About increase of accuracy of recirculation rangefinder based on a two-wavelength laser

For the account of the propagation speed of radiation, a precision laser rangefinders based on a two-frequency opto-electronic recirculation and the phase method of measurements have been developed. A semiconductor laser diode with asymmetric quantum-well heterostructure is used as the source of radiation at two different optical wavelengths. It allows to receive information on the propagation speed of laser radiation along the line of supervision and to take into account the exact value of the radiation speed in the distance calculations. Use of the dynamic threshold of comparator provides increase of measurement accuracy due to independence of influence of remote pulses amplitudes on result of measurements.