| 摘要 |
<p>PROBLEM TO BE SOLVED: To carry out measurement of a distance with a less power of an emission signal by a method wherein a transmission signal is modulated by a PN pulse code signal to transmit a pules light and a comparison of the phase of the transmission signal is performed to measure a distance after a pulse compression processing of the received signal of reflected light. SOLUTION: Light which is modulated to (n) pieces of barker code system set at the repeated cycle the same as the oscillation cycle of a fundamental frequency emitting section 1 is transmitted from a light emitting section 4. The reflected light from a target is received by a photodetecting section 5 and a symbol is inpputed into a pulse compression part 7 through an AC coupler 15 and an amplifier 6. The compression section 7 performs a synchronous detection of a pulse code received and compresses the pulse width of the symbol to 1/n by a time series pulse code set to expand the pulse amplitude thereof by (n) times. A phase difference detecting section 13 detects a phase shift from outputs of LPFs 11 and 12. A signal processing section 14 calculates a distance to a target from a phase difference obtained.</p> |
