| 摘要 |
<p>PROBLEM TO BE SOLVED: To effectively detect the position of an aircraft even at the time of dense fog or severe snowfall and to eliminate the fault of service by providing a geomagnetic sensor embedded in the ground near the ground surface of a taxiway or apron as sensing means. SOLUTION: The lines of magnetic force of geomagnetism are parallel when there is no magnetic element, but are attracted to the element when there is the element such as an aircraft or a vehicle, and hence the magnetic flux density of the part is increased. Accordingly, when a geomagnetic sensor 51 is provided at a taxiway 2 to measure the magnetic field intensity near the ground surface, when an aircraft or the like is approached, the magnetic field is largely changed, and hence the presence of the aircraft can be detected. A position detector 52 detects the change of such distributed state according to the signal from the sensor 51, and submits the presence of the aircraft 1 when the change level exceeds a predetermined threshold value. IF the sensor 51 capable of measuring magnetic field changes of three axis directions is adopted, the position of the aircraft can be more accurately detected.</p> |
