Patent ID: 8368900

Claim:
A lightwave interferometric distance measuring method, the method comprising: obtaining a plurality of distance measurement values by a lightwave interferometric measurement using simultaneously-output laser beams of plural wavelengths; accurately determining a determined geometric distance from a body of an interferometer to a target from the distance measurement values, while correcting a refractive index of air; and measuring the wavelengths of the laser beams by using a frequency-measuring system comprising an optical comb and one detector onto which the laser beams of plural wavelengths are simultaneously incident, wherein the obtaining the distance measurement values is to obtain the distance measurement values based on the laser beams oscillated from a plurality of lasers, wherein the measuring the wavelengths of the laser beams is to measure the wavelengths of the laser beams oscillated from the lasers by the optical comb, and wherein determining the determined geometric distance includes calculating a plurality of geometric distances by combinations of two of three or more distance measurement values, and determining the determined geometric distance in accordance with an average value of the calculated plurality of geometric distances.