Patent ID: 6614239
Filing Date: 2003-09-02
Classification: G01S

Abstract:
A process for measuring the distance of a moving body (12) from a fixed part (10), characterized in that it comprises the steps of:generating a first alternating signal (r(t)) having a frequency within the radio-wave range or the elastic-wave range; emitting the first signal from the fixed part towards the moving body (12); receiving the first signal (r(t)) on the moving body (12) and generating, on the moving body (12), a second signal (s(t)) having a frequency (nf) equal to the frequency of the first signal (r(t)) multiplied by a constant factor (n), the second signal (s(t)) having an initial phase (&phgr;1) equal to the phase (2&pgr;ft1+&phgr;0) at the instant (t1 ) in which it is received by the moving body (12); generating, on the fixed part, a third signal (u(t)) having a frequency (nf) equal to the frequency of the second signal (s(t)) and an initial phase (&phgr;0) equal to the initial phase of the first signal (r(t)); and determining the variation in distance of the moving body (12) in a pre-set time interval as a function of the variation in the amplitude of an alternating signal obtained from the sum of the second signal (s(t)) and the third signal (u(t)) in the same time interval.