Using Multibeam Echosounders for Multiscale and Interdisciplinary Habitat Mapping on the Dutch Continental Shelf

Because the seafloor is a complex ecosystem, a multidisciplinary approach must be adopted in order to produce comprehensive habitat maps. Such multidisciplinary projects have been lacking for the Dutch area of the North Sea. To address this lack, the Distribution, structure and functioning of low resilience seafloor communities and habitats of...

Improving Capabilities in Modeling Aircraft Noise Sources

Today's globalized world depends on civil air transportation, which has been continuously growing over the last decades. Nevertheless, the sustainability of this expansion is a challenge due to environmental problems. Along with greenhouse gas emissions, noise represents a severe hazard for human health, and consequently, noise regulations limit...

Optimizing hydrographic operations for bathymetric measurements using multibeam echosounders

Detailed information about the sea and river bed is of high importance for a large number of applications, such as marine geology, coastal engineering, safe navigation and offshore construction. Acoustic remote sensing techniques have become extremely attractive for obtaining bathymetry measurements and for mapping the sediment properties, due...

Acoustic mapping and monitoring of the seabed: From single-frequency to multispectral multibeam backscatter

With the increasing human activities in the marine environment, such as fisheries, dredging, coastal protection or construction of marine infrastructure, seabed sediment and habitat mapping have become highly relevant for the development of sustainable marine management strategies. Compared to traditional mapping methods, primarily based on bed...

High Resolution Imaging of Noise from Novel Integrated Propeller Systems

Humans localize sound incessantly using the ears and it proves to be important of<br/>our awareness. It can also be a cause of annoyance to the community whenever<br/>sound is in the form of noise. Due to increase of wealth, industry, technology and<br/>corresponding globalization there is a large increase of noise. Especially with the<br/...

Microphone arrays for imaging of aerospace noise sources

With the continuous growth in demand for air traffic and wind turbines, the noise emissions they generate are becoming an increasingly important issue. To reduce their noise levels, it is essential to obtain accurate information about all the sound sources present. Phased microphone arrays and acoustic imaging methods allow for the estimation of...

Auralization of Environmental Acoustical Sceneries: Synthesis of Road Traffic, Railway and Wind Turbine Noise

Environmental noise caused by traffic and industrial facilities is a relevant health factor in urban areas, along major traffic routes and in the vicinity of airports. The technique of auralization helps exploring the relationships between sound and its impact on people under fully controlled conditions. Further, by directly addressing the...

Infrasonic Interferometry: Probing the atmosphere with acoustic noise from the oceans

In this thesis, the possibilities of infrasonic interferometry for probing the troposphere and stratosphere with microbaroms are explored. Infrasonic interferometry determines the delay time between two sensors by cross correlating their infrasound recordings. The obtained delay time can be used to estimate the Green’s function, which is the...

Aircraft noise calculation and synthesis in a non-standard atmosphere

The atmosphere modifies the emitted sound waves of an aircraft during propagation and is therefore important in the calculation of noise contours or synthesis. Noise contours present the resulting noise levels on the ground and are, as such, often applied for regulatory purposes. Aircraft noise synthesis is a technique that allows to transform a...

Classifying sediments on Dutch riverbeds using multi-beam echo-sounder systems

The economic importance of the Dutch rivers is very high as they are heavily used for inland waterway transport between the Netherlands and their neighbouring countries. A minimum depth must be guaranteed to keep the rivers navigable but also to ensure that the ships can carry maximum cargo. An attractive system for obtaining information about...

Establishing a sea bottom model by applying a multi-sensor acoustic remote sensing approach

Detailed information about the oceanic environment is essential for many applications in the field of marine geology, marine biology, coastal engineering, and marine operations. Especially, knowledge of the properties of the sediment body is often required. Acoustic remote sensing techniques have become highly attractive for classifying the sea...

Converted waves in shallow marine environments: Modelling and field experiments

The shallow marine subsurface is explored for various engineering purposes e.g. constructing installations and platforms, laying pipelines and dredging for sand. Knowledge of the soil properties is essential to minimize the risks involved with these offshore activities. Energy resources in the form of gas hydrates and hydrocarbon reservoirs are...

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...

The inaudible symphony: On the detection and source identification of atmospheric infrasound

Sound becomes inaudible if it consists of frequencies lower than 20 Hz, i.e. the human hearing threshold, and is called infrasound. Low frequency acoustic signals were first discovered after the eruption of the Krakatoa (Indonesia) in 1883. Due to its low frequency content, this infrasound traveled up to seven times around the globe while...

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...