Systems and methods for real time kinematic satellite positioning

Patent metadata

Field	Value
Publication number	US-2016116601-A1
Application number	US-201514621187-A
Country	US
Kind code	A1
Filing date	Feb 12, 2015
Priority date	Oct 27, 2014
Publication date	Apr 28, 2016
Grant date	—

Abstract

A method for Real Time Kinematic satellite positioning includes receiving navigation satellite carrier signals, receiving phase correction signals from a reference station, calculating a set of integer phase ambiguities from double-differenced measurements of pseudo-range and phase, and calculating a relative position of the mobile receiver from the set of integer phase ambiguities and the double-differenced measurements of pseudo-range and phase.

First claim

We claim:

1 . A method for Real Time Kinematic satellite positioning comprising:
at a mobile receiver, receiving a first navigation satellite carrier signal from a first navigation satellite, receiving a second navigation satellite carrier signal from a second navigation satellite, receiving a third navigation satellite carrier signal from a third navigation satellite, and receiving a fourth navigation satellite carrier signal from a fourth navigation satellite; at the mobile receiver, receiving first, second, third, and fourth phase correction signals from a reference station; at the mobile receiver, calculating a set of integer phase ambiguities from double-differenced measurements of pseudo-range and phase; and at the mobile receiver, calculating a relative position of the mobile receiver from the set of integer phase ambiguities and the double-differenced measurements of pseudo-range and phase.

2 . The method of claim 1 , wherein receiving a navigation satellite carrier signal comprises receiving a first GPS signal on an L1 frequency.

3 . The method of claim 2 , wherein receiving a navigation satellite carrier signal further comprises receiving a second GPS signal on an L2 frequency and combining the first and second GPS signals to create a beat signal.

4 . The method of claim 1 , further comprising receiving a set of additional phase correction signals from a second reference station; wherein calculating the relative position of the mobile receiver comprises calculating the relative position of the mobile receiver at least in part on the set of additional phase correction signals.

5 . The method of claim 1 , wherein receiving the first, second, third, and fourth phase correction signals comprises receiving the first, second, third, and fourth phase correction signals from a UHF radio.

6 . The method of claim 1 , wherein calculating a set of integer phase ambiguities comprises generating a first set of integer phase ambiguity hypotheses using a Kalman filter and performing hypothesis testing on the first set of integer phase ambiguity hypotheses.

7 . The method of claim 6 , wherein generating the first set of integer phase ambiguity hypotheses comprises generating the first set of integer phase ambiguity hypotheses using means and covariances generated by a Bierman-Thornton filter and at least one of a LAMBDA and an MLAMBDA algorithm.

8 . The method of claim 7 , wherein generating the first set of integer phase ambiguity hypotheses comprises generating the first set of integer phase ambiguity hypotheses from a measurement equation that relates phase change and pseudo-range to integer ambiguity without inclusion of a baseline vector; wherein generating the first set of integer phase ambiguity hypotheses comprises generating the first set of integer phase ambiguity hypotheses without a dynamic transition model.

9 . The method of claim 8 , wherein generating the first set of integer phase ambiguity hypotheses further comprises performing a decorrelating reparameterization of a hypothesis search space.

10 . The method of claim 9 , wherein performing hypothesis testing comprises performing hypothesis testing using a Bayesian update algorithm.

11 . The method of claim 10 , wherein performing hypothesis testing comprises performing hypothesis testing comprises removing a hypothesis from further testing based on a pseudo-likelihood of the hypothesis passing a threshold value.

12 . The method of claim 11 , wherein performing hypothesis testing comprises ceasing hypothesis testing when a ratio of probability of a most likely hypothesis to probability of a second-most likely hypothesis passes a threshold value.

13 . The method of claim 12 , further comprising generating a second set of integer phase ambiguity hypotheses after hypotheses from the first set of integer phase ambiguity hypotheses have been removed from further testing.

14 . The method of claim 13 , wherein generating the second set of integer phase ambiguity hypotheses comprises generating the second set of integer phase ambiguity hypotheses in response to a hypothesis search space becoming smaller than a threshold value.

15 . The method of claim 14 , wherein calculating the set of integer phase ambiguities comprises tracking relative probabilities in logarithmic space.

16 . A method for Real Time Kinematic satellite positioning comprising:
at a mobile receiver, receiving a first navigation satellite carrier signal from a first navigation satellite, receiving a second navigation satellite carrier signal from a second navigation satellite, receiving a third navigation satellite carrier signal from a third navigation satellite, and receiving a fourth navigation satellite carrier signal from a fourth navigation satellite; at the mobile receiver, transmitting carrier signal data corresponding to the first, second, and third navigation satellites from the mobile receiver to a remote computer; at the remote computer, receiving first, second, third, and fourth phase correction signals from a reference station; at the remote computer, calculating a set of integer phase ambiguities from double-differenced measurements of pseudo-range and phase; and at the remote computer, calculating a relative position of the mobile receiver from the set of integer phase ambiguities and the double-differenced measurements of pseudo-range and phase.

17 . The method of claim 16 , wherein calculating a set of integer phase ambiguities comprises:
generating a first set of integer phase ambiguity hypotheses using means and covariances generated by a Bierman-Thornton filter and at least one of a LAMBDA and an MLAMBDA algorithm; and performing hypothesis testing on the first set of integer phase ambiguity hypotheses.

18 . The method of claim 17 , wherein generating the first set of integer phase ambiguity hypotheses comprises generating the first set of integer phase ambiguity hypotheses from a measurement equation that relates phase change and pseudo-range to integer ambiguity without inclusion of a baseline vector; wherein generating the first set of integer phase ambiguity hypotheses comprises generating the first set of integer phase ambiguity hypotheses without a dynamic transition model.

19 . The method of claim 18 , wherein generating the first set of integer phase ambiguity hypotheses further comprises performing a decorrelating reparameterization of a hypothesis search space.

20 . The method of claim 19 , wherein performing hypothesis testing comprises performing hypothesis testing using a Bayesian update algorithm.

Assignees

• Swift Navigation Inc

Inventors

• Horn Ian Maxwell
• Noble Fergus Macpherson

Classifications

• G01S19/51

  Relative positioning · CPC title

• G01S19/44 Primary

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

• G01S19/32

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