Galileo E5a/E5b and GPS L5 acquisition time statistical characterization and application to Civil Aviation
Résumé
The initial task of a receiver is to acquire at least four satellites and then track them to compute a first fix. The acquisition process is a two-dimensional search both in time and frequency. Indeed neither the received code delay nor the carrier Doppler frequency are perfectly known and so must be searched. In the literature, only the mean acquisition time and its standard deviation can be found for acquisition strategies such as the classical single dwell or double dwell serial time search processes. However this characterization is not sufficient for applications such as civil aviation for which time to first fix requirements are paramount. Given RTCA MOPS 229, the acquisition process performance may be stated in terms of probability of success so statistical characterization of the acquisition time such as the probability density function (Pdf) or, equivalently, the cumulative density function (Cdf) are required. The effect of key parameters such as the signal quality, the dwell time or the number of available correlators on the acquisition performance has been assessed.
Origine : Accord explicite pour ce dépôt
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