Electronically steered inter-satellite optical communication system and methods

Patent metadata

Field	Value
Publication number	US-10243654-B1
Application number	US-201815941821-A
Country	US
Kind code	B1
Filing date	Mar 30, 2018
Priority date	Mar 30, 2018
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

Aspects are generally directed to an inter-satellite communication system and method of communicating between satellites. In one example, an inter-satellite communication system includes a first satellite transceiver having an entrance aperture, and a non-mechanical beamsteering device configured to steer a first beam of encoded optical data over a field of view thereof. The first satellite transceiver may include coarse steering optics configured to extend a field of regard of the non-mechanical beamsteering device. During a transmit mode, the coarse steering optics are positioned to transmit the first beam of encoded optical data through the entrance aperture in a direction of a second satellite transceiver. The first satellite transceiver may also include a beam splitter positioned, during a receive mode, to receive a second beam of encoded optical data from the second satellite transceiver and direct the second beam of encoded optical data to an optical sensor.

First claim

What is claimed is:

1. A method of communicating between satellites, the method comprising:
receiving ephemeris information at a first satellite transceiver, the ephemeris information specifying a first location of a second satellite transceiver;
providing a first beam of encoded optical data along a transmit path of the first satellite transceiver to a first beam splitter;
directing the first beam of encoded optical data to first coarse steering optics with the first beam splitter;
steering the first beam of encoded optical data over a field of view of a first non-mechanical beamsteering device of the first satellite transceiver;
transmitting, for a duration of a transmit mode of the first satellite transceiver, the first beam of encoded optical data through a first entrance aperture in a direction of the first location of the second satellite transceiver and over an extended field of regard of the first non-mechanical beamsteering device, the field of regard being extended relative to the field of view of the first non-mechanical beamsteering device by the first coarse steering optics;
switching a mode of operation of the first satellite transceiver from the transmit mode to a receive mode at an expiration of the duration of the transmit mode;
receiving a second beam of encoded optical data from the second satellite transceiver through the first entrance aperture during the receive mode, and directing the received second beam of encoded optical data along a receive path of the first satellite transceiver with the first beam splitter, wherein the receive path is distinct from the transmit path; and
focusing the second beam of encoded optical data on a first optical sensor of the first satellite transceiver with an optical focusing element positioned along the receive path.

2. The method of claim 1 , further comprising:
receiving at least the first beam of encoded optical data at the second satellite transceiver;
focusing the first beam of encoded optical data on a second optical sensor of the second satellite transceiver; and
estimating a trajectory of the first satellite transceiver based at least in part on the first beam of encoded optical data.

3. The method of claim 2 , further comprising transmitting the second beam of encoded optical data from the second satellite transceiver to a projected location of the first satellite transceiver based at least in part on the estimated trajectory of the first satellite transceiver.

4. The method of claim 3 , wherein transmitting the second beam of encoded optical data from the second satellite transceiver includes:
steering the second beam of encoded optical data over a field of view of a second non-mechanical beamsteering device; and
transmitting the second beam of encoded optical data to the projected location of the first satellite transceiver over an extended field of regard of the second non-mechanical beamsteering device, the field of regard being extended relative to the field of view of the second non-mechanical beamsteering device by second coarse steering optics.

5. The method of claim 1 , further comprising:
generating the first beam of encoded optical data, wherein the first beam of encoded optical data has a linear polarization; and
converting linear polarization to at least one of a left-handed circular-polarization and a right-handed circular polarization prior to transmitting the first beam of encoded optical data.

6. The method of claim 5 , wherein transmitting the first beam of encoded optical data over the extended field of regard of the first non-mechanical beamsteering device includes deflecting the first beam of encoded optical data at an angle based on a handedness of the circular-polarization.

7. The method of claim 1 , further comprising locating a second location of the second satellite transceiver prior to receiving the second beam of encoded optical data from the second satellite transceiver, the second location of the second satellite transceiver being different from the first location of the second satellite transceiver.

8. The method of claim 1 , wherein receiving the ephemeris information at the first satellite transceiver includes receiving the ephemeris information from a satellite ground station.

9. The method of claim 8 , further comprising locating the satellite ground station prior to receiving the ephemeris information from the satellite ground station.

10. The method of claim 1 , further comprising:
estimating a trajectory of the second satellite transceiver based at least in part on the second beam of encoded optical data; and
transmitting a third beam of encoded optical data from the first satellite transceiver to a projected location of the second satellite transceiver based at least in part on the estimated trajectory of the second satellite transceiver.

11. An inter-satellite communication system comprising:
a first satellite transceiver having a first entrance aperture and including:
a first non-mechanical beamsteering device configured to steer a first beam of encoded optical data over a field of view thereof;
first coarse steering optics configured to extend a field of regard of the first non-mechanical beamsteering device relative to the field of view of the first non-mechanical beamsteering device, wherein during a transmit mode of operation of the first satellite transceiver the first coarse steering optics are positioned to transmit the first beam of encoded optical data through the first entrance aperture in a direction of a location of a second satellite transceiver, and wherein the location of the second satellite transceiver is based on ephemeris information received at the first satellite transceiver;
a first beam splitter positioned, during the transmit mode of operation of the first satellite transceiver, to receive the first beam of encoded optical data along a transmit path of the first satellite transceiver and to direct the first beam of encoded optical data to the first coarse steering optics, and during a receive mode of operation of the first satellite transceiver, to receive a second beam of encoded optical data from the second satellite transceiver through the first entrance aperture and direct the second beam of encoded optical data along a receive path, the receive path being distinct from the transmit path;
first control circuitry configured to switch operation of the first satellite transceiver from the transmit mode to the receive mode at an expiration of a duration of the transmit mode;
a first optical sensor positioned along the receive path to collect the second beam of encoded optical data; and
an optical focusing element positioned in the receive path and configured to focus the second beam of encoded optical data onto the first optical sensor.

12. The inter-satellite communication system of claim 11 , further comprising an optical source configured to generate the first beam of encoded optical data, wherein the first beam of encoded optical data has a linear polarization.

13. The inter-satellite communication system of claim 12 , wherein the first control circuitry is operatively coupled to at least the optical source, the first non-mechanical beamsteering device, and the first coarse steering optics, the first control circuitry being configured to control the optical source, the first non-mechanical beamsteering device, and the first coarse steering optics to switch between the transmit mode and the receive mode of the first satellite transceiver.

14. The inter-satellite communication system of claim 13 , further comprising a quarter wave-plate interposed between the first non-mechanical be

Assignees

• Raytheon Co

Inventors

• Uyeno Gerald P
• Keller Sean D

Classifications

• H04B10/40

  Transceivers · CPC title

• H04B10/118 Primary

  specially adapted for satellite communication · CPC title

• H04B7/18521 Primary

  Systems of inter linked satellites, i.e. inter satellite service (for optical links between satellites H04B10/118) · CPC title