US 12,407,412 B2
Optical communication system and flying object addressing system
Hisayuki Mukae, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 18/027,925
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Sep. 29, 2020, PCT No. PCT/JP2020/036804
§ 371(c)(1), (2) Date Mar. 23, 2023,
PCT Pub. No. WO2022/070237, PCT Pub. Date Apr. 7, 2022.
Prior Publication US 2023/0379054 A1, Nov. 23, 2023
Int. Cl. H04B 10/118 (2013.01)
CPC H04B 10/118 (2013.01) 22 Claims
OG exemplary drawing
 
1. An optical communication system configured of three communication satellites each including an optical communication device and an orbital attitude control device, and a ground facility, each optical communication device including a plurality of optical communication terminals, wherein
each of the plurality of optical communication terminals includes a biaxial rough-precision directivity control device and a biaxial high-precision directivity control device,
the orbital attitude control device includes a memory to record planned orbit information of the three communication satellites, and exchanges a control signal with the biaxial rough-precision directivity control device,
a first communication satellite flies as performing optical communication simultaneously with a second communication satellite and a third communication satellite,
the ground facility transmits, to the first communication satellite and the second communication satellite, a command of a time when optical communication starts,
the orbital attitude control device of the first communication satellite reads, from the memory, an orbit position of the second communication satellite at the communication start time, and transmits the control signal to the biaxial rough-precision directivity control device in one of the plurality of optical communication terminals of the optical communication device in the first communication satellite to cause the one of the plurality of optical communication terminals in the optical communication device of the first communication satellite to be directed to the second communication satellite,
the orbital attitude control device of the second communication satellite reads, from the memory, an orbit position of the first communication satellite at the communication start time, and transmits the control signal to the biaxial rough-precision directivity control device in one of the plurality of optical communication terminals of the optical communication device in the second communication satellite to cause the one of the plurality of optical communication terminals in the optical communication device of the second communication satellite to be directed to the first communication satellite,
from a state in which the first communication satellite and the second communication satellite are mutually directed to each other with rough precision, each establishes a high-precision directivity state by the biaxial high-precision directivity control device and, as mutually tracked by the biaxial rough-precision directivity control device in accordance with a relative position change based on the planned orbit information, each corrects a residual directivity error by the biaxial high-precision directivity control device,
furthermore, the ground facility transmits, to the first communication satellite and the third communication satellite, a command of a time when optical communication starts,
the orbital attitude control device of the first communication satellite reads, from the memory, an orbit position of the third communication satellite at the communication start time, and transmits the control signal to the biaxial rough-precision directivity control device in another one of the plurality of optical communication terminals of the optical communication device in the first communication satellite to cause the another one of the plurality of optical communication terminals in the optical communication device of the first communication satellite to be directed to the third communication satellite,
the orbital attitude control device of the third communication satellite reads, from the memory, an orbit position of the first communication satellite at the communication start time, and transmits the control signal to the biaxial rough-precision directivity control device in one of the plurality of optical communication terminals of the optical communication device in the third communication satellite to cause the one of the plurality of optical communication terminals in the optical communication device of the third communication satellite to be directed to the first communication satellite, and
from a state in which the first communication satellite and the third communication satellite are mutually directed to each other with rough precision, each establishes a high-precision directivity state by the biaxial high-precision directivity control device and, as mutually tracked by the biaxial rough-precision directivity control device in accordance with a relative position change based on the planned orbit information, each corrects a residual directivity error by the biaxial high-precision directivity control device.