A Review on Improving the Autonomy of Unmanned Surface Vehicles through Intelligent Collision Avoidance Manoeuvres

In recent years unmanned vehicles have grown in popularity, with an ever increasing number of applications in industry, the military and research within air, ground and marine domains. In particular, the challenges posed by unmanned marine vehicles in order to increase the level of autonomy include automatic obstacle avoidance and conformance with the Rules of the Road when navigating in the presence of other maritime traffic. The USV Master Plan which has been established for the US Navy outlines a list of objectives for improving autonomy in order to increase mission diversity and reduce the amount of supervisory intervention. This paper addresses the specific development needs based on notable research carried out to date, primarily with regard to navigation, guidance, control and motion planning. The integration of the International Regulations for Avoiding Collisions at Sea within the obstacle avoidance protocols seeks to prevent maritime accidents attributed to human error. The addition of these critical safety measures may be key to a future growth in demand for USVs, as they serve to pave the way for establishing legal policies for unmanned vessels.

Preparing the ground for marine spatial planning in Ireland

Marine spatial planning (MSP) is advocated as a means of managing human uses of the sea in a manner that is consistent with the maintenance of the ecological goods and services of the marine environment. The adoption of a system of MSP is seen as urgent in the face of ever-increasing demands on marine resources. This is particularly so in Ireland with its extensive seas, belatedly being recognised as a significant development resource. MSP is promoted by the European Commission (EC) in a recent Green Paper to which Member States of the Union, including Ireland, generally have responded positively. Arising from this consultative process, the EC has published the 'Blue Book' that commits support for MSP. It has also issued guidelines for an integrated approach to maritime policy. The recently adopted EU Marine Strategy Framework Directive strengthens the case for implementing MSP as it requires each Member State to develop a strategy for its marine resources. There is evidence that a diverse range of stakeholders at national and local levels in Ireland are positively disposed toward MSP but no practical manifestation of the concept is in place, though some preparatory work is underway to facilitate its likely implementation into the future. © 2010 WIT Press.

An automatic COLREGs-compliant obstacle avoidance system for an unmanned surface vehicle

Unmanned surface vehicles are becoming increasingly vital tools in a variety of maritime applications. Unfortunately, their usability is severely constrained by the lack of a reliable obstacle detection and avoidance system. In this article, one such experimental platform is proposed, which performs obstacle detection, risk assessment and path planning (avoidance) tasks autonomously in an integrated manner. The detection system is based on a vision-LIDAR (light detection and ranging) system, whereas a heuristic path planner is utilised. A unique property of the path planner is its compliance with the marine collision regulations. It is demonstrated through hardware-in-the-loop simulations that the proposed system can be useful for both uninhabited and manned vessels.

Combining multi-scale geophysical techniques for robust hydro-structural characterisation in catchments underlain by hard rock in post-glacial regions

Accurate conceptual models of groundwater systems are essential for correct interpretation of monitoring data in catchment studies. In surface-water dominated hard rock regions, modern ground and surface water monitoring programmes often have very high resolution chemical, meteorological and hydrological observations but lack an equivalent emphasis on the subsurface environment, the properties of which exert a strong control on flow pathways and interactions with surface waters. The reasons for this disparity are the complexity of the system and the difficulty in accurately characterising the subsurface, except locally at outcrops or in boreholes. This is particularly the case in maritime north-western Europe, where a legacy of glacial activity, combined with large areas underlain by heterogeneous igneous and metamorphic bedrock, make the structure and weathering of bedrock difficult to map or model. Traditional approaches which seek to extrapolate information from borehole to field-scale are of limited application in these environments due to the high degree of spatial heterogeneity. Here we apply an integrative and multi-scale approach, optimising and combining standard geophysical techniques to generate a three-dimensional geological conceptual model of the subsurface in a catchment in NE Ireland. Available airborne LiDAR, electromagnetic and magnetic data sets were analysed for the region. At field-scale surface geophysical methods, including electrical resistivity tomography, seismic refraction, ground penetrating radar and magnetic surveys, were used and combined with field mapping of outcrops and borehole testing. The study demonstrates how combined interpretation of multiple methods at a range of scales produces robust three-dimensional conceptual models and a stronger basis for interpreting groundwater and surface water monitoring data.

Review of Marine Spatial Planning Best Practice of Relevance to Ireland

Making room for new marine uses and safeguarding more traditional uses, without degrading the marine environment, will require the adoption of new integrated management strategies. Current management frameworks do not facilitate the integrated management of all marine activities occurring in one area. To address this issue, the government developed Harnessing Our Ocean Wealth – An Integrated Marine Plan (IMP) for Ireland. Harnessing Our Ocean
Wealth presents a ‘roadmap’ for adopting an integrated approach to marine governance and for achieving the Government’s ambitious targets for the maritime sector, including: exceeding €6.4 billion turnover annually by 2020, and doubling its contribution to GDP to 2.4% by 2030. As part of this roadmap, Harnessing Our Ocean Wealth endorses the development of an appropriate Marine Spatial Planning (MSP) Framework. One way to develop an MSP Framework is to learn from early adapters. Critical assessments of key
elements of MSP as implemented in early initiatives can serve to inform the development of an appropriate framework. The aim of this project is to contribute to the development of this framework by reporting on
MSP best practice relevant to Ireland. Case study selection and evaluation criteria are outlined in the next section. This is followed by a presentation of case study findings. The final section of the report focuses on outlining how the lessons could be transferred to the Irish context.

Evaluating conditions for transboundary marine spatial planning: Challenges and opportunities on the island of Ireland

Transboundary cooperation is viewed as an essential element of Marine Spatial Planning (MSP). While much of the MSP literature focuses on the need for, and benefits of, transboundary MSP, this paper explores the political and institutional factors that may facilitate the effective transition to such an approach. Drawing on transboundary planning theory and practice, key contextual factors that are likely to expedite the transition to transboundary MSP are reviewed. These include: policy convergence in neighbouring jurisdictions; prior experience of transboundary planning; and good working relations amongst key actors. Based on this review, an assessment of the conditions for transboundary MSP in the adjoining waters of Northern Ireland and the Republic of Ireland is undertaken. A number of recommendations are then advanced for transboundary MSP on the island of Ireland, including, the need to address the role of formal transboundary institutions and the lack of an agreed legal maritime boundary. The paper concludes with some commentary on the political realities of implementing transboundary MSP.

3D Efflux Velocity Characteristics of Marine Propeller Jets

The determination of the efflux velocity is key to the process of calculating the subsequent value of velocity at any other location within a propeller jet. This paper reports on the findings of an experimental investigation into the magnitude of the efflux velocities within the jets produced by four differing propellers. Measurements of velocity have been made using a 3D LDA system with the test propellers operating at a range of rotational speeds which bound typical operational values. Comparisons are made with existing predictive theories and to aid design engineers, methods are presented by which the 3D efflux velocity components, as well as the resultant efflux value, can be determined.

‘“Indelible characters”:Tattoos, Power and the Late Nineteenth-Century Irish Convict Body

Since the late nineteenth-century works of criminologists Lombroso and Lacassagne, tattoos in Europe have been commonly associated with deviant bodies. Like many other studies of tattoos of non-indigenous origin, the locus of our research is the convict body. Given the corporeal emphasis of prison records, we argue that tattoos form a crucial part of the power dynamic. Tattoos in the carceral context embody an inherent paradox of their being a component in the reidentification of 'habitual criminals'. We argue that their presence can be regarded as an expression of convict agency: by the act of imprinting unique identifiers on their bodies, convicts boldly defied the official gaze, while equally their description in official records exacted power over the deviant body. Cursory findings show an alignment with other national studies; corporeal inscriptions in Ireland were more prevalent in men's prisons than women's and associated, however loosely, with certain occupations. For instance, maritime and military motifs find representation. Recidivists were more likely to have tattoos than first-time offenders; inscriptions were described as monotone, rudimentary in design and incorporated a limited range of impressions. Further to our argument that tattoos form an expression of convict defiance of prison authority, we have found an unusual idiosyncrasy in the convict record, that is, that the agency of photography, while undermined in general terms, was manipulated by prison officers.

King David’s City at Khirbet Qeiyafa: Results of the Second Radiocarbon Dating Project

Fifteen samples of burnt olive pits discovered inside a jar in the destruction layer of the Iron Age city of Khirbet Qeiyafa were analyzed by accelerator mass spectrometry (AMS) radiocarbon dating. Of these, four were halved and sent to two different laboratories to minimize laboratory bias. The dating of these samples is ~1000 BC. Khirbet Qeiyafa is currently the earliest known example of a fortified city in the Kingdom of Judah and contributes direct evidence to the heated debate on the biblical narrative relating to King David. Was he the real historical ruler of an urbanized state-level society in the early 10th century BC or was this level of social development reached only at the end of the 8th century BC? We can conclude that there were indeed fortified centers in the Davidic kingdom from the studies presented. In addition, the dating of Khirbet Qeiyafa has far-reaching implications for the entire Levant. The discovery of Cypriot pottery at the site connects the 14C datings to Cyprus and the renewal of maritime trade between the island and the mainland in the Iron Age. A stone temple model from Khirbet Qeiyafa, decorated with triglyphs and a recessed doorframe, points to an early date for the development of this typical royal architecture of the Iron Age Levant.

The inventorying of building stone performance-in-use to assess susceptibility to decay

The Natural Stone Database for Northern Ireland was constructed to address the paucity of information available to stone conservation practitioners within the region. Almost 2000 listed buildings and monuments were surveyed over three years to produce an interactive GIS database. This contained information on stone sources, together with details of stone condition and decay processes. This paper uses elements of this GIS to investigate stone decay patterns across Northern Ireland. The results demonstrate that as the level of stone decay increases, so does the proportion of buildings with sandstone as the primary stone type. It appears that a
higher open porosity level combined with Northern Ireland’s wetter climate and maritime location leads to rapid wetting and drying cycles within sandstones. This is coupled with the ingress and crystallisation of marine and other salts within stone pores leading to considerably
higher rates of decay than for any other stone type.