Underwater Acoustics Research

The widespread adoption of the Wireless Sensor Networks (WSNs) in various applications in the terrestrial environment and the rapid advancement of the WSN technology have motivated the development of Underwater Acoustic Sensor Networks (UASNs). UASNs and terrestrial WSNs have several common properties while there are…

• SEMA FATMA OKTUĞ

The performance and complexity of signal processing systems for underwater acoustic communications has dramatically increased over the last two decades. With its origins in noncoherent modulation and detection for communication at rates under 100 b/s, phase-coherent digital communication systems employing multichannel…

The scanning acoustic microscope in the reflection mode has proved to be a rather simple and direct means for monitoring the elastic properties of a solid surface. When smooth surfaces of crystalline material are examined in a liquid with a highly convergent sound beam they exhibit a distinct response. This characteri…

A multitransducer, pulse/echo-ranging system is described that differentiates corner and plane reflectors by exploiting the physical properties of sound propagation. The amplitudes and ranges of reflected signals for the different transmitter and receiver pairs are processed to determine whether the reflecting object…

• BİLLUR BARSHAN ÖZAKTAŞ

Although many localization protocols have been proposed for terrestrial sensor networks in recent years, the unique characteristics of the underwater acoustic communication channel, such as high and variable propagation delay and the three dimensional volume of the environment make it necessary to design and develop n…

• ÖZGÜR BARIŞ AKAN

This work presents a detailed review of the development of distributed acoustic sensors (DAS) and their newest scientific applications. It covers most areas of human activities, such as the engineering, material, and humanitarian sciences, geophysics, culture, biology, and applied mechanics. It also provides the theor…

• KIVILCIM YÜKSEL

Summary In recent years, wireless sensor networks (WSNs) have attracted the attention of both the research community and the industry, and this has eventually lead to the widespread use of WSNs in various applications. The significant advancements in WSNs and the advantages brought by WSNs have also enabled the rapid…

• GÜRKAN TUNA

Using traditional sonar arrays may be difficult and impractical in some mission-critical scenarios, because they should be mounted on or towed by a ship or a submersible. Alternatively, underwater acoustic sensor networks (UW-ASNs) offer a promising solution approach. In this paper, a target-tracking algorithm for UW-…

• ÖZGÜR BARIŞ AKAN

Underwater acoustic sensor networking is the enabling technology for a wide range of applications including naval surveillance, oil platform monitoring, earthquake and tsunami forewarning, climate and ocean observation, and water pollution tracking. Underwater sensor nodes with sensing and communication capabilities f…

• SEMA FATMA OKTUĞ

A physical model is presented to explain the interference phenomenon that gives rise to the material-dependent signature obtained from an acoustic reflection microscope. An approximate formula is derived for the peak separation of the characteristic response, and it agrees well with the experimental results.

The use of support vector machines—a new regression procedure in water resources—was investigated for predicting suspended sediment concentration/load in rivers. The method was applied to the observed streamflow and suspended sediment data of two rivers in the USA, which have already been used in earlier studies using…

• MESUT ÇİMEN

A new type of metal-ceramic composite transducer, the "moonie,' has been developed by sandwiching a poled lead zirconate titanate (PZT) ceramic between two specially designed metal end caps. Piezoelectric coefficients an order of magnitude larger than PZT itself are obtained. The metal-ceramic composites are being dev…

• AYDIN DOĞAN