THE INVERTIBLE GPS AMBIGUITY TRANSFORMATIONS

Certain linear combinations of the GPS-observables play a prominant ro le in the problem of ambiguity fixing. In particular ''wide-laning'' t echniques have proven to be very successful. At present, however, the various integer linear combinations that are considered, are restricte d to the single-channel dual-frequency case. In this contribution this class is generalized to the multi-channel case. First the two dimensi onal case is considered. It is shown how to infer which of the differe nt integer ambiguities can be paired. It turns out, for instance, that one is not allowed to pair the narrow-lane ambiguity to the wide-lane ambiguity. The two dimensional case is then generalized to higher dim ensions. And it is shown that admissible ambiguity transformations nee d to be integer and volume-preserving.