THE GEOMETRY-FREE GPS AMBIGUITY SEARCH SPACE WITH A WEIGHTED IONOSPHERE

In this contribution the impact of a presumed presence or absence of t he ionospheric delays on the quality of the least-squares ambiguities is analysed. The spatial correlation and the time correlation of the i onospheric delays are captured in an a priori ionospheric variance mat rix. It is shown how the size and shape of the ambiguity search space is affected by the use of these a priori ionospheric weights. As a res ult an exact description can be given of the interpolatory character o f the ambiguity variance matrix as function of the ionospheric weights . In order to give a qualitative analysis of the various effects, anal ytical rather than numerical results are emphasized.