Seminar "Selected Topics in Underwater Signal Processing"

 

Basic Information
Lecturers: Gerhard Schmidt and group
Semester: Summer term
Language: English or German
Target group: Master students in electrical engineering and computer engineering
Prerequisites: Fundamentals of digital signal processing
Registration
procedure:

If you want to sign up for this seminar, you need to register with the following information in the registration form

  • surname, first name,
  • e-mail address,
  • matriculation number,

Please note that the registration period starts xx.xx.2024 at 10:00 h and ends xx.xx.2024 at 23:59 h. All applications before and after this registration period will not be taken into account.

Registration will be possible within the before mentioned time by sending an e-mail with the desired seminar topic, name and matriculation number to This email address is being protected from spambots. You need JavaScript enabled to view it..

Only one student per topic is permitted (first come - first serve).

The registration is binding. A deregistration is only possible by sending an e-mail with your name and matriculation number to This email address is being protected from spambots. You need JavaScript enabled to view it. until Sunday, xx.xx.2024 at 23:59 h. All later cancellations of registration will be considered as having failed the seminar.

Time: Preliminary meeting probably on 28.04.2024 at 10:00 h
Written report due on 14.07.2024
Final presentations probably on 26.07.2024 at 10:00 h
Contents:

Students write a scientific report on a topic closely related to the current research of the DSS group. Potential topics, therefore, deal with digital signal processing related to underwater applications.

Students will also present their findings in front of the other participants and the DSS group.

 

Topics for SS2024

Topic title Description
Methods for Underwater Transducer Characterization

Underwater transducers are used for transmitting and receiving acoustic signals and, therefore, an essential part of every underwater acoustic application, like SONAR (sound navigation and ranging) and underwater communication. Since, in reality, there are no perfect transducers, each one has different properties, which will significantly impact in multichannel signal processing the results. Since these properties only vary a little over time, a beforehand characterization is helpful to improve the performance of the overall system. Often measurement water tanks are used as a low-noise environment, which has the drawback of reflections due to relatively small dimensions. This seminar aims to find and summarize the literature about the characterization of underwater transducers, especially in measurement water tanks and the particular environment it creates.

SONAR target detection
and classification using
neural networks

SONAR systems often produce a basic map of the scanned environment called a Plan Position Indicator (PPI). It is up to the operator to analyse this and identify objects. Besides some conventional detection algorithms, it is also possible to use a specific type of neural network - for example a type of Convolutional Neural Network (CNN) - to take over the task of not only detecting objects using the PPI, but also to determine what kind of object is present using only the shape on the map. The aim of this seminar is to review and summarise the literature on neural network based object detection and classification for SONAR systems.

Doppler effect
and analysis
in SONAR applications

When an underwater target is to be detected by a SONAR system, that is in motion relative to the system, the backscatter signals will undergo a change in their time-domain shape and their spectral properties. This occuring Doppler effect differs for both narrow- and wide-band signals and also depends on the transmitted signal's Doppler sensitivity. Through Doppler analysis, the speed or direction of moving targets can be estimated. The aim of this seminar is to summarize the available literature and give an extensive overview over the Doppler effect in SONAR applications, to differentiate the Doppler properties of signals used for SONAR transmission and to give examples for the use cases of (adaptive) Doppler analysis.

Flow-induced Noise and Signal Separation in Hydroacoustic Array Systems

Hydroacoustic arrays are essential in underwater acoustic applications such as SONAR and underwater communication. However, the presence of flow-induced noise can greatly impact the performance of these systems. This topic will examine the literature on methods for analyzing and reducing flow-induced noise in hydroacoustic arrays. It's aimed at the investigation to find current methods and techniques that are used to separate the noise from the actual sonar signal. The goal of this research is to provide a comprehensive overview of the current state of the art in flow-induced noise mitigation in hydroacoustic array systems and to explore the potential future developments in this field.

Comparison of Different Array Geometries for Multi-Channel SONAR Systems

SONAR (sound navigation and ranging) systems are used to detect underwater targets. To achieve good resolution over long distances, multiple transmitters and receivers are used in arrays in multiple input multiple output (MIMO) systems. In addition to the design of the transmitted signals, an optimal arrangement of the array elements for the subsequent signal processing is also important. The aim of this seminar is therefore to find and summarize literature on the behaviour of different array geometries and to compare them with each other. The literature may also come from other fields (for example RADAR).