摘要 |
Described is a generalized approach for integer parameter estimation, especially in the context of Global Navigation Satellite Systems (GNSS). The problem solved is the case where a definitively correct integer solution cannot be identified for all ambiguity parameters in a reliable way. The proposed solution is to apply a linear transformation to the ambiguities (multiply with a matrix) such that the images of the first and the second candidate (or more) are identical. That way, from the first and second (and possibly more) candidates of the integer least-squares solution, a subset of ambiguity combinations is derived that can be fixed. Thus, it is no longer necessary to choose between the solutions as they coincide for the new ambiguities. The advantage of this approach is maximizing all information still available when finally deriving additional parameters such as position, clock error, atmospheric errors and/or time correlated noise. This technique is applicable to real-time and post-processing applications, as well as to pure GNSS applications, GNSS integrated with other sensors (e.g. INS) and other applications that have to resolve multiple integer ambiguities. This may also apply to optical distance-measurement. GNSS applications include kinematic and static positioning with single base stations as well as with multiple base stations or reference station networks. They also comprise the integer parameter estimation methods used within the reference station network computations.
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