FIELD: physics.
SUBSTANCE: network element (M) for generating backup data has a control element (M.1) for generating back up data relating to one or more base stations (S1, S2) of at least one navigation system, and a transmitting element (M.3.1) for transmitting back up data over a communication network (P) to a device (R). The positioning device (R) has a positioning receiver (R3) for positioning based on one or more signals transmitted by base stations (S1, S2) over at least one of the said satellite navigation systems; a receiver (R.2.2) for receiving back up data relating to at least one navigation system from the network element (M); and an analysis element (R.1.1) adapted for analysing the received back up data in order to detect information relating to the status of the said one or more signals from the base stations (S1, S2) of the navigation system. The said information relating to the status of the said one or more signals from the base stations (S1, S2) contain indicators to the base station (S1, S2) to which the signal relates, and the said status, which indicates suitability of the signal for using. The device (R) is adapted such that, the signal indicated as unsuitable for use is not used for positioning.
EFFECT: increased accuracy of determining location by providing the positioning device with a list of defective signals transmitted by a specific satellite.
29 cl, 6 dwg, 5 tbl
