Systems and methods for GNSS ambiguity resolution

A method for Global Navigation Satellite System (GNSS) ambiguity resolution, the method comprising:

• receiving GNSS data from a plurality of GNSS receivers, wherein each of the GNSS receivers is coupled to a respective antenna;
• determining a standalone position of the plurality of GNSS receivers using pseudorange observations;
• performing error estimation using a double differenced code-based pseudorange;
• determining a covariance using the double differenced code-based pseudorange;
• selecting core satellites and defining a search space for ambiguity resolution by a first searching engine in its first epoch, wherein selecting core satellites is based on which satellites provide a best position-dilution-of-precision in the first epoch, wherein the search space for ambiguity resolution is larger than a code solution uncertainty;
• determining a first list of candidates for ambiguity resolution using the core satellites;
• adaptively setting residual thresholds based on measurement errors;
• eliminating candidates from the first list of candidates in response to a respective residual exceeding the adaptively set residual thresholds until a single candidate remains in the first list of candidates;
• determining position information using the single candidate remaining in the first list of candidates by applying ambiguities associated with the single candidate remaining in the first list of candidates;
• determining whether a second group of satellites different than the core satellites have a better position-dilution-of-precision than the core satellites in a first new epoch subsequent to the first epoch;
• in response to determining that the second group of satellites different than the core satellites have a better position-dilution-of-precision than the core satellites, the method further comprises:
• enabling a second searching engine using the second group of satellites, wherein the second searching engine is configured to operate in parallel with the first searching engine;
• determining a second list of candidates for ambiguity resolution using the second group of satellites;
• eliminating candidates from the second list of candidates in response to a respective residual exceeding the adaptively set residual thresholds until a single candidate remains in the second list of candidates;
• determining position information using the single candidate remaining from the second list of candidates by applying ambiguities associated with the single candidate remaining in the second list of candidates.

A non-transitory computer readable medium having computer-executable instructions stored thereon which, when executed by one or more processing devices, cause the one or more processing devices to:

• receive GNSS data from a first GNSS receiver communicatively coupled to a first GNSS antenna and a second GNSS receiver communicatively coupled to a second GNSS antenna;
• determine a standalone position of the first GNSS receiver and the second GNSS receiver using pseudorange observations;
• perform error estimation using a double differenced code-based pseudorange;
• determine a covariance using the double differenced code-based pseudorange;
• select core satellites that provide a best position-dilution-of-precision out of all visible GNSS satellites and define a search space for ambiguity resolution by a first searching engine in its first epoch, wherein the search space for ambiguity resolution is larger than a code solution uncertainty;
• determine a first list of three-dimensional (3D) position candidates for ambiguity resolution using the core satellites;
• adaptively set residual thresholds based on measurement errors;
• eliminate 3D position candidates from the first list of 3D position candidates in response to a respective residual exceeding the adaptively set residual thresholds until a single 3D position candidate remains in the first list of 3D position candidates;
• and
• determine 3D position information using the single 3D position candidate remaining in the first list of candidates by applying ambiguities associated with the single 3D position candidates remaining in the first list of candidates;
• wherein the computer-executable instructions, when executed by the one or more processing devices, cause the one or more processing devices to:
• determine whether a second group of satellites different than the core satellites have a better position-dilution-of-precision than the core satellites in a new epoch subsequent to the first epoch;
• in response to determining that the second group of satellites different than the core satellites have a better position-dilution-of-precision than the core satellites,
• enable a second searching engine using the second group of satellites, wherein the second searching engine is configured to operate in parallel with the first searching engine;
• determine a second list of 3D position candidates for ambiguity resolution using the second group of satellites;
• eliminate 3D position candidates from the second list of 3D position candidates in response to a respective residual exceeding the adaptively set residual thresholds until a single 3D position candidate remains in the second list of 3D position candidates;
• determine 3D position information using the single 3D position candidate remaining from the second list of 3D position candidates by applying the ambiguities associated with the single 3D position candidate remaining in the second list of candidates.