Device for measuring pulse repetition period

1975 ◽  
Vol 18 (3) ◽  
pp. 473-474
Author(s):  
I. S. Zholkina ◽  
V. I. Chernyshev
Keyword(s):  
Pulse Repetition ◽  
Repetition Period ◽  
Pulse Repetition Period

scholarly journals Suppression of correlated interference by adaptive notch filters under pulse repetition period modulation

2021 ◽  
pp. 53-60
Author(s):  
Sergey Ziatdinov ◽  
Leonid Osipov
Keyword(s):  
Noise Suppression ◽  
Pulse Repetition ◽  
Correlated Noise ◽  
Repetition Period ◽  
Notch Filters ◽  
Noise Spectral Density ◽  
Pulse Repetition Period ◽  
Useful Signal ◽  
Optimal Values ◽  
Tuning Frequency

 Introduction: We discuss the problem of correlated noise suppression by adaptive complex notch filters of various orders. In order to eliminate the dependence of the transmission coefficient of the useful signal on its frequency, the pulse repetition period is modulated. Purpose: Studying the influence of pulse repetition period modulation on the correlated noise suppression coefficient. Methods: The notch filter parameters were optimized with the criterion of minimum average dispersion of correlated noise at the output of the filters during the repetition period modulation. Results: Expressions are obtained for the variance of correlated noise at the output of complex adaptive filters of various orders when the repetition period is modulated. Relationships are given for finding the optimal values ​​of the tuning frequency and coefficients of the notch filters which minimize the correlated noise level at their output. Expressions are obtained for the coefficients of correlated noise suppression by notch filters in the context of pulse repetition period modulation. The graphs are presented showing how the correlated noise suppression coefficient depends on the relative value of the probing signal repetition period deviation for various values ​​of the correlated noise spectral density width at optimal or non-optimal values ​​of the tuning frequency and coefficients of the notch filters. It is shown that the use of probing pulse repetition period modulation leads to a decrease in the correlated noise suppression coefficient. On the other hand, the adaptation of the weighting coefficients for the adopted models of notch filters and correlated interference provides an increase in the suppression coefficient. Practical relevance: When developing or studying correlated noise suppression systems, the obtained results make it possible, taking into account the permissible losses of the suppression coefficient, to reasonably choose the input pulse repetition period deviation value in order to eliminate the effect of “blind” frequencies.

Pulse Repetition Period in a Sequence in the Acoustic Tensometry Definition

2015 ◽  
Vol 58 (1) ◽  
pp. 38-45
Author(s):  
E. A. Bukvarev ◽  
M. V. Martynyuk ◽  
L. A. Pasmanik ◽  
V. A. Smirnov
Keyword(s):  
Pulse Repetition ◽  
Repetition Period ◽  
Pulse Repetition Period

scholarly journals RANGE AND RADIAL VELOCITY MEASUREMENT AMBIGUITY ELIMINATION WITH TRAINS OF MULTICOMPONENT SIGNALS

2020 ◽  
pp. 91-100
Author(s):  
M. V. Buhaiov ◽  
S. P. Samoilyk
Keyword(s):  
Radial Velocity ◽  
Correlation Coefficient ◽  
Cross Correlation ◽  
Frequency Deviation ◽  
Pulse Repetition ◽  
Repetition Period ◽  
Pulse Repetition Period ◽  
Auto Correlation ◽  
Multicomponent Signals ◽  
Chirp Signals

When designing pulse-Doppler radar, one of the key points is the choice of the pulse repetition period, which determines the boundaries of unambiguous measurement of range and radial velocity and creates contradictions in the measurement of these values. This contradiction is especially acute in the analysis of signals reflected from the propellers and turbines of aircraft. The main approaches to solving the problem of expanding the boundaries of unambiguous measurement of range and radial velocity is the use of variable pulse repetition period and the creation of signal ensembles to separate them by shape. Generation of an ensemble of sounding signals for a pulsed radar must be carried out taking into account both cross-correlation and auto-correlation properties. An approach to the generation of multicomponent signal trains with the possibility of pulse separation inside the train is proposed. Each of the pulses in the train is formed by adding a number of chirp signals, which differ in the values of amplitude and frequency deviation. As the frequency deviation increases, the amplitude of the component decreases. Reducing the cross-correlation coefficient of multicomponent signals from the formed ensemble can be achieved by increasing the number of components of each signal. The size of the signal ensemble, which can be formed on the basis of multicomponent chirp signals, depends on the requirements for the cross-correlation coefficient and auto-correlation function of the signals. It is shown that in order to expand the limits of coordinate measurement at a fixed wavelength, it is necessary to increase the number of pulses in the train. The results of the research demonstrate the potential possibility of using the proposed multicomponent chirp signal to form train of pulses with its subsequent separation.

scholarly journals Extraction of the pulse width and pulse repetition period of linear FM radar signal using time-frequency analysis

2020 ◽  
Vol 3 (1) ◽  
pp. 1-8
Author(s):  
Ashraf Adamu Ahmad ◽  
Sagir Lawan ◽  
Mohammed Ajiya ◽  
Zainab Y. Yusuf ◽  
Lawal M. Bello
Keyword(s):  
Pulse Width ◽  
Direct Method ◽  
Additive White Gaussian Noise ◽  
Pulse Repetition ◽  
Radar Signal ◽  
Repetition Period ◽  
Signal To Noise ◽  
Pulse Repetition Period ◽  
Time Frequency ◽  
Instantaneous Power

A common technique used by military to realize low probability of intercept (LPI) is linear frequency modulation (LFM) in the field of electronic intelligence (ELINT). This paper estimates the pulse width (PW) and the pulse repetition period (PRP) of LFM signal using instantaneous powers. The instantaneous powers were obtained either using time-marginal or power maxima approximated from a modified version of the Wigner-Ville distribution (WVD). The instantaneous power was also gotten directly from the signal by multiplication with its conjugate. Measurement was then carried out when the instantaneous power is ‘ON’ (the PW) and when it is ‘OFF’ (the PRP) at carefully selected thresholds. Thereafter, the mWVD-based algorithm was tested in the presence of additive white Gaussian noise (AWGN) at various signal-to-noise ratios. Results obtained during the test showed that the time marginal method emerged the best with minimum signal-to-noise ratio (SNR) of -5dB followed closely by the direct method with minimum SNR of -1dB at different thresholds. The results show that the proposed algorithm based on this modified WVD can be deployed in the practical field to determine radar’s performance and function

scholarly journals AMTI Filter Design for Radar with Variable Pulse Repetition Period

2016 ◽  
Vol 67 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Michal Řezníček ◽  
Pavel Bezoušek ◽  
Tomáš Zálabský
Keyword(s):  
Impulse Response ◽  
Filter Design ◽  
Radar System ◽  
Pulse Repetition ◽  
System Stability ◽  
Repetition Period ◽  
Pulse Repetition Period ◽  
Radar Antenna

Abstract This paper presents a design of a Doppler AMTI filter, for a radar with a variable pulse repetition period (stagger). The filter can suppress ground and volume clutter echoes simultaneously. The maximum filter impulse response length is limited to 5 coefficients due to a limited radar system stability and a radar antenna movement.

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