In Underwater Acoustic Sensor Networks (UASN) designing Medium Access Control (MAC) protocol is a challenging issue. This is due to low bandwidth and high propagation delay in UASN. This paper proposes a MAC protocol for UASN called Aloha with Virtual Back off Algorithm (AlohaV). The VBA approach is the collision avoidance mechanism for wireless networks. In this proposed work we use VBA with n...

Mismatch problem has been one of important issues of matched field processing for underwater source detection. Experimental use of MFP has shown that robust range and depth localization is difficult to achieve. In many cases this is due to uncertainty in the environmental inputs required by acoustic propagation models. The paper presents that EMD (Empirical mode decomposition) processing underw...

Underwater gliders have proven to be a powerful tool in oceanography because they are reusable, inexpensive and achieve a high duration. These qualities have made the acquisition of oceanographic data sets more accessible. The purpose of this article is to present a study aimed at modelling an underwater glider in the longitudinal and lateral plane. The proposed glider possesses a single stroke...

Realistic rendering of underwater scenes has been a subject of increasing importance in modern real-time 3D applications, such as open-world 3D games, which constantly present the user with opportunities to submerge oneself in an underwater environment. Crucial to the accurate recreation of these environments are the effects of caustics and godrays. In this paper, we shall present a novel algor...

This paper addresses the target localization problems based on received signal strength (RSS) measurements in underwater acoustic wireless sensor network (UWSN). Firstly, the problems based on the maximum likelihood (ML) criterion for estimating target localization in cases of both known and unknown transmit power are respectively derived, and fast implementation algorithms are proposed by tran...

Simulations have proven to be useful in aiding the research in wireless and underwater sensor networks. Simulations can be very convenient also when planning the development and deployment of an underwater sensor network for a real application. However, in order to achieve trustworthy results and to be able to extract correct conclusions, accurate models and real parameters should be used. This...

This paper presents a concept for a control system for an autonomous underwater vehicle under ice using a “SLOCUM” underwater glider. The project concept, the separate working tasks for the next one-and-a-half years and the first results will be presented. In this context the structure of the obstacle avoidance system and a simulator structure with a sensor and environment simulation as well as...

Abstract For pulse compression characteristics and not easily affected by noise, linear frequency modulation signal are widely used in underwater acoustic communication. This paper analyzes the characteristics of hyperbolic frequency modulation signal over underwater acoustic channels. Compared with linear frequency modulation signal, hyperbolic frequency modulation has the same performance of ...

Development of a robust autonomous Underwater Robotic Vehicle (URV) is a key element to the exploitation of marine resources. An accurate dynamic model is important for both controller design and mission simulation, regardless of the control strategy employed. In this paper, a dynamic model for an underwater vehicle with an n-axis robot arm is developed based on Kane’s method. The technique pro...

Underwater exploration requires mobility and manipulation. Underwater robotic vehicles(UR y) have been employed for mobility, and robot manipulators attached to the underwater vehicle(i.e., rover) play the role of manipulation. Usually, manipulation mode happens when the rover is stationary. URV is then modeled as a passive joint and the joints of the manipulator are modeled as active joints. U...