Orientation direction control device, optical communication terminal, optical communication system, and orientation direction control method

1. An orientation direction control device to control an orientation direction in which, in a satellite on which a first transmission/reception device to transmit and receive light and a second transmission/reception device to transmit and receive light or a radio wave are installed, the second transmission/reception device transmits and receives the light or the radio wave, the orientation direction control device comprising:

processing circuitry

to acquire orientation direction control information for controlling an orientation direction in which the first transmission/reception device transmits and receives the light, and

to control the orientation direction in which the second transmission/reception device transmits and receives the light or the radio wave, on a basis of the acquired orientation direction control information, wherein

the first transmission/reception device is a first optical communication terminal to perform optical communication with a first object via a first optical link,

the second transmission/reception device is a second optical communication terminal to perform optical communication with a second object via a second optical link,

the acquired orientation direction control information includes a first error defined as a difference between an orientation angle at which the first optical communication terminal performs optical communication with the first object via the first optical link and a target orientation angle, and

the processing circuitry calculates the first error, and

controls capture and tracking for maintaining the second optical link, by controlling an orientation direction in which the second optical communication terminal performs optical communication via the second optical link, on a basis of the acquired first error.

2. The orientation direction control device according to claim 1 , wherein the processing circuitry

estimates a second error of an orientation angle at which the second optical communication terminal performs optical communication via the second optical link, on the basis of the acquired first error, and controls the capture and tracking for maintaining the second optical link, by controlling the orientation direction in which the second optical communication terminal performs optical communication via the second optical link, on a basis of the second error estimated on the basis of the first error.

3. The orientation direction control device according to claim 2 , wherein the processing circuitry

acquires receiving direction information regarding a direction in which the second optical communication terminal receives light via the second optical link,

detects a third error of the orientation angle at which the second optical communication terminal performs optical communication via the second optical link by referring to the acquired receiving direction information, and

controls the capture and tracking for maintaining the second optical link, by controlling the orientation direction in which the second optical communication terminal performs optical communication via the second optical link, further on a basis of the detected third error.

4. An optical communication terminal as the second optical communication terminal, comprising:

the orientation direction control device according to claim 3 ,

a second optical communication terminal transceiver to detect the receiving direction information of the second optical communication terminal by receiving light via the second optical link, and

a second optical communication terminal capture and tracking mechanism to perform capture and tracking for maintaining the second optical link by changing an orientation direction of the second optical communication terminal transceiver on a basis of control by the processing circuitry.

5. An optical communication system comprising

an optical communication terminal as the second optical communication terminal according to claim 4 and the first optical communication terminal, wherein

the first optical communication terminal includes:

a first optical communication terminal transceiver to detect receiving direction information regarding a direction in which light is received via the first optical link, by receiving the light via the first optical link;

processing circuitry

to acquire the receiving direction information detected by the first optical communication terminal transceiver,

to detect the first error of the orientation angle at which the first optical communication terminal performs optical communication via the first optical link, by referring to the acquired receiving direction information, and

to control capture and tracking for maintaining the first optical link, by controlling an orientation direction in which the first optical communication terminal performs optical communication via the first optical link, on a basis of the detected first error; and

a first optical communication terminal capture and tracking mechanism to perform the capture and tracking for maintaining the first optical link, by changing an orientation direction of the first optical communication terminal transceiver, on a basis of control by the processing circuitry.

6. The optical communication system according to claim 5 , wherein

the processing circuitry

acquires a third error,

estimates a fourth error of an orientation angle at which the first optical communication terminal transceiver performs optical communication via the first optical link, on a basis of the acquired third error, and

controls the capture and tracking for maintaining the first optical link, by controlling an orientation direction in which the first optical communication terminal transceiver performs optical communication via the first optical link, further on a basis of the fourth error estimated on the basis of the third error.

7. The orientation direction control device according to claim 1 , wherein

the acquired orientation direction control information further includes a first orientation angle for control used for controlling an orientation direction in which the first optical communication terminal performs optical communication via the first optical link, and

the processing circuitry controls the capture and tracking for maintaining the second optical link, by controlling the orientation direction in which the second optical communication terminal performs optical communication via the second optical link, further on a basis of the acquired first orientation angle.

8. The orientation direction control device according to claim 7 , wherein the processing circuitry

converts the acquired first orientation angle to a second orientation angle for control used for controlling the orientation direction in which the second optical communication terminal performs optical communication via the second optical link, and

controls the capture and tracking for maintaining the second optical link, by controlling the orientation direction in which the second optical communication terminal performs optical communication via the second optical link, further on a basis of the second orientation angle converted on a basis of the first orientation angle.

9. An orientation direction control device to control an orientation direction in which, in a satellite on which a first transmission/reception device to transmit and receive light and a second transmission/reception device to transmit and receive light or a radio wave are installed, the second transmission/reception device transmits and receives the light or the radio wave, the orientation direction control device comprising:

processing circuitry

to acquire orientation direction control information for controlling an orientation direction in which the first transmission/reception device transmits and receives the light, and

to control the orientation direction in which the second transmission/reception device transmits and receives the light or the radio wave, on a basis of the acquired orientation direction control information, wherein

the first transmission/reception device is an optical communication terminal to perform optical communication with an object via an optical link,

the second transmission/reception device is an observation terminal to observe the Earth by transmitting and receiving light or a radio wave,

the acquired orientation direction control information is an error defined as a difference between an orientation angle at which the optical communication terminal performs optical communication with the object via the optical link and a target orientation angle, and

the processing circuitry calculates the error, and

controls an orientation direction in which the observation terminal transmits and receives the light or the radio wave on a basis of the acquired error.

10. An orientation direction control method for controlling an orientation direction in which, in a satellite on which a first transmission/reception device to transmit and receive light and a second transmission/reception device to transmit and receive light or a radio wave are installed, the second transmission/reception device transmits and receives the light or the radio wave, the orientation direction control method comprising:

acquiring orientation direction control information for controlling an orientation direction in which the first transmission/reception device transmits and receives the light; and

controlling the orientation direction in which the second transmission/reception device transmits and receives the light or the radio wave, on a basis of the acquired orientation direction control information, wherein

the first transmission/reception device is a first optical communication terminal to perform optical communication with a first object via a first optical link,

the second transmission/reception device is a second optical communication terminal to perform optical communication with a second object via a second optical link,

the acquired orientation direction control information includes a first error defined as a difference between an orientation angle at which the first optical communication terminal performs optical communication with the first object via the first optical link and a target orientation angle, and

the orientation direction control method further comprising:

calculating the first error, and

controlling capture and tracking for maintaining the second optical link, by controlling an orientation direction in which the second optical communication terminal performs optical communication via the second optical link, on a basis of the acquired first error.