Interferometric distance measurement method

摘要

An interferometric distance measurement method which utilizes a sequence of at least two closely spaced optical wavelengths in order to achieve ambiguity resolution during the measurement procedure. In so doing, this method performs the equivalent of measuring distances at a relatively long wavelength by measuring the phase difference at two closely spaced optical wavelengths and computing the effective phase measurement at a wavelength which corresponds to the frequency difference between the two optical wavelengths measured.