PURPOSE: To obtain accurate target position data speedily by reading the contents of a memory by a processor when a target position is specified by marker setting on a display device which makes a two-dimensional display of a distance and an azimuth angle.

CONSTITUTION: A video signal from a receiver 4 is converted 6 into a digital signal, which is integrated 7 by range pins; and presence/absence information on the target by the range pins is obtained by a target detecting circuit 8. On the other hand, an azimuth-angle and an elevation-angle synchro signal of a bow reference deck surface polar coordinate system which are obtained by an azimuth board control circuit 10 are converted by S/D converting circuits 11a and 11b into digital signals. Further, an beam electron scanning angle in the elevation angle direction by a beam electron scanning control part 12 is added 13 to the signal from the circuit 11b to obtain the elevation angle of the beam synchronized with beam electron scanning. This beam elevation angle and the azimuth angle from the circuit 11a are converted 14 into a north reference horizontal polar coordinate system to become the directed position of a sent and received radio wave. The information from the circuit 8 is stored in a memory 9 according to the directed position of the sent and received radio wave and the distance and azimuth angle are displayed 5.