Patent ID: 6753950
Filing Date: 2004-06-22
Classification: G01S

Abstract:
Optical distance measuring equipment comprisinga signal source for supplying a modulation signal, a transmission system connected to the signal source for transmitting a transmitted optical signal modulated by the modulation signal, a reception system for receiving a received optical signal which is a reflected and delayed version of the transmitted signal, and a cross-correlator arranged to carry out the steps of determining, at a coarse resolution, a time delay of the modulation signal needed to maximise the cross correlation between the time delayed modulation signal and the received signal, determining at a finer resolution than the coarse resolution, a time delay of the modulation signal needed to maximise the cross correlation between the modulation signal and the received signal as a function of the time delay of the modulation signal with respect to the received signal in a time delay range around the time delay determined at a coarse resolution, and outputting a measure of distance calculated from the time delay of the modulation signal determined at a finer resolution.