Un análisis de la presencia de nuevas frecuencias en las observaciones GNSS

Abstract

The modernization ofthe Global Positioning System (GPS) and the advent ofthe European Project Galileo willlead to a multifrequency Global Navigation Satellite System (GNSS). Single GNSS receiver observations could be used to estimate smoothed pseudoranges which, in turn, can be exploited to better estimate the absolute position ofthe receiver and its clock correction. In fact, if we consider the satellite ephemerides and satellite clock corrections as perfect quantities (i. e. not aJJected by errors). the adjustment of GNSS observations is broken down into two parts. In addition, the least squares (LS) theory leads to a feasible adjustment in two steps, where covariance matrices can be explicitty written, studied and propagated from one step to the other, so that a rigorous solution is finalIy obtained. In this papa the eJJect of the presence of a third GNSS frequency in the Precise Point Positioning (PPP) context is analyzed. Numerical tests with Galileo simulated data have been carried out.