System for direction determination

摘要

System for determining the position of radar transmitters where the system includes at least one information center with associated cells and means of communication between the information center and the cells with a restricted transfer rate utilising existing infrastructure in the country, such as for example a national telephone network and also mobile telephone networks and their base stations. Each cell includes at least one sensor in order to be able to detect radar signals. Leading edges of pulses in the radar signals are detected and time-marked after which they are sorted according to PRI (Pulse Repetition Interval). The time of arrival for the first pulse in a pulse train is calculated and data reduced by modulo calculation to a value that as a maximum is the propagation time difference for pulses between two cells in a pair of cells/sensors that are used together for calculating the bearing. Bearings calculated from at least two pairs of cells are correlated in the information center which thereafter calculates the position of the radar transmitter.