| 摘要 |
<p>PURPOSE:To prevent collision with a front ground shape at a low cost by equipping a forward transmitting and receiving antenna and a forward/downward transmitting and receiving antenna switcher, and using existing facilities at the same time. CONSTITUTION:A control signal is emitted from a timing controller 10, and switching motion is made while a transmission switcher 3, reception switcher 6, and demodulated signal switcher 9 are synchronized. Thereby the distance from an ahead situated ground object as an obstacle and the distance from a down situated ground object are measured on the time division basis by the use of forward antennas 4a, 5a and downward antennas 4b, 5b. The ahead distance and the altitude are subjected to tracking by respective calculation parts 11, 12, and the ahead distance output signal and altitude output signal obtained are displayed. The switching is conducted on the time division basis, for example in 2-3sec, and instructions about the ahead and down distances are given continuously using a hold circuit or a memory. When the altitude is as low as under 50 ft, the measurement of down distance is performed in priority so that the down distance is measured continuously. When the ahead distance is below a certain value, judgement is made by a means 15 and an alarm is given by an alarm 16.</p> |
