| 摘要 |
<p>The appts. comprises at least a data base (1) consisting of the signatures and positions of significant structures (22,23,24) around the airfield, a sensor (2) which detects the signatures of the structures and a navigation system (3) which accurately locates the position of the aircraft. A means of correlation compares the information from the data base with the known position of the aircraft and defines the bearings of the structures previously identified. The correlation allows the exact position of the aircraft to be determined as an aid to landing in all weather conditions. <IMAGE></p> |
