Development of an optimization method for measuring the Doppler frequency of a packet taking into account the fluctuations of the initial phases of its radio pulses

Abstract

The necessity of estimating the decrease in the accuracy of measuring the informative parameters of a radar signal in real conditions of its propagation and reflection has been substantiated. The results of the estimation determine the requirements for optimizing this measurement to achieve the required efficiency. A numerical analysis of the decrease in the accuracy of measuring the Doppler frequency of a coherent packet is presented, depending on the statistical characteristics of fluctuations of the initial phases of its radio pulses. Expressions are given for calculating the fluctuation component of the measurement error of radio pulse packet frequency for various coefficients of interpulse correlation of phase fluctuations. An assessment is made of the possibility of increasing the accuracy of Doppler frequency measurement, which can be ensured by statistical optimization of the algorithm for time-frequency processing of a given radar signal by taking into account its phase fluctuations. The conditions for the multiplicative influence of phase fluctuations of radio pulses of the received packet are substantiated, which determine the efficiency of optimization of Doppler frequency measurement. Based on the results of the study, an optimization method for measuring the Doppler frequency of the packet taking into account fluctuations in the initial phases of its radio pulses is proposed. The accuracy of Doppler frequency measurement under the influence of both the internal noise of the radar receiver and the correlated phase fluctuations of its radio pulses is estimated. The efficiency of optimization of measuring the Doppler frequency of the packet is estimated taking into account fluctuations of the initial phases of its radio pulses by means of computer simulation. It is proved that, under the influence of phase fluctuations, the accuracy of Doppler frequency measurement can be increased due to the performed optimization from 1.86 to 6.29 times. This opens the way to improving the existing algorithms for measuring the higher time range derivatives to improve the quality of tracking complex maneuvering aerodynamic objects. This explains the importance and usefulness of the work for the radar theory.

Proposals to Improve the Information Capabilities of Coastal-Based Radar Stations for Surveillance of Surface and Air Objects

“…The optimal measurement of the Doppler frequency, accounting for the influence of correlated phase fluctuations in relation to a packet of unmodulated radio pulses, was considered in [11]. However, this type of radio signal does not provide high accuracy of range measurement, especially when radio waves propagate over the horizon.…”

Development of a method for estimating the effect of transformation of the normalized frequency mismatch function of a coherent bundle of radio pulses on the quality of radar frequency resolution

“…According to [16,21], the variance of the frequency measurement error of the bundle of radio pulses, which is due to the multiplicative effect of correlated phase fluctuations described by the oscillating correlation function, is determined by the expression:…”

“…in which the variance of the frequency measurement error of the bundle of radio pulses D is determined by expressions ( 19)- (21).…”

“…According to [6,[14][15][16]21], the influence of tropospheric inhomogeneities leads to phase fluctuations with a variance σ ϕ 2 0 01 10…”

“…-determine the variance of the frequency measurement error of the bundle of radio pulses due to the additive effect of the internal noise of the receiving device by expression (19); -determine the variance of the frequency measurement error of the bundle of radio pulses due to the multiplicative effect of the correlated phase fluctuations described by the oscillating correlation function by expression (20); -determine the total variance of the frequency measurement error of the bundle of radio pulses due to the effect of both these errors by expression (21); -estimate the frequency resolution in the presence of the additive effect of the internal noise and the multiplicative effect of correlated phase fluctuations by expression (23).…”