Abstract: The invention refers to a secondary surveillance radar, referred to hereinafter as SSR, system (1) for air traffic control. The SSR-system (1) comprises a plurality of secondary radar stations (2) and is adapted for determining a location of an air traffic vehicle within the range of coverage of at least some of the secondary radar stations (2) by means of propagation time measurement of data signals (8) transmitted between the secondary radar stations (2) and a transponder (9) of the air traffic vehicle. Each of the secondary radar stations (2) works on a synchronized local time base. In order to provide for a high-precision synchronisation of the radar stations (2) of the SSR system (1) free of clusters, it is suggested that an SSR system's (1) secondary radar station (2) is synchronized depending on the content of synchronisation signals (10) received by the secondary radar station (2) to be synchronized and broadcast by one of the other secondary radar stations (2) of the SSR system (1).

Abstract: The invention refers to a secondary surveillance radar, referred to hereinafter as SSR, system (1) for air traffic control. The SSR-system (1) comprises a plurality of secondary radar stations (2) and is adapted for determining a location of an air traffic vehicle within the range of coverage of at least some of the secondary radar stations (2) by means of propagation time measurement of data signals (8) transmitted between the secondary radar stations (2) and a transponder (9) of the air traffic vehicle. Each of the secondary radar stations (2) works on a synchronized local time base. In order to provide for a high-precision synchronisation of the radar stations (2) of the SSR system (1) free of clusters, it is suggested that an SSR system's (1) secondary radar station (2) is synchronized depending on the content of synchronisation signals (10) received by the secondary radar station (2) to be synchronized and broadcast by one of the other secondary radar stations (2) of the SSR system (1).