Patent ID: 8643827
Filing Date: 2014-02-04
Classification: G01S

Abstract:
1. Method for measuring light propagation time comprising the steps of: transmitting a first light signal, clocked by a first clock control with a first clock and a first clock signal, from at least one light transmitter into a light path by means of a reflecting object on to a photodiode, determining a received signal as a result of the first light signal at the photodiode, radiating a further light signal, clocked by a further clock control with a further clock and a further clock signal, from a further light transmitter directly to the photodiode at an angle to the first light signal and mixing said further light signal transmitted directly to the photodiode with the first light signal within the photodiode to produce a common received signal, filtering the common received signal using a filter, the frequency response of which corresponds to a frequency of a clock difference between the first clock and the further clock, to produce a filter signal, using the common received signal from the light path to determine a propagation time, mixing the first clock signal of the first clock control and the further clock signal of the further clock control to produce a mixed signal in a mixer, and using the phase shift between the mixed signal and the filter signal to determine the propagation time of light.