HYDROACOUSTICS
ANNUAL JOURNAL
START NEW VOL 19 SEARCH STATISTICS PAS - GDANSK DIVISION

Continuous wave sonar with hyperbolic frequency modulation keyed by pseudo-random sequence

pp. 185-196, vol. 19, 2016

Andrzej Jedel
Gdansk University of Technology, Faculty of Electronics, Telecommunications and Informatics, Poland

Jacek Marszal
Gdansk University of Technology, Faculty of Electronics, Telecommunications and Informatics, Poland

Roman Salamon
Gdansk University of Technology, Faculty of Electronics, Telecommunications and Informatics, Poland

Key words: CW FM; pseudorandom sequence; Doppler effect; matched filtering

Abstract: A CW FM type sounding signal is used in the classical solution of silent sonar. While the signal provides a relatively simple implementation of digital signal processing, and ensures good detection conditions, unfortunately, in the presence of the Doppler effect, distance measurement results tend to be wrong. This is due to the fact that the received signal’s instantaneous frequency value is dependent both on the distance to the object, and its speed. Sounding signal, as patented by the authors, is a combination of Pseudo-Random Sequences (PRS), and elementary signals of Hyperbolic Frequency Modulation (HFM) type. The structure of this signal is aimed at minimizing measurement error. The article presents the idea of a sounding signal of HFM+PRS type, and the results of computer simulations.

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© Polish Acoustical Society - Gdansk Department, Polish Academy of Sciences. This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported. (CC BY-NC-SA 3.0)