| 摘要 |
PROBLEM TO BE SOLVED: To provide a measuring distance method using ultrasonic wave and measuring distance equipment which can cope with simultaneous measuring distance using many systems, without enlarging and complicating a system. SOLUTION: Ultrasonic pluses radiated into air are formed by modulating binary code by binary frequency shift keying system. The binary code is allocated and used from set of binary code wherein a peak value of cross correlation function and a maximum value of a side lobe of autocorrelation are small. Radiation of the ultrasonic wave pulses are performed by a resonance type transmitter, and computation of correlation is performed by a polar correlation method. COPYRIGHT: (C)2004,JPO
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