Uso Del segnale L2C nel posizionamento GNSS

The paper analyses the status of GPS modernization, and in particular the new L2C civil code and the advantages the introduction of this code could provide. For this purpose, an analysis of the six Block IIR-M satellites which currently transmit the L2C code was carried out, together with P2(y) paying particular attention to the quality of the transmitted signal and to the variations of one-way position accuracy. Some analysis of the SNR (Signal to Noise Ratio), on multipaths and on a Differential Code Bias of the new GPS code was carried out, comparing it with the old P2(Y) signal and the current C/A signal on the L1 band. A second analysis was carried out to realize a "one way" positioning (satellite-receiver) using the Kalman filter. The problem was set up in such a way as to estimate the phase ambiguity value on the L1 frequency and also on the L2 frequency, in order to evaluate the eventual improvements that the new L2C code could introduce in terms of time to fix (TTF) and noise of ambiguity.