Adaptive multifrequency modulation method for an advanced laser range finder

The intensity of a laser beam is modulated with radio frequencies (RF), in a laser range finder. The modulated laser beam is directed to a target, and the reflected light is detected. The phase of the RP signal from the detector is measured. A semitransparent obstacle between the laser and the target degrades the accuracy of the range measurement. In this paper, an adaptive multifrequency modulation method is proposed and experimentally verified to overcome this problem.<
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