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In this article, we consider two related aspects of radar resource management, scheduling and task prioritization. Two different methods of scheduling are examined and compared and their differences and similarities highlighted. The comparison suggests that prioritization of tasks plays a dominant role in determining performance. A prioritization scheme based on fuzzy logic is subsequently contrasted and compared with a hard logic approach as a basis for task prioritization. The setting of priorities is shown to be critically dependent on prior expert knowledge. By assessing the priorities of targets and sectors of surveillance according to a set of rules it is attempted to imitate the human decision-making process such that the resource manager can distribute the radar resources in a more effective way. Results suggest that the fuzzy approach is a valid means of evaluating the relative importance of the radar tasks; the resulting priorities have been adapted by the fuzzy logic prioritization method, according to how the radar system perceived the surrounding environment.

This article concerns European cigarette smuggling over the past decade and examines the actors, structures and relationships which facilitated the illicit trade. It discusses the central role played by actors not traditionally associated with organised crime, such as multi-national tobacco companies, Swiss banks and the state security agencies of various Balkan states. It demonstrates how domestic legislation in Switzerland and instability in the Balkans prevented national law enforcement agencies from effectively dealing with this international network at an earlier stage. The article also focuses on the history of local and national law enforcement investigations as well as the integrated multi-national investigation project later initiated by the EU and member states. The article's conclusions suggest that while smuggling actors have successfully adapted to the process of globalisation – financial and state deregulation – law enforcement agencies remain at a disadvantage as they are hampered by the do...

The first interferometric measurements of temporal-coherence length variation with numerical aperture (NA) are described for 650 nm, resonant-cavity light-emitting diodes (LEDs) agreeing with spectrally derived results. The interferometrically measured coherence length (22 /spl mu/m to 32 /spl mu/m) reduced by 37% for a 0.42 increase in NA. For a larger range of NA (0-1), this would give coherence lengths (10 /spl mu/m-40 /spl mu/m) lying in the gap between that of conventional LEDs (/spl sim/5 /spl mu/m) and superluminescent diodes (/spl sim/60 /spl mu/m).

Landmine clearance is a severe and unresolved humanitarian issue. The development of low-cost, smaller, faster and lighter Ground Penetrating Radars (GPR), which can be mounted on unmanned platforms, will allow faster and safer 24/7 operations. This technology will make it possible to survey affected areas with more flexible trajectories and these will provide measurements of landmine signatures from many different aspect angles. As a result, multi-perspective information over wide angular windows and the behaviour of the signature as a function of the angle of illumination can be exploited. Landmine signatures are expected to present features that are less sensitive to the angle of illumination with respect to those of common cluttered objects, and this can lead to an improvement in detection and discrimination performance. In this paper, we present the results of an experimental trial carried out to collect the High Range Resolution Profiles (HRRPs) of two landmines, the SB-33 and the VS-50, off the ground. An analysis of the auto-correlation function of each range bin as a function of the aspect angle is presented together with that of the cross-correlation between profiles collected from different aspect angles.

Conventional passive coherent location (PCL) systems project arriving signals onto a single polarisation state. One justification for this design is that the PCL system has no control over the source(s) of opportunity, which typically radiate in a single fixed polarisation state, and hence there is little or no prospect of determining the target's full polarization scattering matrix. In this paper we demonstrate that dual polarization reception, while not affording the full scattering matrix, can provide substantial gains in target classification performance.

This study discusses the analysis of multistatic micro-Doppler signatures and related features to distinguish and classify unarmed and potentially armed personnel. The application of radar systems to distinguish different motion types has been previously proposed and this work aims to further investigate the applicability of this in more scenarios. Real data have been collected using a multistatic radar system in a series of experiments involving several individuals performing different movements. Changes in classification accuracy as a function of different aspect angle between the direction in which the target faces and the line-of-sight of the radar nodes are analysed. Multiple data fusion methodologies are proposed, showing that significant improvement of the classification accuracy can be achieved when using separate classification at each node followed by a voting procedure to reach the final decision. This is beneficial especially at those aspect angles for which micro-Doppler detection is less favourable.

This paper addresses the problem of allocating resource and selecting operational parameters for multiple tasks for an electronically steered phased array radar system. The continuous double auction parameter selection (CDAPS) algorithm is presented, which controls the operational parameters such that a resource constraint is satisfied. The algorithm optimises the complete multiple task parameter selection problem, in contrast to the common approach of optimising the parameter selection for each single task separately. It is shown that CDAPS produces a near-optimal solution for the single resource discrete parameter selection problem. Simulated scenarios verify that this near-optimum solution significantly improves upon conventional rule based methods. The additional desirable characteristics of the CDAPS algorithm: computational efficiency, scalability, and rapid reaction, are also highlighted.

Dean (2001) found conflicting views among consultant psychiatrists about ‘what is actually meant by having responsible medical officer (RMO) status'. Many clearly feel that they are responsible for virtually all patients referred to secondary care: Tyrer et al (2001) found in a large audit many consultants with big personal case-loads of 200–300 patients. They concluded that the statutory duties of a RMO needed to be revised to avoid consultants merely becoming bureaucratic administrators of their case-load’.

The list of books on the history of radar is a long one. Most concentrate on technology and events, since these tend to be well documented and relatively uncontroversial. But equally, if not more interesting, are the stories of the individuals behind these actions. This is often more difficult, since it involves a good deal of scholarly research from diverse sources and critical analysis to build up a full picture. This book falls into the latter category, and does a splendid job. Its subjects are two characters of British origin who made their mark in Australia.

This paper directly compares sea clutter data gathered from two separate radar systems, Ingara from the Defence Science and Technology Organisation (DSTO) Australia and Fynmeet from the Council for Scientific and Industrial Research (CSIR), South Africa. The key quantitative difference explored in this paper is the difference in grazing angle, which is moderately high (15° – 46°) for the Ingara data and very low (0.1°) for the CSIR data. The results show that the high grazing angle data at comparable azimuth angles with respect to wind and wave direction has a larger K-distribution shape parameter. The correlation properties of the data are also analysed and directly compared.

We continue the evaluation of nontraditional emitters and waveforms to bistatic radio frequency tomography using digital broadcast television signals, and the associated waveform processing. This paper is a sequel to the original work wherein the move-stop-move approximation was employed and the problems of direct signal breakthrough were covered. Here we evaluate tomographic reconstruction including the effects of platform motion during reception and develop an exact solution to compensate for Doppler. A pseudorandom (PN) binary phase-coded waveform is used to represent the digital, high definition television waveform and justified based upon measured signal examples.

Multistatic radar provides many advantages over conventional monostatic radar, such as enhanced information on target signatures and improvements in detection which are due to the multiple perspectives and differences in the properties of clutter. Furthermore, the fact that receive-only multistatic nodes are passive may be an advantage in military applications. In order to quantify potential performance benefits of these advantages a comprehensive understanding of target and clutter behaviour in multistatic scenarios is necessary. However, such information is currently limited because bistatic and multistatic measurements are difficult to make, their results depend on many variables such as multistatic geometry, frequency, polarization, and many others, and results from previous measurements are likely to be classified for military targets. Multistatic measurements of targets and clutter have been performed over the past few years by the NetRAD system developed at the University College London and the University of Cape Town. A new system, NeXtRAD, is now being developed in order to investigate some of the many aspects of multistatic radar. This paper discusses the results obtained with the previous system and the lessons learnt from its use. These points are then discussed in the context of the new radar, defining key important factors that have to be considered when developing a new multistatic radar system.

X-band measurements of flying sea birds have been carried out in order to investigate the potential of extracting features for target recognition from micro-Doppler signatures. More specifically, the contribution from wings to the bird's total RCS is examined. This is important as these signatures are believed to be highly dependent on aspect angle and polarization. The underlying question is if the contribution from flapping wings in terms of backscattered power is large enough to be detected at all aspect angles. As modern surveillance radar systems will have increased sensitivity compared to their predecessors, more birds are expected be detected. So what SNR would be required to not only detect, but extract recognizable features from micro-Doppler signatures at any aspect angle as well?

There has been considerable research into analytical modeling of bistatic sea clutter However, such models have generally not been validated against measured data. A comparison between low grazing angle simultaneously recorded out-of-plane bistatic and monostatic S-band sea clutter and electromagnetic simulation is presented in this paper. Both vertical and horizontal polarizations were recorded and the bistatic angle was varied from 60° – 120°. The simulation results were in agreement with the measurement in the monostatic geometry and there were significant differences in the bistatic geometry.

This report presents work undertaken on Multistatic Radar Sea Clutter over the period October 2012 to April 2014. A number of topics have been addressed as follows: (1) NATO SET-185 is a research collaboration panel on sea clutter involving 9 nations. UCL has participated in collaborative work and meetings supported by this grant. (2) Low grazing angle sea clutter models. Differences between existing empirically derived models for average sea clutter backscatter have been investigated and compared with Propagation and EM scatter modeling. A number of potential explanations for the differences are proposed. (3) Multistatic radar measurement accuracy. The evaluation of measurement accuracy for a multistatic radar system is a difficult and complicated task. Work has been undertaken to derive a straightforward method, which is presented in this report.

Summary form only given. The RF electromagnetic spectrum, extending from below 1 MHz to above 100 GHz, represents a precious resource. It is used for a wide range of purposes including communications, radio and television broadcasting, radio navigation, and sensing. Radar represents a fundamentally important use of the EM spectrum, in applications which include air traffic control, geophysical monitoring of Earth resources from space, automotive safety, severe weather tracking, and surveillance for defence and security. Nearly all services have a need for greater bandwidth. As the demand continues to grow for more access to spectrum by all these interested parties, there will be ever-greater competition for this finite resource. At the same time, modern digital signal processing techniques allow precise wide-bandwidth radar waveforms to be generated, with high spectral purity and whose properties can be varied adaptively, and this capability forms the basis of the subject of waveform diversity. The purpose of this tutorial, which is based on the work of NATO SET-179 and SET-182 Task Groups, is to describe and explain current work in spectrum engineering and waveform diversity.

Recent experimental results have shown that the statistical properties of bistatic radar clutter are a function of the bistatic geometry. This suggests that it should be possible to choose the bistatic geometry to best exploit this effect. This idea has been named “clutter diversity.” The presentation will elaborate on the effect, and the improvement in performance that its exploitation may bring.

Nature provides a number of examples where acoustic echolocation is the primary sensing modality, the most well known of these being the bat, whale, and dolphin. All demonstrate a remarkable ability to “see with sound.” Using echolocation, they navigate, locate, and capture prey. As species, they have not only survived but have thrived in all their individual environments, often solely reliant on echolocation. All of these creatures are inherently cognitive. They all maintain a perception of their environment through the nervous system that allows them to take actions. In this paper, we focus on the bat as an example of a cognitive system exploiting a memory-driven perception-action cycle, enabling it to navigate and interact with its environment. The key conceptual components of cognition and how it could be applied to man-made echoic sensors is introduced. This is followed by a description of how echoic flow fields, a bio-inspired technique that bats have been shown to use, fit guidance, and control problems. We then go on to explain how bats are able to reliably distinguish between different targets. A combination of the theory and examples is used to demonstrate the vast potential for advancing the capability of made in man-made systems by adopting aspects of natural echolocating cognitive dynamic systems.

MIMO radar should not be regarded as a separate subject, but rather as part of a continuum of different types of diverse, networked radar sensors.

There is a need for a framework to manage the conflicting priorities faced by mental health services. Neither people with severe, enduring and disabling mental health problems, nor the larger numbers with less disabling but perhaps equally distressing problems must be disadvantaged. The framework needs to be acceptable to and usable by health and social services commissioners and primary and secondary care providers. The development of a tiered approach to mental health needs and services is described, along with the intended benefits and current problems. Relationships between this approach and other frameworks are outlined. Progress in implementing and evaluating the approach so far is described.

Recent studies in English cities have shown increases in admissions to acute psychiatric wards. There have been particular increases in admissions of young men, people with drug problems, and out-of-hours admissions. The present study compared hospital record data using 6 months' admission cohorts from 1990, 1993 and 1996 to investigate whether these changes have occurred in rural areas, and whether they represent continuing trends. The results showed significant steady upward trends in the numbers of young men, drug-related problems, accident and emergency referrals, and out-of-hours admissions. It is concluded that the pattern of psychiatric admissions is changing in rural as well as urban England, and these changes should inform the planning of future services.

The failure of many conflict resolution interventions in the 1990s suggests the need for new research approaches into the dynamics of internal conflict. This article attempts to identify adversarial forces facing those charged with conflict resolution in Bosnia‐Herzegovina. It argues that the adversary is not a series of individuals as is often supposed, but rather a politico‐economic structure which has survived the end of open conflict. Focus is placed on the mechanics of violence with particular emphasis on the economic dimensions of ethnic cleansing, subsequent trading patterns and the political relationships within ethnically altered societies. Transnational criminal networks and parallel economies are identified as leading agencies within a structure which maintains legitimacy through the doctrine of ethno‐nationalism and the manipulation of the politically and economically disenfranchised.

Why should doctors be involved in management? Given the complexity of mental health services and the considerable challenges for more change, it is hardly credible that the intended benefits for individual patients can be realised without some clinicians taking active roles as managers. Many of

Passive bistatic radar (PBR) is the name given to a bistatic radar that makes use of emissions from broadcast, communications or radionavigation transmitters rather than a dedicated, co-operative radar transmitter. Such systems have a number of potential advantages. The receiver is passive and so potentially undetectable. There are many illumination sources that can be used, many of them of high power and favorably-sited. PBR receiver systems can often be rather simple and low cost, and there is no need for any licence for the transmitter. However, since the waveforms are not explicitly designed for radar use they may be far from optimum for radar purposes. It is therefore necessary to understand the effect of the waveform on the performance of the passive bistatic radar, so as to be able to choose the most appropriate illuminator, and to process the waveform in the optimal way. This chapter describes the properties of such sources, the processing techniques that are used, and the performance that may be achieved.

The simultaneous bistatic and monostatic Doppler signatures of a small boat are measured and analyzed. The data was recorded using the UCL NetRAD 2.4 GHz netted radar system. Two datasets are presented: one at small bistatic angle (~ 4°) and the other at a larger angle (~ 91°). There was little difference between the monostatic and bistatic channels in the former, while there were significant differences in the latter. In addition, by using detections from both channels the true velocity of the target is estimated.

In this chapter we aim to exploit experience of the natural world in which echolocating mammals are able to detect and classify objects with apparent ease. These observations suggest that waveform diversity and orientation strategies play an important role. It is this hypothesis that we test and show to be valid, as confirmed through real-world radar experiments. Specifically, there is additional information contained in different perspectives of a target that can help classify it, thus boosting performance. There is also a law of diminishing returns, in that the opportunity to extract additional new information reduces as the number of perspectives increases.

This paper applies a recently developed sea clutter Doppler simulation model to five sets of data selected from the CSIR 2007 sea clutter database. Each dataset is characterised using the parameters required for the new simulation model. These parameters are then compared between datasets, before the model is then used to generate spectra for each dataset. The effectiveness of the model is discussed and evaluated through comparing the statistics of the simulated data to the real data. It is shown that the fit is suitable for modelling of clutter characteristics that can then be used to understand likely detection performance in a radar. A linear relationship is also shown between two of the parameters used, which shows that it might be possible to reduce these to a single independent parameter.

The RF spectrum, from below 1 MHz to above 100 GHz, represents a precious and strictly finite resource. It is used for a wide range of purposes including communications, radio and television broadcasting, radionavigation, and radar. All users have a need for greater bandwidth. As the demand from all of these users continues to grow for more access to spectrum, there is ever-greater competition for this resource. Radar represents a fundamentally important use of the EM spectrum, in applications which include Air Traffic Control, marine navigation, geophysical monitoring of Earth resources from space, automotive safety, weather tracking, as well as numerous applications in defence and security. The purpose of this paper is to explain the nature and severity of the spectrum congestion problem, and to describe a number of possible approaches to its solution, both from regulatory and technical points of view.

We study the radar signature of a new type of wind turbine, named the Wind Lens. This design includes a flanged shroud around the turbine which concentrates the wind flow past the turbine blades and hence improves the efficiency. The design also offers improved safety, and reduces acoustic noise. Furthermore, it may offer a significantly lower radar signature, which may make the design much more attractive for use in situations where conventional wind turbine designs may disturb the operation of radars. We present the results of an experimental trial, carried out in the UK, to measure the Radar Cross Section (RCS) of a 5 kW Wind Lens turbine prototype and we provide a reference database that can be used for comparing the Wind Lens RCS with that of conventional turbines. We investigate methods to further reduce the Wind Lens RCS and present the results of a time-varying Doppler analysis. Results show that the addition of a metallic mesh around the shroud obscures the rotating blades, and hence mitigates the RCS by 15 dBm2, at angles where the radar interference is highest. (5 pages)

A novel scheme to achieve three-dimensional (3D) target location in bistatic radar systems is evaluated. The proposed scheme develops the additional information of the bistatic radar, that is the transmit angles, to estimate the 3D coordinates of the targets by using multiple-input multiple-output techniques with a uniform circular array on transmit and a uniform linear array on receive. The transmit azimuth, transmit elevation angles and receive cone angle of the targets are first extracted from the receive data and the 3D coordinates are then calculated on the basis of these angles. The geometric dilution of precision which is based on the root Cramer-Rao bound of the angles, is derived to evaluate the performance bound of the proposed scheme. Further, an ESPRIT based algorithm is developed to estimate the 3D coordinates of the targets. The advantages of this scheme are that the hardware of the receive array is reduced and the 3D coordinates of the targets can be estimated in the absence of the range information in bistatic radar. Simulations and analysis show that the proposed scheme has potential to achieve good performance with low-frequency radar.

In recent years there have been two significant and related developments that seem set to lead to new and improved radar capability. These are: (i) diversity, in the form of highly flexible digital technology and (ii) the early adoption of intelligent or cognitive processing techniques. Together these provide a powerful combination that are helping to pave the way to intelligent adaptive radar networks. In this paper we examine the relative merits of different forms of network and how they provide for improvements in radar performance. In addition we review systems, found in nature that can provide a route to synthetic intelligence exploitable in the adaptive radar network of the future.

We describe and discuss some of the current challenges facing radar that result from continued spectral encroachment, which necessitating enhanced robustness to interference, agile waveform-diverse operation, and greater synergy between the signal processing and the physical radar/environment. Subsequently, specific research topics are suggested in which spectrum engineering and waveform diversity may yield viable solutions. In so doing, this paper also provides an introduction to the special session on radar spectrum engineering and waveform diversity affiliated with NATO Task Groups SET-182 and SET-179, respectively.

In this paper we introduce a novel non-parametric depth-based method for the target detection problem in noisy environments under nominal signal-to-noise ratios. Specifically, a distributed sensor network comprised of multiple transceivers is considered. Each sensor is able to transmit and receive a single tone; which is passed to a super sensor where the data is formed into a multistatic response matrix via a pre-detection fusion algorithm. An algorithm is introduced for the determination of the presence of a target in the background medium. The detection performance versus signal-to-noise ratio is developed for a given false alarm rate and compared to a typical monostatic sensor. The depth-based method is shown to improve upon the performance of a single sensor by a considerable margin.

When the National Health Service (NHS) was born in 1948, there was no specific agenda for clinical quality, which was assumed to be inherent in the system. The received wisdom was that good professional training with self-regulation and appropriate opportunities for ongoing professional development all inevitably added up to high-quality health care. Unfortunately, as we now know, this was not and is not true. What quality initiatives there were tended to be disconnected, with duplication, inefficiency and complicated processes all too often the result. Understanding of the relationships between structures, processes and outcomes improved in the 1970s, but in the 1980s, effort was arguably constrained by a prominent emphasis on organisational performance and cost containment.

Accurate imaging of ischemic penumbra is crucial for improving the management of acute stroke patients. T2* magnetic resonance imaging (MRI) combined with a T2*oxygen challenge (T2*OC) is being developed to detect penumbra based on changes in blood deoxyhemoglobin. Using 100% O2, T2*OC-defined penumbra exhibits ongoing glucose metabolism and tissue recovery on reperfusion. However, potential limitations in translating this technique include a sinus artefact in human scans with delivery of 100% OC and relatively small signal changes. Here we investigate whether an oxygen-carrying perfluorocarbon (PFC) emulsion can enhance the sensitivity of the technique, enabling penumbra detection with lower levels of inspired oxygen. Stroke was induced in male Sprague-Dawley rats ( n =17) with ischemic injury and perfusion deficit determined by diffusion and perfusion MRI, respectively. T2* signal change was measured in regions of interest (ROIs) located within ischemic core, T2*OC-defined penumbra and equivalent contralateral areas during 40% O2± prior PFC injection. Region of interest analyses between groups showed that PFC significantly enhanced the T2* response to 40% O2 in T2*-defined penumbra (mean increase of 10.6 ± 2.3% compared to 5.6 ± 1.5% with 40% O2, P2*OC technique for identifying penumbra in acute stroke patients.