Interferometry-based satellite location accuracy

Patent metadata

Field	Value
Publication number	US-11638153-B2
Application number	US-202117186698-A
Country	US
Kind code	B2
Filing date	Feb 26, 2021
Priority date	Apr 1, 2020
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

According to one or more embodiments herein, interferometry-based satellite location accuracy is provided. In one embodiment, a method comprises: determining, generally at a substantially given time, a reference satellite having a known accurate location within angular proximity of a communication satellite having a known general location; determining an accurate angular position of the communication satellite with relation to the reference satellite from the perspective of at least one ground station antenna of a known accurate location; determining an additional location reference measurement of the communication satellite; determining an accurate location of the communication satellite at the substantially given time based at least in part on the accurate angular position of the communication satellite with relation to the reference satellite from the perspective of the at least one ground station antenna and the additional location reference measurement of the communication satellite; and utilizing the accurate location of the communication satellite.

First claim

What is claimed is:

1. A method, comprising:
determining, by a processing device, a reference satellite that is within an angular proximity of a communication satellite from the perspective of at least one ground station antenna of a known accurate location, the communication satellite having a known general location at a given time, and the reference satellite having a known accurate location at substantially the given time;
determining, by the processing device, an accurate angular position of the communication satellite with relation to the reference satellite at substantially the given time from the perspective of the at least one ground station antenna;
determining, by the processing device, an additional location reference measurement of the communication satellite at substantially the given time;
determining, by the processing device, an accurate location of the communication satellite at substantially the given time based at least in part on the accurate angular position of the communication satellite with relation to the reference satellite from the perspective of the at least one ground station antenna and the additional location reference measurement of the communication satellite; and
utilizing, by the processing device, the accurate location of the communication satellite,
wherein determining the accurate angular position of the communication satellite with relation to the reference satellite from the perspective of the at least one ground station antenna comprises:
obtaining a first signal from the reference satellite received at both a first antenna of a first ground station of a known accurate location and at a second antenna of a second ground station of a known accurate location;
obtaining a second signal from the communication satellite received at both a third antenna of the first ground station and at a fourth antenna of the second ground station; and
processing receipts of the first signal and second signal at both the first ground station and the second ground station to determine the accurate angular position of the communication satellite with relation to the reference satellite.

2. The method as in claim 1 , wherein the additional location reference measurement of the communication satellite comprises an accurate distance between the communication satellite and a particular ground station antenna of a known accurate location.

3. The method as in claim 2 , wherein the accurate distance between the communication satellite and the particular ground station antenna is calculated based on an echo message communicated from the particular ground station antenna to the communication satellite and back to the particular ground station antenna.

4. The method as in claim 2 , wherein the accurate distance between the communication satellite and the particular ground station antenna is calculated based on a one-way relay message communicated from an initiating ground station antenna via the communication satellite to the particular ground station antenna.

5. The method as in claim 2 , wherein the particular ground station antenna is one of the at least one ground station antenna.

6. The method as in claim 5 , wherein the accurate distance between the communication satellite and the particular ground station antenna is calculated based on a signal received by the at least one ground station antenna for use in determining the accurate angular position of the communication satellite with relation to the reference satellite.

7. The method as in claim 1 , wherein processing receipts of the first signal and second signal at both the first ground station and the second ground station to determine the accurate angular position of the communication satellite with relation to the reference satellite from the perspective of the at least one ground station antenna comprises:
determining a first differential one-way ranging (DOR) measurement based in part on comparing timing of receipt of the first signal from the reference satellite at the first antenna and the second antenna;
determining a second DOR measurement based in part on comparing timing of receipt of the second signal from the communication satellite at the third antenna and the fourth antenna;
calculating a delta-DOR measurement based on differencing the first DOR measurement and second DOR measurement; and
determining the accurate angular position of the communication satellite with relation to the reference satellite from the perspective of the at least one ground station antenna based on the delta-DOR measurement.

8. The method as in claim 1 , wherein the first ground station and the second ground station are separated by a baseline having a fixed and known distance.

9. The method as in claim 1 , wherein the second signal received from the communication satellite is based on a message initially communicated from a particular ground station.

10. The method as in claim 9 , wherein the message is communicated from the particular ground station to the communication satellite and back to both the third antenna and the fourth antenna.

11. The method as in claim 9 , wherein the particular ground station is selected from a group consisting of: the first ground station; the second ground station; and a third ground station other than the first ground station and the second ground station.

12. The method as in claim 1 , wherein the at least one ground station antenna is selected from a group consisting of: the first antenna; the second antenna; the third antenna; and the fourth antenna.

13. The method as in claim 1 , further comprising:
compensating for movement of the reference satellite when processing the first signal received from the reference satellite.

14. The method as in claim 13 , wherein compensating comprises:
determining a relative speed of the reference satellite; and
shifting a frequency of the signals received from the reference satellite to compensate for Doppler shift based on the relative speed.

15. The method as in claim 1 , wherein the additional location reference measurement of the communication satellite comprises at least two additional accurate angular positions of the communication satellite with relation to one or more respective reference satellites at substantially the given time from the perspective of at least two additional respective ground station antennas of respective known accurate locations.

16. The method as in claim 15 , wherein at least one of the one or more respective reference satellites is the same as the reference satellite.

17. The method as in claim 1 , wherein the first ground station and second ground station are clock synchronized.

18. The method as in claim 1 , wherein the accurate angular position is based on angular estimation by the at least one ground station antenna.

19. The method as in claim 1 , wherein utilizing the accurate location of the communication satellite comprises determining a location of an object based at least in part on a determined distance between the object and the communication satellite.

20. The method as in claim 1 , wherein utilizing the accurate location of the communication satellite comprises reporting the accurate location to a remote processing device.

21. The method as in claim 20 , wherein the remote processing device is caused to determine a location of an object based at least in part on a determined distance between the object and the communication satellite.

22. The method as in claim 21 , wherein the remote processing

Assignees

• Higher Ground Llc

Inventors

• Reis Robert S
• Shaffer Shmuel
• Reis Darren Robert
• Behmke James M
• Reuss David Alexander

Classifications

• G01S19/20

  Integrity monitoring, fault detection or fault isolation of space segment · CPC title

• G01S19/215

  issues related to spoofing · CPC title

• G01S19/258

  relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view · CPC title

• G01S19/00

  Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems · CPC title

• G01S19/45

  by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement · CPC title