| 摘要 |
Methods and apparatus are provided for estimating parameters, i.e. ambiguities, derived from GNSS signals. Observations of GNSS signals are obtained from each of a plurality of GNSS satellites (1120). The observations are fed to a filter having a state vector at least comprising a float ambiguity for each received frequency of the GNSS signals (1140). The filter estimates a float value for each float ambiguity of the state vector. Integer values are assigned to at least a subgroup of the estimated float values to define a plurality of integer ambiguity candidate sets (1160). A quality measure is determined for each of the candidate sets. The best quality measure of the candidate sets is determined. An expectation value of the candidate set having the best quality measure is determined (1 170). An error measure as a ratio of the best quality measure to the expectation value is determined. The quality measures of the candidate sets is adapted as a function of the error measure (1180). A weighted average of a subgroup of the candidate sets on the basis of the adapted quality measures is formed, wherein at least one of selecting the subgroup of the candidate sets and the weighting of each candidate set in the weighted average is based on the adapted quality measure (1200). Ambiguities of the weighted average can be used in subsequent operations to aid in determining a position of the receiver or can be used to prepare data, e.g., in a network processor that can be used to augment position information of a rover. |
