| 摘要 |
A plurality of beams of electromagnetic energy having different known wavelengths in a vacuum are each operatively associated with an interferometer having a movable reflector to provide an output fringe pattern for each beam characterized by alternating annulment and reenforcement fringes. The reflector is moved causing movement of the fringes of each beam past an associated detector which provides an electrical output signal in response to alternating ones of the fringes as they move therepast whereby the electrical output signals represent a count of alternate fringes of each beam. The electrical output signals from the detectors are scaled and summed to provide a combination signal which represents the actual distance moved by the reflector and such distance has been inherently corrected for variations in ambient conditions. |
