Distance measuring device, distance measuring method and distance measuring program

Case ID: 063

Web Published: 2/6/2021

A transmission unit (20) emits an electromagnetic wave having the same frequency f as an output signal from a sending unit (12) in a direction of a measurement axis (x-axis). A detecting unit (30) performs synchronous detection on a reflected wave (R) detected by a directional coupler (32) by an in-phase signal and a quadrature signal of the transmission signal, and by extracting DC component from the detection signal, detects the in-phase component (I(f)) and quadrature component (Q(f))of the reflected wave (R). An analysis signal generating unit (42) mixes the in-phase component (I(f)) and quadrature component (Q(f)) of the reflected wave (R) and signals (I0(f), Q0(f)), having periodicity corresponding to a prescribed distance (d0), and using only one of the resulting side bands, generates an analysis signal (p(f)).

Fourier transform unit (44) finds distance to the object of measurement from a profile (P(x)) obtained by Fourier transform of the analysis signal (p(f)).