The aim of this paper is to propose a technique for Simultaneous Localization and Mapping in underwater environments by means of acoustic sensors. The proposed procedure consists in the application of suitable Neural Network and Iterative Closest Point algorithms for objects detection, agent localization and map construction. General Regression Neural Network and improved ICP algorithms are imp...

This paper presents a first detailed case study of collaborative exploration of a substantial environment.We use a pair of cooperating robots to test multi-robot environment mapping algorithms based on triangulation of free space (see video). The robots observe one another using a robot tracking sensor based on laser range sensing (LIDAR). The environment mapping itself is accomplished using so...

| Panoramic sweeps produced by a scanning range sensor often defy interpretation using conventional line of sight models, particularly when the environment contains curved, specularly re ective surfaces. Combining multiple scans from di erent vantage points provides geometric constraints necessary to solve this problem, but not without introducing new di culties. Existing multiple scan implemen...

In this paper, we present mathematical analyses to consider the effect of material properties on the sensitivity of the Microelectromechanical systems (MEMS) piezoelectric hydrophone and improve the sensitivity by choosing the proper material. The selected structure in the present paper is a piezoelectric hydrophone able to work at low frequencies. The piezoelectric hydrophones are widely used ...

Techniques for three-dimensional visualization of a surface ship bubbly wake using a high-frequency narrow beam profiling sonar are reported. Instrumentation, experimental set-up, and data processing are described. An Imagenex profiling sonar is mounted on the side of a boat at about 1 m below the water surface. The narrow pencil beam scans the water through the sectors whose plane is perpendic...

The task of building a map of an unknown environment and concurrently using that map to navigate is a central problem in mobile robotics research. This paper addresses the problem of how to perform concurrent mapping and localization (CML) adaptively using sonar. Stochastic mapping is a feature-based approach to CML that generalizes the extended Kalman lter to incorporate vehicle localization a...

The task of building a map of an unknown environment and concurrently using that map to navigate is a central problem in mobile robotics research. This paper addresses the problem of how to perform concurrent mapping and localization (CML) adaptively using sonar. Stochastic mapping is a feature-based approach to CML that generalizes the extended Kalman filter to incorporate vehicle localization...

This study investigated the effects on rainbow trout (Oncorhynchus mykiss) of exposure to high-intensity, low-frequency sonar using an element of the standard Surveillance Towed Array Sensor System Low Frequency Active (LFA) sonar source array. Effects of the LFA sonar on hearing were tested using auditory brainstem responses. Effects were also examined on inner ear morphology using scanning el...