Results from Developments in the Use of a Scanning Sonar to Support Diving Operations from a Rescue Ship

Abstract

In recent years, widespread use of scanning sonars for acoustic imaging of the seabed surface can be observed. These types of sonars are mainly used with tripods or special booms, or are mounted onboard remotely operated or unmanned vehicles. Typical scanning sonar applications include search and recovery operations, imaging of underwater infrastructure, and scour monitoring. The use of these sonars is often limited to shallow waters. Diver teams or underwater remotely operated vehicles (ROV) are commonly used to inspect shipwrecks, port wharfs, and ship hulls. However, reduced underwater visibility, submerged debris, and extreme water depths can limit divers’ capabilities. In this paper, a novel, nonstandard technique for use of a scanning sonar is proposed. The new application for scanning sonar technology is a practical solution developed on the Polish Navy’s search and rescue ship “Lech.” To verify the effectiveness of the proposed technique, the author took part in four different studies carried out in the southeastern Baltic Sea. The tests were performed using the MS 1000 scanning sonar. The results demonstrate that the proposed technique has the potential to provide detailed sonar images of the seabed and underwater objects before the descent of divers. The divers get acquainted with the underwater situation, which undoubtedly increases the safety of the entire operation. Scanning sonars are unlikely to completely replace the work of divers but may reduce the number and duration of dives. The sonar use technique turned out to be useful when rescuing a crew of a submarine that crashed and settled on the sea bottom as part of a naval exercise. The sonar data obtained during four experimental tests performed in the Baltic Sea prove the validity, usefulness, and significance of the proposed technique, especially from the standpoint of safety of underwater work.

Fault-Adaptive Autonomy in Systems with Learning-Enabled Components

“…In the System Software stack, there is a complete low-level pipeline from sensing to actuation, supplying the inputs for the autonomy and the control output for the AUV. There are complex sensors, including Side Scan Sonars (SSS) for infrastructure mapping [ 22 ], Forward Looking Sonars (FLS) for obstacle avoidance [ 23 ] and altitude measurement, and basic ones such as rotation-per-minute (RPM) and motor current sensors. In the perception block, there are multiple LECs for processing the sensor data (e.g., there is a Semantic Segmentation Convolutional Neural Network (SemSeg CNN) [ 24 ] for SSS and a Long Short-Term Memory Recurrent Neural Network (LSTM RNN) [ 25 ] type for FLS).…”

Radar and Sonar Imaging and Processing (2nd Edition)

“…The subject of using scanning sonars for acoustic imaging of the seabed surface was addressed by Grzadziel in [3]. Such sonars are mainly used with tripods or special booms or are mounted onboard remotely operated or unmanned vehicles.…”

“…However, limited underwater visibility, submerged debris, and extreme water depths can limit divers' capabilities. Grzadziel [3] propose a new nonstandard technique for using scanning sonar. The new application of the scanning sonar technique is a practical solution developed on the Polish Navy search and rescue ship "Lech".…”

“…Another application of sonar in relation to [3] is the process of target tracking for providing information about objects in a specific area, which is one of the key issues affecting the safety of any vehicle moving in water. The main sensor used to track objects underwater is sonar, with one of the most popular configurations being forward-looking sonar (FLS).…”

The Use of USV to Develop Navigational and Bathymetric Charts of Yacht Ports on the Example of National Sailing Centre in Gdańsk

“…After the mounting of all measuring devices on the USV, the sensors were calibrated to verify their correct operation and to eliminate errors. Therefore, for an SBES, three operations were performed [30,31]:…”