Arrangement for measuring the lag between two timed signals by electronic correlation

An arrangement for measuring the lag between two timed signals by electronic correlation, comprising:

• a first circuit for generating a numerical coded signal, means for transmitting the said coded signal through a transmission medium, means for receiving the coded signal after said transmission, a discriminator circuit of the type comprising two correlation circuits for correlating the coded signal received with respective ones of two reference coded signals reproducing said numerical code and relatively displaced in time in such a way that their respective auto-correlation functions partially overlap to form a common range of lag measurement, and a differential circuit for providing a signal representing the difference between the correlation outputs, a first synchronising circuit for synchronising with a first clock signal the said first generator circuit, a second generator circuit for producing the said two reference signals, a second synchronising circuit for synchronising the said second generator circuit using a synchronising signal whose frequency is locked to the amplitude of the said difference signal, and lag measuring means comprising two state-decoding circuits having inputs connected to the said generator circuits respectively and outputs connected to a measuring circuit, said state decoding circuits providing each a pulse signal, the time interval separating said pulse signals corresponding to the lag to be measured, the said first synchronising circuit providing a second clock signal for measurement purposes whose period is a sub-multiple of the period of said first clock signal to enable the said measuring circuit to count pulses.