Method and apparatus for measurement of short intervals by analysis of the propagation delay of a shaft

摘要

The distance between the target and the measuring means is segmented into adjacent distance compartments, the first begins to the zero distance. Each box distance at a level of energy associated obtained by the demodulation of the measurement signal of the delay resulting from the product of correlation between the emitted signal and the received signal reflected by the target. The process according to the invention is to create two distinct aliasing terms of the spectrum of the measurement signal of the delay, and the energy level corresponds to the first distance compartment, these folds being carried out on the part of the spectrum corresponding to the negative distances. These two aliasings distinct make it possible to obtain two separate energy levels (32, 33) on the whole of the first distance compartment and to measure thus, all the distances on this first distance compartment including the distances very low, or even almost zero by comparisons and analyses of the two energy levels (32, 33). br / application: measurement of short distances for detecting targets brought together.