System and method for determining GNSS corrections

Patent metadata

Field	Value
Publication number	US-12013468-B2
Application number	US-202318241542-A
Country	US
Kind code	B2
Filing date	Sep 1, 2023
Priority date	Sep 1, 2022
Publication date	Jun 18, 2024
Grant date	Jun 18, 2024

Abstract

A system can include (and/or receive data from) one or more data sources (e.g., satellites, reference stations, etc.), a computing system (e.g., a corrections generator thereof), a GNSS receiver, one or more sensors, and/or any suitable component(s). A method can include receiving satellite observations at a first signal frequency, determining GNSS corrections for a second signal frequency, determining a GNSS receiver position based on the GNSS corrections, and/or any suitable step(s).

First claim

We claim:

1. A system for correcting global navigation satellite systems (GNSS) signals comprising:
a processor configured to:
receive a first set of GNSS satellite observations from satellite signals tracked by GNSS receivers at a plurality of reference stations, wherein the satellite signals are transmitted with a first signal frequency, wherein the first set of GNSS satellite observations comprise code phase and carrier phase measurements associated with a plurality of satellites;
determine a satellite code bias and a satellite carrier phase bias associated with each satellite of the plurality of satellites based on the first set of GNSS satellite observations;
determine transformed satellite code bias and transformed satellite carrier phase bias by transforming the satellite code bias and the satellite carrier phase bias from the first signal frequency to a second signal frequency that differs from the first signal frequency; wherein a deviation between the transformed satellite carrier phase bias and a measured satellite carrier phase bias at the second signal frequency is at most 0.1 cycles; and

a second processor, collocated with a GNSS receiver of a rover, configured to:
receive a second set of GNSS satellite signals transmitted at the second signal frequency; and
determine a positioning solution of the rover using a set of corrected GNSS satellite signals formed by correcting the second set of GNSS satellite signals using the transformed satellite code bias and the transformed satellite carrier phase bias.

2. The system of claim 1 , wherein the first signal frequency and the second signal frequency are within a common frequency band.

3. The system of claim 1 , wherein the first signal frequency comprises a carrier frequency of 1176.45 MHz or 1561.098 MHz and wherein the second signal frequency comprises a carrier frequency of 1207.14 MHz or 1575.42 MHz.

4. The system of claim 1 , wherein the positioning solution of the rover comprises a receiver clock state wherein the receiver clock state accounts for a common offset in the satellite carrier phase bias between satellites.

5. The system of claim 4 , wherein the positioning solution is determined using differenced satellite signals between satellite signals of the second set of GNSS satellite signals, wherein the differenced satellite signals remove the common offset in the satellite carrier phase bias between satellites.

6. The system of claim 1 , wherein when the deviation exceeds 0.1 cycles for a satellite, measurements from the satellite are excluded from the set of corrected satellite signals.

7. The system of claim 1 , wherein determining the transformed satellite code bias and the transformed satellite carrier phase bias excludes an atmospheric delay contribution to the transformed satellite code bias and the transformed satellite carrier phase bias.

8. The system of claim 1 , wherein the transformed satellite carrier phase bias is determined according to

b

Φ

v
⁢
2

=

b

Φ

v
⁢
1

+

f
2

-

f
1

c

⁢

b

P

v
⁢
1

,

where b Φ v1 is the satellite carrier phase bias at the first signal frequency, b Φ v2 is the transformed satellite carrier phase bias, f 2 is second signal frequency, f 1 is the first signal frequency, c is the speed of light, and b P v1 , is the satellite code phase bias; and
wherein the transformed satellite code phase bias is determined according to: b P v2 =b P v1 , wherein b P v2 is the transformed satellite code phase bias.

9. The system of claim 1 , wherein determining the positioning solution of the rover comprises:
determining a set of carrier phase ambiguity hypothesis hypotheses for each satellite signal of the second set of GNSS satellite signals; and
selecting a carrier phase ambiguity of the set of carrier phase ambiguity hypotheses based on results of a hypothesis test comparing carrier phase ambiguities of the set of carrier phase ambiguity hypotheses;

wherein the positioning solution is determined using the carrier phase measurements of the second set of GNSS satellite signals based on the selected carrier phase ambiguities.

10. A method comprising:
receiving a set of GNSS satellite signals tracked by GNSS receivers at a plurality of reference stations, wherein the set of GNSS satellite signals are transmitted with a first signal frequency, wherein the first set of GNSS satellite signals comprise code phase and carrier phase measurements associated with a plurality of satellites;
determining a satellite code bias and a satellite carrier phase bias associated with each satellite of the plurality of satellites based on the first set of GNSS satellite signals; and
determining transformed satellite code bias and transformed satellite carrier phase bias by transforming the satellite code bias and the satellite carrier phase bias from the first signal frequency to a second signal frequency that differs from the first signal frequency; wherein the transformed satellite carrier phase bias is determined according to

b

Φ

v
⁢
2

=

b

Φ

v
⁢
1

+

f
2

-

f
1

c

⁢

b

P

v
⁢
1

Assignees

• Swift Navigation Inc

Inventors

• Smolyakov Ivan
• Carcanague Sébastien
• Angelo Joseph

Classifications

• G01S19/32

  Multimode operation in a single same satellite system, e.g. GPS L1/L2 · CPC title

• G01S19/44

  Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method · CPC title

• G01S19/072

  Ionosphere corrections · CPC title

• G01S19/43

  using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry · CPC title

• G01S19/071 Primary

  DGPS corrections · CPC title