Relative Positioning in Europe:Influence of the GPS+Galileo Satellite Geometry

摘要

While the quality of the signals successfully transmitted byGIOVE A, the first Galileo satellite launched at the end of lastyear, is currently being checked, a lot of work still has to be donebefore Galileo will be fully operational. Our previous work,especially within the context of the pure geometric aspect, showedthat the use of the additional Galileo constellation with respectto GPS only, improves absolute positioning based on codeobservables with about 40% in terms of formal errors whensimulating urban conditions. For relative positioning based ondouble difference carrier phase observables, the concept of RDOP(Relative Dilution of Precision) allowed to demonstrate that usingGPS+Galileo, only half the observation time is sufficient to getsimilar precisions as with GPS only. These results were howeverobtained under error-free ideal conditions. The objective of thispaper is to extend previous research by taking now different errorsources into account, focusing only on results for relative position-ing. The components of the error budget will first be treatedseparately, and will be put together afterwards when investigatingthe global error.