Method, apparatus for carrier-phase cycle-slip detection and repair

1. A method of determining position, the method comprising:

observing a first signal from a first source at a first epoch;

observing a second signal from the first source at a second epoch;

observing a third signal from a second source at the first epoch;

observing a fourth signal from the second source at the second epoch;

generating a first set of comparison data based on the first signal and the second signal;

generating a second set of comparison data based on the third signal and the fourth signal;

determining whether cycle-slip exists based on the first set of comparison data and the second set of comparison data; and

determining a current position of a standalone global navigation satellite system (GNSS) receiver in response to a determination that cycle-slip does not exist,

wherein generating the first set of comparison data comprises resolving ambiguities using least-squares ambiguity decorrelation, and

wherein determining whether cycle-slip exists comprises determining that cycle-slip exists in response to a determination that the resolved ambiguity is non-zero.

2. The method of claim 1 , further comprising repairing the cycle-slip in response to a determination that cycle-slip does exist.

3. The method of claim 2 , further comprising determining the current position of the standalone GNSS receiver based on the repaired cycle-slip in response to the determination that cycle-slip does exist.

4. The method of claim 1 , wherein repairing cycle-slip with the non-zero ambiguity for observable that detected cycle-slip.

5. The method of claim 1 , wherein determining whether cycle-slip exists comprises determining that cycle-slip does not exist in response to a determination that the resolved ambiguity is zero.

6. The method of claim 1 , wherein observing the first signal comprises observing the first signal from a first satellite, and observing the third signal comprises observing the third signal from a second satellite.

7. The method of claim 6 , wherein the second satellite has a higher elevation than the first satellite.

8. A standalone global navigation satellite system (GNSS) comprising:

a non-transitory computer readable medium configured to store instructions thereon; and

a processor connected to the non-transitory computer readable medium, wherein the processor is configured to execute the instructions for:

observing a first signal from a first source at a first epoch;

observing a second signal from the first source at a second epoch;

observing a third signal from a second source at the first epoch;

observing a fourth signal from the second source at the second epoch;

generating a first set of comparison data based on the first signal and the second signal;

generating a second set of comparison data based on the third signal and the fourth signal;

determining whether cycle-slip exists based on the first set of comparison data and the second set of comparison data; and

determining a current position of a standalone global navigation satellite system (GNSS) receiver in response to a determination that cycle-slip does not exist,

wherein the processor is further configured to execute the instructions for generating the first set of comparison data by resolving ambiguities using least-squares ambiguity decorrelation, and

wherein the processor is further configured to execute the instructions for determining whether cycle-slip exists by determining that cycle-slip exists in response to a determination that the resolved ambiguity is non-zero.

9. The standalone GNSS of claim 8 , wherein the processor is further configured to execute the instructions for repairing the cycle-slip in response to a determination that cycle-slip does exist.

10. The standalone GNSS of claim 9 , wherein the processor is further configured to execute the instructions for determining the current position of the standalone GNSS receiver based on the repaired cycle-slip in response to the determination that cycle-slip does exist.

11. The standalone GNSS of claim 8 , wherein the processor is further configured to execute the instructions for determining whether cycle-slip exists by determining that cycle-slip does not exist in response to a determination that the resolved ambiguity is zero.

12. The standalone GNSS of claim 8 , wherein the processor is further configured to execute the instructions for observing the first signal from a first satellite, and observing the third signal from a second satellite.

13. A method of determining position, the method comprising:

observing a plurality of first signals from a first satellite;

observing a plurality of second signal from a reference satellite;

generating a first set of comparison data based on the plurality of first signals;

generating a second set of comparison data based on the plurality of second signals;

determining whether cycle-slip exists for the first satellite based on the first set of comparison data and the second set of comparison data;

determining a current position of a standalone global navigation satellite system (GNSS) receiver using the plurality of first signals in response to a determination that cycle-slip does not exist; and

repairing the cycle-slip of the first satellite in response to a determination that cycle-slip does exist,

wherein generating the first set of comparison data comprises resolving ambiguities using least-squares ambiguity decorrelation, and determining whether cycle-slip exists comprises determining that cycle-slip exists in response to a determination that the resolved ambiguity is non-zero.

14. The method of claim 13 , further comprising determining the current position of the standalone GNSS receiver based on the repaired cycle-slip in response to the determination that cycle-slip does exist.