Coherent integration for imaging and detection using active sonar

Existing sonar systems typically rely on a minimum signal strength of a single echo, which limits their performance in low signal-to-noise conditions. This thesis explores the concept of coherent integration for active sonar, with the aim of improving imaging and detection capabilities under low signal-to-noise conditions. The goal is to provide...

Helicopter SONAR Control: Cable Control for Helicopter Dipping SONAR Operations in Hover using Incremental Nonlinear Dynamic Inversion

Control of a helicopter with a deployed dipping sound navigation and ranging (SONAR) is no trivial task due to the complex dynamics of the suspension cable. The cable can change shape, which influences the effect of water, wind and the motion of the helicopter itself. To control such a system, a control method is needed that can cope with these...

Ultrasonically Powered and Controlled Microsystem for Dual-Wavelength Optogenetics with a Multi-Load Regulation Scheme

This letter presents an ultrasonically powered dual-wavelength optogenetic device that targets simultaneous excitation and inhibition of neural activities, or in a broader sense, optical stimulation in two distinct wavelengths for targeting different populations of neurons. This can be applied to a variety of neurological disorders. The...

Assessing the Performance of the Phase Difference Bathymetric Sonar Depth Uncertainty Prediction Model

Realistic predictions of the contribution of the uncertainty sources affecting the quality of the bathymetric measurements prior to a survey is of importance. To this end, models predicting these contributions have been developed. The objective of the present paper is to assess the performance of the bathymetric uncertainty prediction model for...

Towards Underwater Macroplastic Monitoring Using Echo Sounding

Plastics originating from land are mainly transported to the oceans by rivers. The total plastic transport from land to seas remains uncertain because of difficulties in measuring and the lack of standard observation techniques. A large focus in observations is on plastics floating on the water surface. However, an increasing number of...

Linking the morphology and ecology of subtidal soft-bottom marine benthic habitats: A novel multiscale approach

High-resolution surveying techniques of subtidal soft-bottom seafloor habitats show higher small-scale variation in topography and sediment type than previously thought, but the ecological relevance of this variation remains unclear. In addition, high-resolution surveys of benthic fauna show a large spatial variability in community...

Drift-free Localization of Ship Hull Cleaning Robots on Flat Bottoms: A Sonar-based Framework

Fleet Cleaner B.V. is a Dutch company which deploys a wheeled hull-fixed Remotely Operated Vehicle (ROV) to clean biofouling off the Vertical Sides (VSs) and the Flat Bottom (FB) of the hull of seagoing cargo vessels, while berthed at the harbour. To ensure maximal cleaning coverage, accurate localization to keep track of the robot trajectory on...

Where in the underwater world am I?: Towards underwater Simultaneous Localization And Mapping using Sonar and inertial sensing

Our world is rapidly changing, leading to various technological achievements in diverse areas of expertise. Among the most evolving are autonomous robots, machines and vehicles, enormously extending human capabilities. While this trend became quite familiar for land-based vehicles, innovations in the underwater domain lag behind, mainly due to...

Framework Design and Image Registration for Sonar-Based Underwater SLAM

The startup company Fleet Cleaner has developed a mobile robot, specialized in the hull cleaning of large cargo vessels. Navigation and localization of this robot is currently performed manually. This is a difficult process that is greatly complicated during operation. This is mainly due to the availability of relative positioning sensors only,...

Ship Hull Cleaning Robots: Obstacle Detection Using a Forward Looking Sonar System

Fouling (algae, slime, and barnacles) on the hull of large cargo vessels is undesirable because it increases their frictional drag, resulting in an increased fuel consumption. As a solution, Fleet Cleaner introduced a ship hull cleaning robot that maneuvers on the hull, using powered wheels and magnets. The robot is controlled by a human...

An Ultrasonic Sensor for Human Presence Detection to Assist Rescue Work in Large Buildings

When the fire brigade arrives at a burning building, it is of vital importance that people who are still inside can quickly be found. Smart buildings should be able to expose this location data to the fire brigade working in a smart city. In this paper the feasibility is researched of using ultrasonic sound sensors for human presence detection...

Structural Response of Bow Structures with Sonar Domes

Naval vessels are designed to remain operational in severe conditions, sea-state 6 or higher, and have to maintain a minimum forward speed in these conditions. These seakeeping conditions may result in severe impact loads on the bow of the vessel, called slamming. Sonar domes are often used at naval vessels to detect objects under water and are...

Measurement of sewer sediments with acoustic technology: From laboratory to field experiments

Monitoring sewer sediments is necessary to better understand sedimentation and erosion processes. Sonar is one of the available techniques to proceed to sewer sediment measurements. Extraction of numerical data, implementation of a new algorithm to identify the water-sediment interface, laboratory and field experiments have been done to...

Development of a reserve reconciliation tool for the Hengelo Brine Field

Reserve reconciliation is widely applied in the petroleum and mining industry. By updating the reserves throughout the operation, the remaining reserves can be better quantified and the extraction scheduling optimized. The goal of this study is to develop a reserve reconciliation tool for the Hengelo Brine Field, operated by AkzoNobel Industrial...

Improving riverbed sediment classification using backscatter and depth residual features of multi-beam echo-sounder systems

Riverbed and seafloor sediment classification using acoustic remote sensing techniques is of high interest due to their high coverage capabilities at limited cost. This contribution presents the results of riverbed sediment classification using multi-beam echo-sounder data based on an empirical method. Two data sets are considered, both taken at...

Underwater detection, classification and localisation: Improving the capabilities of towed sonar arrays

The end of the Cold War and the collapse of the Warsaw pact have resulted in a change of operational theatre for the naval forces of the North Atlantic Treaty Organisation (NATO). In particular, the focus of Anti Submarine Warfare forces has shifted from tracking Soviet nuclear ballistic missile submarine in the deep waters of the Atlantic ocean...

Adaptive motion compensation in sonar array processing

In recent years, sonar performance has mainly improved via a significant increase in array ap-erture, signal bandwidth and computational power. This thesis aims at improving sonar array processing techniques based on these three steps forward. In applications such as anti-submarine warfare and mine hunting motion of the sonar needs to be...

Research on Dolphin Sounds