| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a radar apparatus by which even a very small reflected signal from a target is detected surely, by which the distance to the target can be measured, and by which a relative speed is found without depending on the measurement of the distance. SOLUTION: On the basis of a sending-out timing signal from a trigger-pulse generation circuit 3, a laser head 10 sends out a frequency modulation signal at f1=f0+Δf with reference to a fundamental frequency f0 from a transmitting- receiving antenna. A received signal is converted into an IF signal at a difference frequencyΔf. A signal processing part 20 samples the IF signal so as to be integrated by a recording circuit. The amplitude change frequency of a sampled value is found by a Doppler detection circuit. A computing unit extracts a reflected signal from a sampled result, it finds a distance up to a reflecting target in the time of a receiving and transmitting operation, and it finds a relative speed on the basis of the amplitude change frequency. The time width of a transmitted signal contains one wave or higher of a reflected- signal waveform, and a sampling interval is set at 0.5/Δf or lower. As a result, the reflected-signal waveform is sampled in three points, and the reflected signal is detected surely.</p> |
