PURPOSE: To enable easy acquisition of a position of a moving target, a distance to the target from a pilot's own airplane, geographic information around the target, etc., by providing a pilot's own position detecting part, a map holding part, a map reading part, a moving object detecting device, an arithmetic part and a display part in the main.

CONSTITUTION: A pilot's own position detecting part 1 computes the latitude and the longitude of the position of a pilot's own airplane and sends them to a map reading part 3. The reading part 3 makes a map holding part 2 output of a map of some bounds on the basis of the latitude and the longitude, makes it be sent to a display control part 7 to be displayed 8, while sending rate of reduction of a scale of the map and the position of the pilot's own airplane to an arithmetic part 6. Meanwhile, a moving object detecting device 4 sends a distance L, an angle θ of application of a radio wave to a moving object and an azimuth angle to the arithmetic part 6. This part 6 computes data on the latitude and the longitude of a target on the basis of information on the altitude of the own plane inputted from an altimeter 5, the angle θ, the distance L and the azimuth from the device 4, the rate of the scale reduction of the map and information on the position of the own airplane from the detecting part 1 and converts them into data of a GPS display reduction scale. These data are sent to the control part 7 and this part 7 makes the moving object being the target be displayed 8 at a position specified by the arithmetic part 6 on the map sent from the holding part 2.