PURPOSE: To implement a control relaying quickly and accurately from a searching radar to a PAR by performing a correlation processing of a searching radar target and a precision approach radar (PAR) target to display a control relaying state on both the radars.

CONSTITUTION: A target signal 501 detected from a radar video signal 401 processed in combination with flight plan information by a target processor 6 to be sent to a display device 7 as display signal 601 while aircraft information 602 of a target of a searching radar 20 recognized in a coverage of a PAR30 is outputted to a control relay information processor 2. On the other hand, a target signal 901 detected from a video signal 801 of the PAR 30 is processed with a target processor 10 to be sent to a display device 11 as display signal 1001 while a PAR aircraft information 1002 necessary for correlation processing is sent to the device 2. Then, the device 2 collates the information 602 with control relay aircraft information 101 and when an air craft to be relayed is identified, a further correlation processing is performed with the information 1002. When a correlation is found, a correlation target is sent out to the devices 6 and 10 to display 7 and 11 a control relay state of the target thereby accomplishing a relay for control quickly and accurately.