The geometry-free GPS ambiguity search space with a weighted ionosphere

Abstract.

In this contribution the impact of a presumed presence or absence of the ionospheric delays on the quality of the least-squares ambiguities is analysed. The spatial correlation and the time correlation of the ionospheric delays are captured in an a priori ionospheric variance matrix. 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 result an exact description can be given of the interpolatory character of the ambiguity variance matrix as function of the ionospheric weights. In order to give a qualitative analysis of the various effects, analytical rather than numerical results are emphasized.