Banca de DEFESA: ELIO PITHON SARNO FILHO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ELIO PITHON SARNO FILHO
DATE: 14/06/2023
TIME: 09:00
LOCAL: https://conferenciaweb.rnp.br/webconf/laboratorio-de-sistemas-digitais-ufba
TITLE:

Passive Sonar Signal Processing using the Hilbert-Huang Transform and Intelligent Noise Reduction

KEY WORDS:

Signal processing; intelligent systems, Hilbert-Huang Transform, SONAR

PAGES: 167
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUMMARY:

Ocean science technology plays a key role in military and exploration of the marine environ-
ment, a fact that has been encouraging the development of new methods of processing and
analysis of underwater acoustic signals (UAS). In the specific case of the passive SONAR
(SOund NAvigation and Ranging) system, most techniques used in detection and classification
of vessels in military operations with submarines are based on the short-time Fourier transform
(STFT). However, this spectral analysis method has limitations regarding time-frequency (TF)
resolution, which directly affects the performance in estimating the characteristic parameters of a
vessel, as well as monitoring its dynamic behavior. This doctoral work proposes a spectral analysis
tool with noise reduction based on the technique called Hilbert-Huang transform (HHT). The
main objective of the proposed method is to be used in conjunction with the Detection of Envelope
Modulation on Noise (DEMON), traditionally used in the analysis of passive SONAR signals.
For that, a sequence of three studies was carried out. The aim of the first study was the choice
of the variant HHT to be used instead of STFT, which is used in traditional DEMON analysis.
In the following, the investigation and selection of a noise reduction technique to mitigate this
serious problem associated with the analysis of experimental passive SONAR signals was carried
out and, ultimately, the implementation of the proposed tool, based on the chosen HHT variant
and a intelligent classification system. The results of applying this new method to simulated and
experimental passive SONAR signals, indicate a better performance when compared to those
obtained with the tradicional DEMON analysis, by presenting greater precision and efficiency in
the analysis of static and dynamic parameters of vessels. When applied to experimental signals,
the proposed method proved to have a higher frequency resolution, with an average spectral
width of about 28 times smaller, in addition to presenting an average signal-to-noise ratio of
87,8 dB bigger.

COMMITTEE MEMBERS:
Interno - 1856678 - PAULO CESAR MACHADO DE ABREU FARIAS
Interno - 2506534 - EDUARDO FURTADO DE SIMAS FILHO
Externo ao Programa - 2130353 - RICARDO ARAUJO RIOS - UFBAExterno à Instituição - NATANAEL NUNES DE MOURA JUNIOR - UFRJ
Externo à Instituição - LEVY BOCCATO - UNICAMP