Patent ID: 6040898
Filing Date: 2000-03-21
Classification: G01S

Abstract:
A FMCW distance measurement method, comprising:modulating a wave train of carrier frequency f.sub.0 by a time function f(t) and splitting said wave train into a transmission signal and a reference signal in a deterministic phase relationship;putting the transmission signal onto a transmission link to be measured and feeding the reference signal to a phase difference-forming arrangement;feeding a signal reflected in the transmission link and delayed by the propagation time .tau. as a reception signal to the phase difference-forming arrangement;wherein the phase difference-forming arrangement forms the time difference function .theta.(t) of the phases between the reference and reception signals;evaluating the phase difference function .theta.(t) separately with respect to a direct component .theta..sub.= =g'(.tau., f.sub.0) assigned to the carrier frequency f.sub.0 and with respect to an alternating component .theta..sub.- (t)=g""(.tau., f.sub.- (t)) assigned to the modulation time function f(t); anddetermining the propagation time .tau. proportional to the distance by a combined evaluation of said direct component and said alternating component of the phase difference function.