A sonar system is presented that relies on scanning a single ultrasonic transducer and measuring echo amplitude and arrival times. Bearing angles to targets are estimated far more accurately than the transducer beamwidth as obtained with conventional sonar rings based on the Polaroid ranging module. A Gaussian beam characteristic is fitted using least squares to the amplitudes of corresponding ...

We present an algorithm to distinguish several types of brick walls, picket fences, and hedges based on the analysis of backscattered sonar echoes. The echo data are acquired by a mobile robot with a single-transducer 50 kHz pulse-echo sonar computer-controlled scanning system packaged as its sensor head. For several locations along a wall, fence, or hedge, a fan of backscatter sonar echoes is ...

An experimental ultrasound scanning sonar has been developed that uses a phased ultrasonic transducer array to image objects through the air. The sonar generates arbitrary long duration broadband signals and uses pulse compression to achieve a high range resolution and a high signal to noise ratio. This paper considers using the sonar in an inverse synthetic aperture side-scan configuration, wh...

Four non-invasive methods (three acoustic and one video) were compared to estimate the abundance and vertical distribution of scyphomedusae, using the locally abundant coronate species Periphylla periphylla in Lurefjorden, north of Bergen, Norway, as the test organism. The acoustic methods included single-target quantification by, respectively, a hull-mounted 38 kHz split-beam echo sounder and ...

In this paper, we are interested in inferring the sources of various types of sonar features typically observed by a mobile robot. After a brief discussion of terrestrial sonar sensing, we develop a set of operators that associates arc-shaped features extracted from sonar scans with real world primitives. Our classi cation scheme is probabilistic and is based on empirical data: the condence of ...

The autonomous underwater vehicles (AUV) carry out inspection missions and intervention on known and unknown environments, where it is important to ensure their safety. The ability for obstacle detection and their avoidance during navigation is a requirement for safety. In this article is presented an obstacle detection system for the experimental vehicle Guanay II using mechanical scanning son...

Autonomous underwater vehicles (AUV) perform inspection missions and intervention in known and unknown environments, where it is necessary to ensure their safety. The AUV must have the ability to detect and avoid obstacles in the path of navigation. This article, an obstacle detection system for experimental Guanay II AUV is proposed, using a mechanical scanning SONAR Tritech Micron MK3. Since ...

Feed waste results in increased production costs to the cage fish farming industry and produces negative environmental impacts. A computerized system, consisting of digital scanning sonar and current meter, was developed for monitoring, assessment, and optimization of the fish feeding process. The system can detect and monitor quantity and direction of wasted food pellets and also predict the t...