Simultaneous navigation and mapping (SLAM) of an autonomous underwater vehicle (AUV) based on side-scan sonar data has significant peculiarities that make standard SLAM techniques inapplicable. In particular, recognition of already visited places (loop closure) which is an important tool improving the navigation accuracy cannot be done with the raw sonar data. This and other navigation tasks ca...

In this paper, a mobile robot control law for corridor navigation and wall-following, based on sonar and odometric sensorial information is proposed. The control law allows for stable navigation avoiding actuator saturation. The posture information of the robot travelling through the corridor is estimated by using odometric and sonar sensing. The control system is theoretically proved to be asy...

Traditional system diagnostic and management techniques rely on static system structure and static instrumentation. We believe that static approaches are simply no longer sustainable in today’s complex, distributed and dynamic systems. SONAR (Sustainable Optimization and Navigation with Aspects at Runtime) is a fluid and unified framework that allows stakeholders to dynamically explore and modi...

Background reverberation can obscure useful features of the target echo response in broadband low-frequency sonar images, adversely affecting detection and classification performance. This paper describes a resolution and phase-preserving means of separating the target response from the background reverberation noise using a coherence-based wavelet shrinkage method proposed recently for de-nois...

This paper deals with automatic target tracking in video and sonar subsea sequences, an essential capability for automating tasks currently performed by remotely operated vehicles under pilot control. We describe two trackers, one for video sequences, the other for sector scan sonar sequences. No assumptions are made about the images, scene, or motion observed. To illustrate applications, we re...

Naval sonar has been accused of causing whale stranding by a mechanism which increases formation of tissue N(2) gas bubbles. Increased tissue and blood N(2) levels, and thereby increased risk of decompression sickness (DCS), is thought to result from changes in behavior or physiological responses during diving. Previous theoretical studies have used hypothetical sonar-induced changes in both be...

Conventional sonar ring sensors, which can measure the distance to the nearest objects, are widely used in indoor mobile robots for obstacle avoidance purposes. Meanwhile, in advanced sonar sensing, accurate range and bearing measurement of multiple targets is performed using multiple receivers in each direction, but often regarded as slow due to the intensive computation process of all capture...

While atypical mass strandings of beaked whales have been linked to naval exercises using midfrequency sonar, the causal chain of events from sound exposure to stranding has not been elucidated. We now know that beaked whales react strongly to sonar, killer whale, and bandlimited noise by ceasing echolocation and completing an unusually slow, directional ascent, in many cases leaving area entir...

We describe a technique to determine presence and attention levels of computer users. This technique relies on sonar using hardware that already exists on commodity laptop computers and other electronic devices. It leverages the fact that human bodies have a different effect on sound waves than air and other objects. We conducted a user study in which 20 volunteers used a computer equipped with...

S.G. Nikolov, E. Loke, J.M.H. du Buf Signal and Image Processing Laboratory Department of Electronics and Computer Science University of Algarve, 8000 Faro, Portugal e-mail: fsnikolov, loke, [email protected] ABSTRACT In this paper we describe a new software system for interactive three-dimensional visualisation of sonar data. Novel approaches to 3-D volumetric sonar data reconstruction and segmen...