Electronic vernier for laser range finder

摘要

An electronic vernier for a laser range finder enhances the resolution of the range finder to that of the vernier without increasing the frequency of the range clock. The range finder includes a range counter circuit for storing the total integer number of clock pulses produced by a range clock and counted by a range counter. The vernier includes a tapped delay line which subdivides the clock pulses into a predetermined plurality of equal increments. The contents of the tapped delay line at the time of transmission of the ranging pulse, and reception of the reflected ranging pulse identify the phase of the clock pulse. An electronic storage register of the vernier captures and stores the contents of the tapped delay line, and then transfers vernier transmission and reception fractions to a system controller for computing a corrected range measurement from the total integer number of clock pulses produced by the range clock and counted by the range counter. The error in the range measurement is reduced to the error range of the taped delay line without increasing the frequency of the range clock.