used as it is.

  The present invention has been made to solve the above-described problems. When transmitting observation data from an observation satellite to a ground station, it is possible to suppress the loss of the observation data, and to reduce the transmission speed. An object is to obtain an optical space communication device that can be improved.

  An optical space communication device according to the present invention includes an observation satellite that flies in a predetermined orbit over the earth and observes an observation region on the earth, a ground station installed at a predetermined position on the ground, and a stationary over the earth An optical space communication device comprising a geostationary satellite flying in orbit, wherein the observation satellite monitors an atmospheric condition between the observation satellite and the ground station and outputs weather information; and Based on weather information, when there is no shield between the observation satellite and the ground station, the first communication light is used to transmit observation data for a predetermined time to the ground station, and the observation satellite and the ground station When there is an obstacle between the ground stations, the second communication light is used to transmit observation data for a predetermined time to the geostationary satellite, and when the predetermined observation period ends, the weather information is Based on the shielding between the observation satellite and the ground station If there is not, the second communication light is used to send a notification that the observation data temporarily saved is returned to the geostationary satellite, and the temporarily saved observation data sent from the geostationary satellite When received, the first optical communication device overall control unit for transmitting the temporarily stored observation data to the ground station using the first communication light, and the geostationary satellite stores the communication data. When the communication data storage unit and the observation data transmitted from the observation satellite for a predetermined time are temporarily stored in the communication data storage unit and a notification that the observation data transmitted from the observation satellite is returned is received, And a second optical communication device overall control unit that transmits observation data temporarily stored in the communication data storage unit to the observation satellite using the communication light of No. 3.

  According to the optical space communication apparatus according to the present invention, it is possible to suppress the disappearance of the observation data, and to improve the transmission speed.

It is a figure which shows the whole structure of the space optical communication apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the observation satellite of the space optical communication apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the geostationary satellite of the space optical communication apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the operation | movement of the observation satellite of the space optical communication apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the state with a shield between an observation satellite and a ground station in the optical space communication apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the state which the shield which existed between the observation satellite and the ground station moved in the optical space communication apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the geostationary satellite of the space optical communication apparatus which concerns on Embodiment 1 of this invention.

  Hereinafter, preferred embodiments of an optical space communication device of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
An optical space communication apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 is a diagram showing an overall configuration of an optical space communication apparatus according to Embodiment 1 of the present invention. In the following, in each figure, the same reference numerals indicate the same or corresponding parts.

  In FIG. 1, an optical space communication device according to Embodiment 1 of the present invention is installed in a predetermined position on the ground, and an observation satellite 10 that flies in a predetermined orbit over the earth and observes an observation region on the earth. A ground station 20 and a geostationary satellite 30 flying in a geostationary orbit over the earth are provided.

  The observation satellite 10 moves while acquiring the observation data of the observation region D, and transmits the observation data to the ground station 20 using the communication light LA between the satellite and the ground. At the same time, atmospheric information on the communication path with the ground station 20 is acquired using the atmospheric state monitoring sensor light LB, and the shielding object C such as a cloud is detected. Further, an optical inter-satellite communication path P is provided between the observation satellite 10 and the geostationary satellite 30 to maintain a state in which observation data can be transmitted and received.

  FIG. 2 is a block diagram showing the configuration of the observation satellite of the optical space communication apparatus according to Embodiment 1 of the present invention.

  In FIG. 2, an observation satellite 10 includes a communication data generation unit 11, an optical communication device overall control unit (first optical communication device overall control unit) 12, a communication path switching unit 13, and a first optical transponder (transmission / reception). ) 14A, second optical transponder (transmission) 14B, first acquisition and tracking mechanism 15A, second acquisition and tracking mechanism 15B, optical antenna (for satellite) 16A, and optical antenna (for ground) 16B and an atmospheric state monitoring sensor 17 are provided.

  The observation satellite 10 generates transmission observation data by a communication data generation unit 11 that encodes the observed data. Next, according to the weather information from the atmospheric condition monitoring sensor 17, the optical communication device overall control unit 12 selects the communication path of the geostationary satellite 30 or the ground station 20, and the communication path switching unit 13 selects the first optical transponder 14A. The second optical transponder 14B is switched. Observation data is converted into an optical signal by the first optical transponder 14A or the second optical transponder 14B, and the directivity direction of the light beam is controlled by the first acquisition tracking mechanism 15A or the second acquisition tracking mechanism 15B. Observation data is transmitted from the satellite optical antenna 16A or the ground optical antenna 16B.

  FIG. 3 is a diagram showing the configuration of the geostationary satellite of the space optical communication apparatus according to Embodiment 1 of the present invention.

  In FIG. 3, the geostationary satellite 30 includes a communication data storage unit 31, an optical communication device overall control unit (second optical communication device overall control unit) 32, an optical transponder (transmission / reception) 33, and a capture and tracking mechanism unit 34. An optical antenna (for satellite) 35, an RF transponder (transmission) 36, and an RF antenna 37 are provided.

  The geostationary satellite 30 operates differently depending on transmission and reception. In transmission, the observation data temporarily stored in the communication data storage unit 31 is encoded to generate transmission observation data. Next, the optical communication device overall control unit 32 confirms whether optical communication with the observation satellite 10 is possible. If it is determined that the optical communication is possible, the optical transponder 33 converts the observation data into an optical signal and captures it. The tracking mechanism unit 34 controls the direction of the light beam, and observation data is transmitted from the optical antenna 35.

  In reception, an optical signal transmitted from the observation satellite 10 is received by the optical antenna 35, and the light tracking error is corrected by the acquisition and tracking mechanism unit 34. Next, the optical signal is decoded by the optical transponder 33, passes through the optical communication device overall control unit 32, and is temporarily stored in the communication data storage unit 31.

  In another embodiment, in reception, an optical signal transmitted from the observation satellite 10 is received by the optical antenna 35, and the light tracking error is corrected by the acquisition and tracking mechanism unit 34. Next, the optical signal is decoded by the optical transponder 33, a part thereof is modulated again as an RF signal by the RF transponder 36, and an RF communication wave E of electromagnetic waves is transmitted from the RF antenna 37 to the ground station 20. Further, the remaining signals of the optical transponder 33 are temporarily stored in the communication data storage unit 31 through the optical communication device overall control unit 32.

  The ground station 20 includes an optical antenna (not shown) for receiving the satellite-ground communication light LA and an RF antenna (not shown) for receiving the RF communication wave E transmitted from the geostationary satellite 30. Are provided at least.

  Next, the operation of the space optical communication apparatus according to the first embodiment will be described with reference to the drawings.

  First, the operation of the observation satellite 10 will be described.

  FIG. 4 is a flowchart showing the operation of the observation satellite of the space optical communication apparatus according to Embodiment 1 of the present invention.

  In step 101-102 of FIG. 4, the observation satellite 10 is controlled between the observation satellite 10 and the ground station 20 and between the observation satellite 10 and the geostationary satellite 30 by the optical communication device overall controller 12 that controls the entire observation satellite 10. The first and second acquisition and tracking mechanisms 15A and 15B are independently operated to secure a communication path.

  Next, in step 103, the observation satellite 10 confirms the completion of acquisition and tracking between the observation satellite 10 and the ground station 20 and between the observation satellite 10 and the geostationary satellite 30 by the optical communication device overall control unit 12, and then the atmospheric state Weather information between the observation satellite 10 and the ground station 20 is acquired by the monitoring sensor 17.

  Next, in step 104, the observation satellite 10 determines the presence or absence of the shielding object C such as a cloud from the atmospheric information monitoring sensor 17 by the optical communication device overall control unit 12, and the shielding object C such as a cloud. If there is no object, the process proceeds to the next step 105, and if there is an obstacle C such as a cloud, the process proceeds to step 111.

  Next, in steps 105-106, the observation satellite 10 has previously determined that the communication path switching unit 13 based on the control of the optical communication device overall control unit 12 completes switching of the communication path to the ground station 20. The observation data for the time is transmitted to the ground station 20, and the completion of the data transmission is confirmed. If observation data to be transmitted from the observation satellite 10 to the ground station 20 remains, the process returns to step 103 again, and repeats steps 103-106. When the transmission of the observation data is completed, the communication of the observation satellite 10 is terminated.

  In steps 111-112, the observation satellite 10 notifies the geostationary satellite 30 to switch the communication path so that the observation data is transmitted to the geostationary satellite 30 by the optical communication equipment overall control unit 12, and the communication path is set to the satellite side. Switch to.

  Next, in steps 113 to 114, the observation satellite 10 transmits observation data for a predetermined time to the geostationary satellite 30 by the optical communication device overall control unit 12 and confirms the completion of the data transmission. Proceed to the next step 115.

  Next, in step 115, the observation satellite 10 confirms the completion of data transmission by the optical communication device overall control unit 12, and then obtains weather information between the observation satellite 10 and the ground station 20 again by the atmospheric state monitoring sensor 17. To do.

  Next, in step 116, the observation satellite 10 determines the presence or absence of the shielding object C such as a cloud by the optical communication device overall control unit 12 based on the weather information from the atmospheric state monitoring sensor 17, and the shielding object C such as a cloud. If there is no object, the process proceeds to the next step 117. If there is a cloud or other shielding object C, the process returns to step 113 and the processes of steps 113 to 116 are repeated again.

  Next, in steps 117 to 118, the observation satellite 10 stops transmission of observation data to the geostationary satellite 30 by the optical communication device overall control unit 12, switches the communication path to the ground station 20, and Notifies switching of communication path.

  Thereafter, in step 105, when the switching of the communication path to the ground station 20 is completed by the optical communication device overall control unit 12, the observation satellite 10 transmits observation data for a predetermined time to the ground station 20. To do. Thereafter, as described above.

  FIG. 5 is a diagram showing a state in which there is a shield between the observation satellite and the ground station in the space optical communication apparatus according to Embodiment 1 of the present invention.

  FIG. 5 shows a state in which the atmospheric state monitoring sensor light LB detects the shielding object C such as a cloud, and the communication light LA between the satellite and the ground is blocked by the shielding object C such as a cloud. In FIG. 5, when the communication light LA between the satellite and the ground is interrupted, the observation data is transmitted from the observation satellite 10 to the stationary satellite 30 by the optical inter-satellite communication light LC using the optical inter-satellite communication path P. .

  FIG. 6 is a diagram showing a state in which the shielding object between the observation satellite and the ground station has moved in the space optical communication apparatus according to Embodiment 1 of the present invention.

  FIG. 6 shows a state in which the shielding object C such as a cloud in FIG. 5 moves and the observation data is transmitted between the observation satellite 10 and the ground station 20 again using the satellite-ground communication light LA. Indicates.

  Next, the operation of the geostationary satellite 30 will be described.

  FIG. 7 is a flowchart showing the operation of the geostationary satellite of the space optical communication apparatus according to Embodiment 1 of the present invention.

  In step 301 of FIG. 7, the geostationary satellite 30 secures a communication path by operating the acquisition and tracking mechanism 34 between the observation satellite 10 and the geostationary satellite 30 by the optical communication device overall controller 32 that controls the entire geostationary satellite 30. To do.

  Next, in step 302, the geostationary satellite 30 confirms the completion of acquisition and tracking between the observation satellite 10 and the geostationary satellite 30 by the optical communication device overall control unit 32, and between the observation satellite 10 and the observation satellite 10 and the ground station 20 Get channel information based on weather information.

  Next, in step 303, the geostationary satellite 30 confirms whether or not the communication path is switched from the observation satellite 10 to the ground station 20 to the observation satellite 10 to the geostationary satellite 30 by the optical communication device overall control unit 32.

  Next, in Step 304, when the communication path is switched by the optical communication device overall control unit 32, the geostationary satellite 30 uses the communication path P to secure the observation data from the observation satellite 10 using the communication light LC. Receive.

  Next, in step 305, the geostationary satellite 30 temporarily stores the received observation data in the communication data storage unit 31 by the optical communication device overall control unit 32.

  As another embodiment, a part of the observation data for a predetermined time transmitted from the observation satellite 10 is obtained by using an RF communication wave E that is not affected by the shielding object C such as a cloud. It may be transmitted to the station 20.

  In step 306, the geostationary satellite 30 repeats the processing of steps 304 to 306 until the optical communication device overall control unit 32 notifies the observation satellite 10 of the completion of data transmission. When the data transmission is completed, the geostationary satellite 30 performs communication. finish.

  As shown in FIG. 6, when the observation satellite 10 ends the observation period of several minutes to several hours, the observation satellite 10 and the ground station 20 are shielded by a cloud C or the like, as shown in FIG. When there is no data, the communication light LC is used to transmit a notification to the effect that the observation data temporarily stored is returned to the geostationary satellite 30.

  When the geostationary satellite 30 receives a notification to return the observation data temporarily stored from the observation satellite 10, the geostationary satellite 30 transmits the observation data temporarily stored in the communication data storage unit 31 to the observation satellite 10 using the communication light LD. .

  When the observation satellite 10 receives the temporarily stored observation data transmitted from the geostationary satellite 30, the observation satellite 10 transmits the temporarily stored observation data to the ground station 20 using the communication light LA.

  As another embodiment, the observation satellite 10 is connected to the ground station 20 based on the weather information of the atmospheric state monitoring sensor 17 as shown in FIG. 5 when the observation period of several minutes to several hours is completed. When there is a shielding object C such as a cloud, a notification that the observation data temporarily stored to the geostationary satellite 30 is transmitted to the ground station 20 is transmitted using the communication light LC.

  When the geostationary satellite 30 receives a notification from the observation satellite 10 that the observation data temporarily stored is transmitted to the ground station 20, the observation data temporarily stored in the communication data storage unit 31 is transferred to the shielding object C such as a cloud. The observation data temporarily stored in the communication data storage unit 31 is transmitted to the ground station 20 using the RF communication wave E that is not affected.

  As described above, in the optical space communication apparatus according to Embodiment 1 of the present invention, when the observation data acquired by the observation satellite 10 is transmitted to the ground station 20, a shield such as a cloud is placed on the communication path between the satellite and the ground. When C exists, the channel is switched to the communication path P and the observation data is temporarily stored in the geostationary satellite 30. The state of the shielding object C such as a cloud is confirmed by the atmospheric state monitoring sensor light LB, and when it is determined that transmission via the satellite-ground communication path is possible again, transmission of observation data to the ground station 20 is resumed. In addition, by retransmitting the observation data temporarily stored in the geostationary satellite 30 to the observation satellite 10, it is possible to realize communication without loss of the observation data.

  DESCRIPTION OF SYMBOLS 10 Observation satellite, 11 Communication data generation part, 12 Optical communication apparatus whole control part, 13 Communication path switching part, 14A 1st optical transponder, 14B 2nd optical transponder, 15A 1st acquisition tracking mechanism part, 15B 2nd Capture and tracking mechanism section, 16A optical antenna, 16B optical antenna, 17 atmospheric condition monitoring sensor, 20 ground station, 30 geostationary satellite, 31 communication data storage section, 32 optical communication equipment overall control section, 33 optical transponder, 34 capture tracking mechanism Part, 35 optical antenna, 36 RF transponder, 37 RF antenna.

Claims (3)

An observation satellite that flies in a predetermined orbit over the earth and observes the observation area on the earth;
A ground station installed at a predetermined position on the ground;
An optical space communication device comprising a geostationary satellite flying in a geosynchronous orbit over the earth,
The observation satellite is
An atmospheric condition monitoring sensor for monitoring atmospheric conditions between the observation satellite and the ground station and outputting weather information;
Based on the weather information, when there is no shield between the observation satellite and the ground station, the first communication light is used to transmit observation data for a predetermined time to the ground station, When there is a shield between the ground stations, the second communication light is used to transmit observation data for a predetermined time to the geostationary satellite,
At the end of a predetermined observation period, based on the weather information, if there is no obstruction between the observation satellite and the ground station, the second communication light is used to temporarily When the notification of returning the stored observation data is transmitted and the temporarily stored observation data transmitted from the geostationary satellite is received, the temporarily stored observation data is transmitted to the ground using the first communication light. A first optical communication device overall control unit for transmitting to the station,
The geostationary satellite is
A communication data storage unit for storing communication data;
When the observation data transmitted from the observation satellite is temporarily stored in the communication data storage unit and a notification that the observation data transmitted from the observation satellite is returned is received, the third communication light is used. And a second optical communication equipment overall control unit for transmitting observation data temporarily stored in the communication data storage unit to the observation satellite. The second optical communication device overall controller is
The optical space communication apparatus according to claim 1, wherein a part of observation data for a predetermined time transmitted from the observation satellite is transmitted to the ground station using an RF communication wave. The first optical communication device overall controller is
At the end of a predetermined observation period, based on the weather information, if there is a shield between the observation satellite and the ground station, the second communication light is used to temporarily store the stationary satellite. Send a notification to send the stored observation data to the ground station,
The second optical communication device overall controller is
When receiving notification that the observation data transmitted from the observation satellite is to be transmitted to the ground station, the observation data temporarily stored in the communication data storage unit is transmitted to the ground station using the RF communication wave. The optical space communication apparatus according to claim 1 or 2, characterized in that:

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