System and method of free-space optical satellite communications

• US 20050100339A1
• Filed: 11/10/2003
• Published: 05/12/2005
• Est. Priority Date: 11/10/2003
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Tegge, Edward H. Jr.
• Granted Patent: US 7,593,641 B2
• Time in Patent Office: Days
• US Class Current: 398/125
• CPC Class Codes: H04B 10/118 specially adapted for satellite communication

Abstract

A system and method of free-space optical satellite communications includes a ground station and transceiver for transmitting and receiving an optical communications signal. Adaptive optics at the ground station are operative with the transceiver for determining the shape of any distortions in the wavefront of the optical communications signal and compensating at the ground station for the distortions. A satellite includes a transceiver for transmitting and receiving the optical communications signal and includes adaptive optics for determining the shape of any distortions in the waveform of the optical communications signal and compensating at the satellite for the distortions.

Claims

1. A system of free-space optical satellite communications comprising:

a ground station including a transceiver for transmitting and receiving an optical communications signal, including adaptive optics at the ground station and operative with the transceiver for determining the shape of any distortions in the wavefront of the optical communications signal and compensating at the ground station for the distortions; and

a satellite including a transceiver for transmitting and receiving the optical communications signal, including adaptive optics at the satellite for determining the shape of any distortions in the waveform of the optical communications signal and compensating at the satellite for the distortions.

2. A system according to claim 1 wherein each of said adaptive optics at the ground station and at the satellite comprises an adaptive mirror and a circuit operative with the adaptive mirror for deforming the adaptive mirror based on distortions determined in the wavefront of the optical communications signal.

3. A system according to claim 1 and further comprising a laser for generating a laser beam and creating an artificial point to aid in determining distortions within the wavefront of the optical communications signal.

4. A system according to claim 1 and further comprising a wavelength division multiplexer positioned at each of said ground station and satellite for wavelength division multiplexing the optical communications signal.

5. A system according to claim 4 wherein said multiplexer is operative for assigning incoming optical communications signals to specific frequencies within a designated frequency band.

6. A system according to claim 5 and further comprising a single mode optical fiber for receiving the multiplexed optical communications signals.

7. A system according to claim 4 and further comprising a demultiplexer positioned at each of said ground station and satellite for demultiplexing the wavelength division multiplexed optical communications signal.

8. A system according to claim 7 and further comprising a plurality of receivers operatively connected to said demultiplexer for receiving demultiplexed optical communications signals.

9. A system according to claim 1 wherein said transceiver within each of said ground station and satellite is operative of adjusting the transmission of the optical communications signal.

10. A system of free-space optical satellite communications comprising:

a ground station including a transmitter for transmitting an optical communications signal to a satellite; and

a satellite including a receiver for receiving the optical communications signal, including adaptive optics at the satellite for determining the shape of any distortions in the wavefront of the received optical communications signal and compensating at the satellite for the distortions.

11. A system according to claim 10 wherein said adaptive optics at the satellite comprises an adaptive mirror and a circuit operative for deforming the adaptive mirror based on distortions determined in the wavefront of the received optical communications signal.

12. A system according to claim 10 and further comprising a laser on the satellite for generating a laser beam and creating an artificial point to aid in determining distortions within the wavefront of the received optical communications signal.

13. A system according to claim 10 and further comprising a wavelength division multiplexer positioned at said ground station for wavelength division multiplexing the optical communications signal.

14. A system according to claim 13 wherein said multiplexer at the ground station is operative for assigning incoming optical communications signals to specific frequencies within a designated frequency band.

15. A system according to claim 13 and further comprising a single mode optical fiber at the satellite operative for receiving the multiplexed optical communications signals from the adaptive optics.

16. A system according to claim 13 and further comprising a demultiplexer within the satellite for demultiplexing the wavelength division multiplexed optical communications signal.

17. A system according to claim 16 and further comprising a plurality of receivers operatively connected to said demultiplexer for receiving demultiplexed optical communications signals.

18. A system according to claim 10 and further comprising adaptive optics at said ground station operative with the transmitter, wherein said adaptive optics is operative for adjusting the transmission of the optical communications signal.

19. A method of free-space optical satellite communications comprising the steps of:

transmitting and/or receiving an optical communications signal between a satellite and ground station;

determining the shape of any distortions in the wavefront of the optical communications signal; and

restoring a uniform wavefront to the optical communications signal using adaptive optics positioned at the satellite and/or the ground station.

20. A method according to claim 19 and further comprising the step of deforming optics within adaptive optics to restore a less distorted wavefront.

21. A method according to claim 19 and further comprising the step of receiving the optical communications signal on an adaptive mirror and deforming the adaptive mirror based on the distortions determined in the wavefront of the optical communications signal.

22. A method according to claim 19 and further comprising the step of generating a laser beam for creating an artificial point to aid in determining distortions within the wavefront of the optical communications signal.

23. A method according to claim 19 and further comprising the step of wavelength division multiplexing the optical communications signal.

24. A method according to claim 23 and further comprising the step of assigning incoming optical communications signals to specific frequencies within a designated frequency band.

25. A method according to claim 23 and further comprising the step of receiving the multiplexed incoming optical communication signals within a single mode optical fiber.

26. A method according to claim 23 and further comprising the step of demultiplexing the optical communications signal into a plurality of receivers.

27. A method according to claim 23 and further comprising the step of adjusting the transmission of the optical communications signal from the ground station to account for wavefront distortion as the optical communications signal passes through the atmosphere between the satellite and ground station.

28. A method of free-space optical satellite communications comprising the steps of:

transmitting an optical communications signal from a ground station to receiver optics positioned within the satellite;

determining the shape of any distortions in the wavefront of the optical communications signal received within the receiver optics; and

adjusting the receiver optics to restore a more uniform wavefront to the optical communications signal.

29. A method according to claim 28 and further comprising the step of deforming optics within adaptive optics to restore a less distorted wavefront.

30. A method according to claim 28 and further comprising the step of receiving the optical communications signal on an adaptive mirror and deforming the adaptive mirror based on the distortions determined in the wavefront of the optical communications signal.

31. A method according to claim 28 and further comprising the step of generating a laser beam for creating an artificial point to aid in determining distortions within the wavefront of the optical communications signal.

32. A method according to claim 28 and further comprising the step of wavelength division multiplexing the optical communications signal.

33. A method according to claim 32 and further comprising the step of assigning incoming optical signals to specific frequencies within a designated frequency band.

34. A method according to claim 32 and further comprising the step of receiving the incoming optical signals within a single mode optical fiber located in the satellite.

35. A method according to claim 32 and further comprising the step of demultiplexing the optical communications signal into a plurality of receivers within the satelite.

36. A method according to claim 28 and further comprising the step of adjusting the transmission of the optical communications signal from the ground station to account for wavefront distortion as the optical communications signal passes through the atmosphere between the satellite and ground station.