PURPOSE: To enable the operator of a fixed station on the ground to easily judge a ship image even unless an information position matches a display position on a display unit by enabling an accurately position to easily be reported from a ship.

CONSTITUTION: On the ship, ship information radio equipments 110a and 110b are mounted which send information including the identification code of its station, and the position, speed, and course of the ship. The ground station has a radio equipment 117 which receives the ship information through an antenna, a ship video tracking means 121 which tracks the ship video outputted from a radar system 114 and stores the tracking data, a circular image display means 122 which finds the center position and radius of a circle on the display unit 115 on the basis of the tracking data and ship information and makes a display on the display unit 115 for a specific time, and a ship video display means 123 which displays the identification code corresponding to the ship video nearby the video image after the circle on the display unit 115 is erased while following up the corresponding ship video on the display unit 115 on the basis of the selected tracking data.