Degradation in position accuracy in GPS/GLONASS system during meteor shower of 18 November 1998

It was anticipated that the performances of the global positioning system ( GPS) and GLONASS would have been affected during the entry of comet 55p (Te mple-Tuttle). The GPS/GLONASS signals were therefore monitored at a pre-sur veyed location of the National Physical Laboratory, New Delhi during this p eriod. A significant degradation in the positioning accuracy in the GPS/GLO NASS mixed mode was observed. The normal accuracy was found to have been re stored about 25h after the event. The reasons for these anomalies have not yet been ascertained.