Phase correlation measurement
When measuring phase correlation, the emitted
light beam is a continuous amplitude-modulated signal in the visible or infrared range. The distance between the sensor and the object is determined from the phase shift between the emitted and the received signal. Different frequencies are used in order to prevent ambiguities in the case of larger ranges. Generally, up to three frequencies are used which each cover different measuring ranges with their wavelengths. The distance measurement value is determined from the results of all three measurements.