| 摘要 |
<p>PURPOSE: To display both ground and an obstacle that protrudes from it on a display and make safe flight at a low altitude by tracking a plurality of targets simultaneously in time-sharing system. CONSTITUTION: A digital control module 22 generates a transmission pulse at a transmitter 29 and sets a time To applied to a transmission antenna 30 and the amplitude level of a transmission signal. At both sides of main return, transmission power level control is disabled and a full power is supplied, thus enabling to return from a target with a low reflection factor such as a treetop to be received. A return pulse is picked up by a reception antenna 34 and is inputted to an altitude meter including an amplification, band-limiting down conversion, and peak detection circuit 40 via a distance gate 36. Then, after A/D conversion, the output is applied to a threshold detector 42 and the presence or absence of the target is judged depending on whether the return signal exceeds a threshold or not. After the altitude of a plurality of targets that match a reference is registered in a RAM 24, it is displayed in multiple on a display device.</p> |
