A computer and a terminal apparatus retain position information about targets. The terminal apparatus includes: a capturing portion that captures an image of the target; a position information acquisition portion that acquires information about a position to capture the target; an orientation information acquisition portion that acquires information about an orientation to capture the target; and a communication portion that transmits the image, the position information, and the orientation information to the computer. The computer identifies at least one first target candidate as a candidate for the captured target from the targets based on the position information about the targets, the acquired position information, and the acquired orientation information. The computer identifies at least one second target candidate from at least the one first target candidate based on a distance from the terminal apparatus to the captured target.