| 摘要 |
<p>A method is proposed for the optronic measurement of path lengths and angles. A first and a second optical beam (13, 14 or 61, 63) are directed, at given angles (a and b), at the surface (12) of the object to be measured so that both beams impinge on the surface at the same point, where diffraction will occur. In one embodiment of the invention, the two beams (13, 14 or 61, 63) have different frequencies. In another embodiment, the frequency of each beam is changed simultaneously and one of the beams is phase-modulated. The phase change in the output signal from the sensor (18) is determined by comparison with a reference signal.</p> |
