| 摘要 |
<p>A device for identifying aircraft on a runway has a plurality of sensors (20, 21, 22, 23, 24, 25, 26) spaced apart along a runway. A reference sensor (21) is adapted to be operated by the nosewheel of an aircraft and several of the other sensors (22, 23, 24, 25, 26) is spaced apart from the reference sensor (21) at distances corresponding to known wheelbases of different aircraft. By detecting coincident signals from the reference sensor (21) and one of the other sensors (22, 23, 24, 25, 26) it is possible to determine the wheelbase of the aircraft and thereby to determine which type of aircraft is travelling along the runway. By having a further sensor (20) situated before the other sensors, then by timing the interval between a signal from the further sensor (20) and the reference sensor (21), it is possible to obtain a value for the average speed of the aircraft along the runway.</p> |
