Abstract: Sidescan images of the sea-floor usually suffer from artefacts caused by the attitude variations of the towed platform. In collaboration with DFREMER, we are designing a system that compensates for yaw, pitch and roll in real time, i.e. during the whole ping cycle. The 4 m long antenna

alternate sonar transmit signals that retain the required information content but with less effect. OBJECTIVES To achieve the long-term goals, a number of scientific and technological objectives have been identified. These include extending existing finite-element-method (FEM) code to describe acoustic

sonar, even though the wave conditions were unusually calm. Valid measurements of sea surface motion were obtained over the range interval 600 to 1400 m from Flip. A second sonar which transmitted horizontally and scattered from the interior of the mixed layer also sensed surface waves, although

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

Data is presented demonstrating the applicability of sonar-based, clamp-on flow measurement to several, long-standing flow measurement challenges within the oilsands industry, including hydrotransport, coarse tailings, and bitumen froth flow lines. Sonar-based flow measurement technology

, namely: carrying adequate energy for long endurance and range, coping with varying buoyancy, and maintaining accurate navigation throughout missions lasting up to several days. Results from the recent engineering trails are presented, and future missions and development plans are discussed. Keywords:

is to characterize the short and long term variability of signal propagating in the Philippine Sea. A second long term goal is to measure the horizontal directivity of the ambient noise. OBJECTIVES The short term variability useful for charcterizing the performance of a sonar system can be specified

The long-range goals of this research are to improve our ability to characterize the seabed geometry and texture in energetic inner-shelf/bay mouth settings composed of heterogeneous sedimentary material and possessed of dynamic seabed ripples. Our purpose is to improve our understanding of bedform

Convenient and accurate measurement of gas and liquid rates of wet gas mixtures represents a long standing challenge within the oil and gas industry. Recently, sonar-based flow meters have been demonstrated to provide accurate measurement of the mixture flow rate of wet gas mixtures on a clamp

-to-noise ratio is poor. This is usually the case in most passive SONAR problems when early detection and characterization of targets is required. Statistically reliable estimates of the fundamental frequency of a noisy periodic signal can be computed in the frequency domain using Bartlett’s smoothing procedure