Means for alleviating a discontinuity in the coverage between adjacently located multilateration systems

摘要

An apparatus and method are provided to cater for the positioning of an aircraft 16 in a boundary zone 18 between two adjacent multilateration systems 1,2. A controller 14 in a first system 1 receives Time Difference of Arrival (TDOA) data provided by the controller 15 in the second system 2. The controller 15 derives the TDOA data from time of arrival data provided by its local receiver stations 9-13. The controller 14 uses the TDOA data and also time of arrival data from its local receiver stations 4-8 to perform a multilateration to determine the location of the aircraft 16. The data originating from different sets of receiver stations may be utilised without the need for the timings of the two systems 1,2 to be synchronised.