Patent ID: 8928866
Filing Date: 2015-01-06
Classification: G01P,G01S

Abstract:
1. A velocity measuring device, comprising: an emitting device emitting an electromagnetic wave or an elastic wave toward a measurement object; an oscillating wavelength modulator causing the emitting device to operate so as to alternatingly be in a first emitting interval wherein the oscillating wavelength continuously increases monotonically and a second emitting interval wherein the oscillating wavelength continuously decreases monotonically; a detector detecting an electric signal that includes an interference waveform that is produced by the electromagnetic wave or elastic wave that is emitted from the emitting device and a reflected wave that is returned from the measurement object; a signal extractor calculating the number of interference waveforms included in the output signal of the detector during the first emitting interval and the second emitting interval; and a calculator calculating the velocity of measurement object based on a number of interference waveforms; wherein: the oscillating wavelength modulator causes the emitting device to operate so that the absolute values of the rates of change of the oscillating wavelengths in respect to time during the first emitting interval and the second emitting interval is different, wherein, if fmax is the maximum frequency of an interference waveform that is extracted by the signal extracting means, fmin is the minimum frequency of an interference waveform that is measured, T