PURPOSE: To enable tracking of a dot-like target having even a small S/N by emitting laser beams while rotating a frame, taking reflected beams into a pickup device through a gate, and applying serarch signal processing thereto.

CONSTITUTION: A frame driving signal is generated by a search frame signal generating unit 7 and thereby a pickup device 1 and a laser beam emitting unit 24 are moved. When detecting a target, a serarch signal processing unit 21 informs a target transfer decision circuit 22 on the detection, while computing the position of the target and driving a frame 10 so that the target is positioned in the center of the screen of the pickup device 1. Moreover, a laser timing unit 23 sends a laser beam emission instruction to a laser beam transmission-reception unit 24 synchronously with a vertical synchronizing signal of a television, while applying a gate to the pickup device 1 only for a prescribed period after emission of laser beams so as to set a limit to a distance whereat the target is taken as an image.