Robotics research is dependent on intelligent, fast, accurate, reliable and cheap sensors. Sonar sensing can fulfil these requirements. Moreover sonar physics provides robotics researchers with a natural selection capability for landmark detection in navigation problems. This paper presents a new sonar system that produces accurate measurement and on-the-fly single cycle classification of plane...

Many species of bat emit acoustic signals and use information carried by echoes reflecting from nearby objects to navigate and forage. It is widely documented that echolocating bats adjust the features of sonar calls in response to echo feedback; however, it remains unknown whether audiovocal feedback contributes to sonar call design. Audiovocal feedback refers to the monitoring of one's own vo...

Both the rough air-sea interface and entrapped air bubbles due to wave breaking scatter sound in all directions and contribute to so-called reverberation in active sonar. There are monostatic sonar systems where the source and receiver are at the same position, bistatic sonar systems where the source and receiver are separated, and multistatic sonar systems involving multiple sources and receiv...

A conventional sonar ring measures the range to objects based on the first echo and is widely used in indoor mobile robots. In contrast, advanced sonar sensing can produce accurate range and bearing (incidence angle) measurements to multiple targets using multiple receivers and multiple echoes per each receiver at the expense of intensive computation. This paper presents an advanced sonar ring ...

We present briefly a survey of caracteristics and problems met in the modelling of underwater acoustic noises, in the frame of passive sonar.

Polynomial-phase signals have applications including radar, sonar, geophysics, and radio communication. Of practical importance is the estimation of the parameters of a polynomial phase signal from a sequence of noisy observations. We derive closed form formulae for the Cramér-Rao lower bounds of these parameters under the assumption that the noise is additive white and Gaussian. This is achiev...

In processing of sonar data, beamforming process plays a central role in reducing the effects of the surface and bottom reverberation. In shallow water environments where the reverberation is dominant, target detection from the beamformed results is not effective and may lead to significantly high false alarm rate. This paper presents a novel approach for postprocessing sonar beamformed imagery...

This paper demonstrates that sonar images correlate badly because target geometry and image fringes correlate in different coordinate systems. It is shown that if the receiver is a line array, all point objects have the same image in a coordinate system with axes of range and the sine of target bearing (the (r, s) coordinate system). Results from an ocean experiment are presented. The ocean exp...

The problem of extracting spectral lines from sonar images is treated using a complete scheme that combines an edge detector with a line tracing process. Comparative performance results confirm the efficiency and the reliability of the proposed approach.