| 摘要 |
<p>Apparatus for the precise measurement of the displacement of a moving cooperative target from a reference position traveling, for example, over a distance of several meters, and with the measurement accuracy being better than fraction of a micrometer. The apparatus includes a low-cost laser which generates a beam of a selected frequency. The laser beam is directed at the moving target and is reflected by the target. The apparatus also includes additional elements which measure the Doppler phase shift of the reflected laser beam so as to obtain a precise measurement of the displacement of the target with respect to the reference position.</p> |
