News

1 Feb 2011

Impact of Pseudolite Signals on Non-Participating GPS Receivers

On the request of Galileo Infrastructure Unit (DG ENTR), IPSC/STA Unit carried out a technical study on Pseudo-satellites (pseudolites) and delivered a report entitled “Impact of Pseudolite Signals on Non-Participating GPS Receivers - Compatibility analysis for Commercial Receivers”. Preliminary results were obtained by the CORSA action on the impact of pseudolite signals on commercial non-participating GPS receivers. Scientists developed a methodology involving the collection of real GPS data and the addition of a synthetic pseudolite signal. The final results were data sets containing both real GPS L1 C/A signals and synthetic pseudolite components. From the analysis, it emerged that in the case of a continuous pseudolite modulation (the first case considered), the performance of the non-participating receiver is already significantly degraded when the pseudolite signal is about 10 times stronger than the average signal power. The use of a pulsing scheme significantly mitigates the impact of pseudolite signals and the receiver is able to maintain lock and provide a position solution for all the tested pseudolites. The JRC study identified need for further investigations to determine if higher pseudolite signal powers could affect more severely a non-participating receiver. JRC test results will be used by DG ENTR in developing technical specifications for a regulatory framework for safe and secure use of pseudolites in the EU for high precision navigation or geolocation services.