The method for improving of accuracy of correlation lag based on pre-filtering of input tracking circuit signals

The aim of the work is to substantiate a method for increasing the ac-curacy of the correlation lag based on preliminary filtering of the signals at the input of the tracking circuit. The problems solved with the help of correlation lags are shown. The analysis of the basic equations of the correlation methods for measuring velocity and structural schemes of computing devices of the correlation lags based on these methods is carried out. It is shown that when measuring the ship's longitudinal speed at the output of the tracking circuit (measured speed) of the correlator, even in the steady tracking mode, the signal is not equal to zero, in contrast to the correlation method for measuring the module of the ship's full speed. It is proposed to filter the signals at the inputs of the subtractor with the sub-sequent integration of the output difference signal. To confirm the operability of the proposed method, the longitudinal velocity meter and meter for the module of the full speed were simulated. The dynamic characteristics of the transients computing devices of the correlation lags, the dispersions of the input and output signals of the tracking circuits are obtained. The results of theoretical calculations of the relative mean square errors of the methods for measuring the longitudinal velocity and module of the full velocity are presented, as well as the results obtained during the simulation, which confirmed the effectiveness of the proposed method.