Thales (United Kingdom)

The radio-frequency (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, radionavigation, and sensing. Radar represents a fundamentally important use of the electromagnetic (EM) spectrum, in applications which include air traffic control, geophysical monitoring of Earth resources from space, automotive safety, severe weather tracking, and surveillance for defense and security. Nearly all services have a need for greater bandwidth, which means that there will be ever-greater competition for this finite resource. The paper explains the nature of the spectrum congestion problem from a radar perspective, and describes a number of possible approaches to its solution both from technical and regulatory points of view. These include improved transmitter spectral purity, passive radar, and intelligent, cognitive approaches that dynamically optimize spectrum use.

This book examines the statistics of radar scattering from the sea surface in terms of their relevance to radar operating in a maritime environment; including remote sensing , surveillance and targeting appliances. A lot of the work in the book iss based on the compound K-distribution model for the amplitude statistics of sea clutter. In addition, the book addresses the specification of performance required by customers and the measurement of performance of systems supplied to customers.

The computations of the high-order partial derivatives in a given problem are often cumbersome or not accurate. To combat such shortcomings, a new method for calculating exact high-order sensitivities using multicomplex numbers is presented. Inspired by the recent complex step method that is only valid for firstorder sensitivities, the new multicomplex approach is valid to arbitrary order. The mathematical theory behind this approach is revealed, and an efficient procedure for the automatic implementation of the method is described. Several applications are presented to validate and demonstrate the accuracy and efficiency of the algorithm. The results are compared to conventional approaches such as finite differencing, the complex step method, and two separate automatic differentiation tools. The multicomplex method performs favorably in the preliminary comparisons and is therefore expected to be useful for a variety of algorithms that exploit higher order derivatives.

Reliable and accurate indoor positioning for moving users requires a local replacement for satellite navigation. An UltraWideBand (UWB) system is particularly suitable for such local systems, including temporary installations supporting emergency services inside large buildings. The requirements for emergencies will be very variable, but will generally include: good radio penetration through structures, the rapid set-up of a stand-alone system, tolerance of high levels of reflection, and high accuracy. The accuracy should be better than 1 m, as sometimes it matters which side of a door you are, and locations should be in 3 dimensions. Support for robots as well as people would call for still better accuracy. Rapid set-up implies very little surveying of the fixed terminals, and positioning relative to the mobile and fixed terminals. A radio system that measures ranges between fixed and mobile terminals matches these requirements, but the requirements for accuracy and for dealing with multipath need a bandwidth of more than 1 GHz. Thus UWB is the preferred solution, as it has the specific advantage of high accuracy, even in the presence of severe multipath. This paper presents the features and system design options for UWB positioning systems, and shows how they match the indoor location demands of emergency services. The main features that are covered are: the deployment of terminals (how many, and where), the minimum requirements for fixed terminal surveying, integration (hybridisation) with GNSS, and solving for position inside the network. The main system design options are: whether the mobile terminals are transceivers or solely receivers, the UWB signal design and frequency span, and the use of the same signal for communications. The paper includes results from a demonstration UWB indoor positioning system being built at TRT (UK).

This paper describes a new technique for modeling and simulating the coherent returns from radar sea clutter, based on the compound K-distribution model for clutter amplitude statistics. Using observations of recorded Doppler spectra, a simple method is proposed for characterizing the temporal variations of the Doppler spectrum observed in a single-range cell. It is shown that simulations based on this model can reproduce the main statistical features observed in real measurements.

Multibeam satellite networks in Ka band have been designed to accommodate the increasing traffic demands expected in the future. However, these systems are spectrum limited due to the current spectrum allocation policies. This paper investigates the potential of applying cognitive radio techniques in satellite communications (SatCom) in order to increase the spectrum opportunities for future generations of satellite networks without interfering with the operation of incumbent services. These extra spectrum opportunities can potentially amount to 2.4 GHz of bandwidth in the downlink and 2 GHz of bandwidth in the uplink for high density fixed satellite services (HDFSS).

In 2006, Hao and Zieliński proposed a two-round anonymous veto protocol (called AV-net), which provided exceptional efficiency compared to related techniques. In this study, the authors add a self-tallying function to the AV-net, making it a general-purpose voting protocol. The new protocol works in the same setting as the AV-net – it requires no trusted third parties or private channels, and participants execute the protocol by sending two-round public messages. Compared with related voting protocols in past work, this is significantly more efficient in terms of the number of rounds, computational cost and bandwidth usage.

As the Internet evolves toward the global multiservice network of the future, a key consideration is support for services with guaranteed quality of service. The proposed differentiated services framework is seen as the key technology to achieve this. DiffServ currently concentrates on control/data plane mechanisms to support QoS, but also recognizes the need for management plane aspects through the bandwidth broker. In this article we propose a model and architectural framework for supporting DiffServ-based end-to-end QoS in the Internet, assuming underlying MPLS-based explicit routed paths. The proposed integrated management and control architecture will allow providers to offer both quantitative and qualitative services while optimizing the use of underlying network resources.

During summer 2013 we installed a network of 19 GPS nodes at the ungrounded margin of Helheim Glacier in southeast Greenland together with three cameras to study iceberg calving mechanisms. The network collected data at rates up to every 7 s and was designed to be robust to loss of nodes as the glacier calved. Data collection covered 55 days, and many nodes survived in locations right at the glacier front to the time of iceberg calving. The observations included a number of significant calving events, and as a consequence the glacier retreated ~1.5 km. The data provide real-time, high-frequency observations in unprecedented proximity to the calving front. The glacier calved by a process of buoyancy-force-induced crevassing in which the ice downglacier of flexion zones rotates upward because it is out of buoyant equilibrium. Calving then occurs back to the flexion zone. This calving process provides a compelling and complete explanation for the data. Tracking of oblique camera images allows identification and characterisation of the flexion zones and their propagation downglacier. Interpretation of the GPS data and camera data in combination allows us to place constraints on the height of the basal cavity that forms beneath the rotating ice downglacier of the flexion zone before calving. The flexion zones are probably formed by the exploitation of basal crevasses, and theoretical considerations suggest that their propagation is strongly enhanced when the glacier base is deeper than buoyant equilibrium. Thus, this calving mechanism is likely to dominate whenever such geometry occurs and is of increasing importance in Greenland.

Some of the work carried out within the European integrated project Integrated Photonic mm-Wave Functions for Broadband Connectivity (IPHOBAC) on the development of photonic components and radio-over-fiber technologies for broadband wireless communication is reviewed. In detail, 60 GHz outdoor radio systems for >10 Gbits/s and 60 GHz indoor wireless systems offering >1 Gbit/s wireless transmission speeds are reported. The wireless transmission of uncompressed high-definition TV signals using the 60 GHz band is also demonstrated.

Marte (A UML Profile for Modeling and Analysis of Real-Time and Embedded systems) is a new UML profile extension for real-time and embedded systems, which is going to be standardized by mid 2007 at OMG (Object Management Group). This standard has been proposed by the "ProMarte" consortium, which consists of OMG end-users, tool providers and academics. Marte defines concepts in terms of UML extensions needed to model and analyze real-time and embedded systems (RT/ES). The Marte specification provides an annex which handles its relation to AADL-based models, and the way it may represent them.. Our purpose in this paper is to describe this relation. Our constructions will be presented and illustrated through some examples.

To reduce probability of intercept, in most cases, the form and magnitude of the radar transmissions are designed to spread energy over as wide a range of dimensions as possible. Equally, in response to this, designs for electronic surveillance measures (ESM) systems have been postulated that increase receiver sensitivity. Their purpose is to increase detection range beyond that of the radar (or to an adequate range if they are to be forward deployed). The authors examine the evolving nature of the relationship between advanced ‘low probability of intercept’ (LPI) radar designs and future trends in ESM receiving capability. This relationship is far from straightforward, being both probabilistic and dependent on environmental and operational factors. Indeed this is complicated still further by the issue of affordability. The authors compute the performance of ESM and radar systems for a number of cases, including not just simple interception, but also the extraction of information from intercepted signals. In this way the key factors influencing the detectability of LPI radar systems are determined. It is demonstrated that it is never possible to be completely certain that a radar system has not been detected and that the most appropriate way to implement an LPI radar design is always closely related to the tactical environment in which the radar system will be used. Indeed this often overrides the technical aspects of system performance.

Frequency agility is an important feature when radar operates in jammed environments. With the development of the orthogonal frequency division multiplexing (OFDM) waveform in the communications, the opportunity for a new generation of digital agile radar rises. Old and expensive multi-channel analog agile front ends could be replaced by simpler and cost effective single channel transceivers where the coherent switches in frequency are done digitally. The novelty of the paper is to investigate an agile OFDM waveform so that Doppler can be solved despite the apparent frequency agility. The OFDM performance is assessed from the radar point of view, using the ambiguity function as a tool. Our approach considers a pulse burst, each pulse being implemented with OFDM chips. Three patterns for frequency agility from pulse-to-pulse are studied. Preliminary suggestions to accomplish coherent processing in an agile context are derived.

We consider Time Petri Nets (TPN) for which a firing time interval is associated with each transition. State space abstractions for TPN preserving various classes of properties (LTL, CTL and CTL∗) can be computed, in terms of so called state classes. Some methods were proposed to check quantitative timed properties but are not suitable for effective verification of properties of real-life systems. In this article, we consider subscript TCTL for TPN (TPN-TCTL) for which temporal operators are extended with a time interval, specifying a time constraint on the firing sequences. We prove the decidability of TPN-TCTL on bounded TPN and give its theoretical complexity. We propose a zone-based state space abstraction that preserves marking reachability and traces of the TPN. As for Timed Automata (TA), the abstraction may use an over-approximation operator on zones to enforce the termination. A coarser (and efficient) abstraction is then provided and proved exact w.r.t. marking reachability and traces (LTL properties). Finally, we consider a subset of TPN-TCTL properties (TPN-TCTLS) for which it is possible to propose efficient on-the-fly model-checking algorithms. Our approach consists in computing and exploring the zone-based state space abstraction. On a practical point of view, the method is integrated in Romeo [Gardey et al. (2005, Proceedings of 17th International Conference on CAV’05, Vol. 3576 of Lecture Notes in Computer Science, 418–423)], a tool for TPN edition and analysis. In addition to the old features it is now possible to effectively verify a subset of TCTL directly on TPN.

We present low-complexity, quickly converging robust adaptive beamformers, for beamforming large arrays in snapshot deficient scenarios. The proposed algorithms are derived by combining data-dependent Krylov-subspace-based dimensionality reduction, using the Powers-of-R or conjugate gradient (CG) techniques, with ellipsoidal uncertainty set based robust Capon beamformer methods. Further, we provide a detailed computational complexity analysis and consider the efficient implementation of automatic, online dimension-selection rules. We illustrate the benefits of the proposed approaches using simulated data.

The display of 3D images containing all the depth cues required by the human vision system can be achieved using a reconfigurable Computer Generated Hologram (CGH) with high pixel count. Giga-pixel scale displays or spatial light modulators are required in order to form directly viewable 3-D images of 0.5m in size. A new Spatial Light Modulator (SLM) solution, Active Tiling (AT)¹, has been developed by the authors to replay giga-pixel scale CGHs at video refresh rates. This has overcome a key bottleneck preventing commercial development of electro-holography to date. At the heart of an AT system is a set of replication optics which produces multiple images of an electrically addressed Spatial Light Modulator (SLM) on an optically addressed spatial light modulator (OASLM). Solutions employed within electronic holography will be discussed. A holographic 3D display system using a 4 channel Active Tiling modulator with a new replay optics system has demonstrated directly viewable 3-D images and animations from 100 Mega-pixel CGH data. This provided viewing of both horizontal parallax only (HPO) and full parallax 3-D images up to 140mm in size.

A UML profile for Modeling and Analysis of Real-Time and Embedded systems (MARTE) has been recently standardized by the OMG. This initiative meets the needs of several Thales divisions (e.g., aerospace, land and joint and air systems), which develop real-time and embedded systems. CEA LIST, INRIA and Thales have been the main contributors to the MARTE standard through the ProMARTE consortium. To foster the deployment of MARTE in Thales divisions, we have launched the development of a case study related to a real-time and embedded system using the MARTE adopted specification. As a first step of this study, we make use of a fictive system—the Josefil challenge—to evaluate whether the profile is applicable to the Thales current systems andsoftware engineering practices. The purpose of this paper is to report on this first stage and outline the next scheduled activities.

Radar backscatter from the sea surface has a significant effect on radar systems operating in a maritime environment. This study considers the application of modelling sea clutter to the design and development of such systems, and addresses the sensitivity of the predicted performance to the choice of model. The typical phases of the life-cycle of a radar system are described, along with how models are used to support the radar development. Different types of model are reviewed and some examples are given of the comparison of their effect on predicted performance. The conclusion is that the differences are important and continue to warrant further investigation.

This paper presents a new, practical infrared video based surveillance system, consisting of a resolution-enhanced, automatic target detection/recognition (ATD/R) system that is widely applicable in civilian and military applications. To deal with the issue of small numbers of pixel on target in the developed ATD/R system, as are encountered in long range imagery, a super-resolution method is employed to increase target signature resolution and optimise the baseline quality of inputs for object recognition. To tackle the challenge of detecting extremely low-resolution targets, we train a sophisticated and powerful convolutional neural network (CNN) based faster-RCNN using long wave infrared imagery datasets that were prepared and marked in-house. The system was tested under different weather conditions, using two datasets featuring target types comprising pedestrians and 6 different types of ground vehicles. The developed ATD/R system can detect extremely low-resolution targets with superior performance by effectively addressing the low small number of pixels on target, encountered in long range applications. A comparison with traditional methods confirms this superiority both qualitatively and quantitatively.

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The cornerstone of building and overall facilities management is accurate and up-to-date monitoring of the context of the enterprise building environment and its surroundings, usually performed by sensors dispersed throughout the premises. Currently, the majority of building management systems is tightly coupled with the sensors that they utilize, restricting their extensibility. The emergence of Wireless Sensor Networks (WSNs) has brought significant benefits as far as monitoring is concerned, since they are more cost-efficient, due to the lack of wiring installations, compared to wired sensor solutions and allow for flexible positioning of the sensors, especially when building retrofitting is concerned. In line with the established move towards integration of enterprise level services, it is beneficial to consider the WSNs within that scope. In this paper, we propose to exploit a service oriented architecture for developing an enterprise networking environment that is used for integrating facilities management applications and building management systems with other operational enterprise functions for the purpose of information sharing and monitoring, controlling, and managing the enterprise environment. The WSN is viewed as an information service provider not only to building management systems but also to wider applications in the enterprise infrastructure. We provide specification and implementation details of the proposed architecture and discuss evaluation planning. </para>