Electronic distance measuring method and electronic distance measuring instrument

摘要

An electronic distance measuring instrument comprises a pulsed light emitting light source, means for creating a distance measuring pulsed light and an internal reference pulsed light, a photodetector for detecting the pulsed lights, and a measuring unit for calculating a distance to an object to be measured based on a photodetection signal. The measuring unit performs coarse distance measurement based on difference of photodetection time between the internal reference pulsed light and the distance measuring pulsed light, carries out Fourier function transform on photodetection waveform of the pulsed lights respectively, separates the waveforms to a plurality of frequency components, obtains phase difference for each of the frequency components acquired, performs fine distance measurement based on time difference acquired from phase difference, and measures a distance to the object by adding a result of coarse distance measurement to a result of fine distance measurement.