A PROPOSED GPS METHOD WITH MULTI-ANTENNAE AND SINGLE RECEIVER

A method based on multi-antennae linked to a common GPS receiver is pr oposed. The goal of the technique is to improve height determination f or baselines a few kilometres in length. The advantage of this techniq ue resides in the elimination of relative clock parameters in the ''be tween-antenna'' single difference observations. Because single differe nce observations are free of clock errors more geometrical strength re mains to determine the baseline components. This statement is valid as long as intercable biases can be carefully calibrated. For millimetre height determination, the intercable calibration must be done at the same level of accuracy. Under this assumption it is shown that in gene ral the height standard deviation improves by a factor of about three compared to standard GPS data processing. With the proposed method, th e effect of relative tropospheric zenith delay errors becomes a bit sm aller (in absolute value), compared to standard data processing. To ab sorb this error, a relative tropospheric zenith delay parameter may be estimated. Even with this additional parameter in the solution the he ight standard deviation remains two times smaller than the results of standard processing techniques (without tropospheric zenith delay para meter), and at least five times smaller than in the results obtained f rom standard processing including one tropospheric zenith delay parame ter.