Academic literature on the topic 'Radar Technology'

Closed-circuit television (CCTV) cameras have become a ubiquitous feature of everyday life in the UK over the last thirty years. In this thesis I undertake an examination of the historical, political, social, economic, and technological factors, influencing the development, usage, and widespread dissemination of CCTV in the UK. I focus on the issue of why the UK has become so camera-surveilled, and especially the specific role that the public has played in relation to the development and use of the technology. I examine the historical factors through an analysis of the development of surveillance, policing, and political change, during the 20th and early 21st centuries, and early and contemporary uses of CCTV, situating this in the wider context of a history of the criminal justice system. I also look at the media and policy context in which CCTV has developed and become widespread, with this element of the thesis particularly informed by an analysis of the way in which the public are constructed. Next, I carry out an empirical study exploring public engagement and consultation in relation to, and feelings towards, the installation of CCTV onto two estates in East London as part of a project to expand access to digital services in London. Finally, I give an overview of international experiences of CCTV providing a broader context for the final analysis. I argue that the lack of legislation and regulation at the time of the inception of CCTV allowed its subsequent and rapid proliferation. The initial growth of CCTV also occurred at a time when public debate and engagement in science and technology policy did not take place. Its use as a tool for crime prevention was cemented by a police force looking for a shoulder to share the burden of fighting crime. This coupled with an availability of public money for the installation of CCTV systems, the need for a political solution to rising levels of crime, and an apparently passive public, formed the ideal environment for the rise of CCTV.

Sedan radar började användas under första hälften av 1900-talet har duellen mellan radar och signalspaning pågått. Genom att utnyttja radar har alltid en medveten risk tagits, risken att bli upptäckt av motståndarens signalspaning. Duellen gavs möjlighet att ta en paus då radarsystem med låg uteffekt introducerades på marknaden under slutet av 1980-talet, nu fanns plötsligt en möjlighet att använda radar samtidigt som de samtida signalspaningssystemen inte kunde upptäcka dessa radarsystem. I föreliggande magisteruppsats i krigsvetenskap med militärteknisk inriktning undersöks räckviddsförhållanden mellan dessa radarsystem och signalspaningssystem. Genom scenarier i den marina arenan försöker jag värdera de taktiska vinster en användare av radar med låg uteffekt kan göra. Analysen visar på att det fram till dess att signalspaningssystem med förmåga att upptäcka radar som utnyttjar låg uteffekt finns tillgängligt är det möjligt att nå taktiska fördelar med dessa system.<br>Since the advent of radar during the early 20th century the duel between radar and electronic support measurement systems has been practised. Using radar has always been associated with a risk of being detected by an opponent’s electronic support measurement systems. The duel came to a halt when radar systems using low output power were introduced on the market during the late 1980s, now it was possible to use radar without being detected by contemporary electronic support measurement systems. The present master of science (one year) thesis in war science with specialization in military technology looks into the range relationships between radar and electronic support measurement systems. Through scenarios in the naval domain, I seek to assess the tactical benefits a user of low probability of intercept radar may have. The analysis indicates that until electronic support measurement systems with the ability to detect radar systems using low output power are available it is still possible to gain tactical advantages with such systems.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>The Vessel Traffic Management System is a cooperative effort of the Naval Undersea Warfare Center and the Naval Air Warfare Center Aircraft Division, funded by the OSD's Test Technology Development and Demonstration Program. The project is establishing the capability to acquire ship tracking information from numerous sources (GPS and radar target extractors), and combine them into a comprehensive, integrated view of the range safety target area. The consolidated tracking information will be transmitted to range safety vessel personnel and presented on portable display systems to aid in clearing the surveillance area of unauthorized vessels. The communications module is media independent in that positional and image data can be routed via RF modem, cellular phone, Intranet or Internet, singly or in any combination. The software systems for data acquisition, display and control are also platform independent, with the system under development operating under WindowsNT and Windows95. Additionally, the use of Java and VRML tools permits a user to display data (including three dimensional presentations of the data) without requiring the applications software. This system has numerous applications including range safety, commercial vessel traffic management, port authority and services monitoring, and oceanographic data gathering.

<p>It is important for the military to know as much as possible about how easily detected their vehicles are. One way among many used to detect vehicles is the use of radar sensors. The radar reflecting characteristics of military vehicles are therefor often rigorously tested. With measurements and simulations it is possible to calculate likely detection distances to a vehicle from different angles. This process often produces very large data sets that are hard to analyze.</p><p>This thesis discusses and implements a method for visualizing the detection distance data set and also discusses a lot of related issues with a focus on computer graphics.</p><p>The main concept is called spherical displacement and the idea is to visualize the detection distances as a surface with the imagined vehicle in the center point. Detection is likely inside the surface but not on the outside. This concept is the next step from the colored sphere where the colors represent the detection distance which was previously used.</p><p>The thesis project resulted in a visualization tool that uses the new concept and can handle large data sets. The spherical displacement concept is more intuitive and shows detail better than the colored sphere visualization.</p>

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California<br>Complete real time testing of a telemetry tracking system typically requires the use of a cooperative target operating under conditions specially set up to simulate actual flight scenarios. This is a very expensive, time-consuming process and does not necessarily exercise all of the functions and capabilities available in new digital antenna controllers. This paper introduces Radar Environment Simulator technology and its application to testing of telemetry tracking systems. Measured results are shown, demonstrating that operational environment simulation is a valuable approach to quickly and effectively characterize the real time operation of a telemetry tracking system.

Enemy integrated air defense systems (IADS) using low probability of intercept (LPI) emitters can cause significant problems for suppression of enemy air defense (SEAD) techniques. New threat emitter configurations using low-power random noise modulation have a significant processing gain unavailable to non-cooperative intercept receivers. Consequently, the detection of these emitters can not be accomplished with conventional intercept receiver detection methods. This thesis examines the use of time-frequency, bi-frequency signal detection techniques to identify the parameters of the four types of continuous waveform noise radar recently reported. These include: (a) random noise, (b) noise plus frequency modulation continuous wave (FMCW), (c) noise FMCW plus sine and (d) random binary phase modulation. Quadrature mirror filtering for wavelet decomposition is used to investigate the four types of noise signals in order to extract the signal parameters. The FFT accumulation method for estimating the spectral correlation density function is also used to examine the cyclostationary bi-frequency properties of the waveforms. In addition, the periodic autocorrelation function and periodic ambiguity function are studied to determine the waveform properties in the delay- Doppler offset domain. Results show that non-cooperative intercept receivers can increase their processing gain using these types of signal processing techniques providing a more efficient response time to the threat.

This thesis presents selected research papers and patents written by Simon Watts between 1985 and 2012 on the topic of the modelling of radar sea clutter. This work has been based on the development and exploitation of the compound K distribution model for the amplitude statistics of radar sea clutter. It has covered the development of the model, through the analysis of recorded radar data, to establish its validity over a wide range of conditions and for both coherent and non-coherent radar processing. The work has also developed methods for exploiting the model for improved performance prediction for radar systems, the analysis and development of new detection signal processing schemes and the use of these models for the specification and measurement of radar performance, for the procurement of radar systems. All the work has been undertaken in an industrial environment, motivated by the need to develop improved radar systems to meet customer requirements.

The purpose of low probability of intercept (LPI) radar is, on top of the standard requirements on a radar, to remain undetected by hostile electronic warfare (EW) systems. This can be achieved primarily by reducing the amount of radiated power in any given direction at all times and is done by transmitting longer modulated pulses that can then be compressed digitally in order to retain range resolution. There are multiple different methods of performing pulse compression modifying either the phase or frequency of the transmitted waveform. Another method for attaining LPI properties of a radar is to avoid having a large main lobe in the transmit pattern and instead having lower gain patterns. This then results in a need for post-processing of these patterns by summation of weighted combination of these low gain patterns in order to reform the high gain patterns and thus retain angular resolution. In this work a number of pulse compression waveforms are analysed and compared using their ambiguity properties in order to ascertain which ones can be used in a radar system. They are then used in simulation with GO-CFAR detectors using a variety of analysis tools, specifically the short term Fourier transform (STFT), Wigner-Ville distribution (WVD), quadrature mirror filter bank (QMFB) and spectral correlation density (SCD). Their performance against the detector is based on the rate that the waveforms trigger an alarm and the lower the alarm rate the better the performance. The base reference in terms of performance for these evaluations was set as a triangular FMCW waveform. The results show that the polyphase coded waveforms have good radar and LPI properties in comparison to the FMCW. The frequency hopping codes showed good LPI properties with a large number of frequencies in the sequence but suffer from large ACF side lobes and poor Doppler tolerance. The best LPI results were achieved by a phase coded signal with a random order to its phase terms whilst still maintaining a perfect periodic autocorrelation function (PACF). Potential issues remain with high frequency out of band emission that could lead to a mismatch due to receiver bandpass filtering. The low gain patterns investigated were expanded to include two way patterns for a 2D array and array element tapering. The method works and can be further optimised in order to minimise emissions but adds a significant increase to integration times when the array size grows large.

Dans le domaine du génie civil, la détection et la caractérisation de défauts (décollements, fissures non-débouchantes) sont des éléments importants de diagnostic qui influencent la mise en œuvre de politique d’entretien et de gestion. Les défauts sont représentatifs d’un état d’altération de la structure. Les caractéristiques géométriques de ces défauts (forme, largeur et longueur) ainsi que l’étendue et les cheminements d’eau induits par ces défauts est un indicateur de durabilité des ouvrages important. Cette détection permet de localiser une éventuelle pathologie, d’évaluer l’état de santé de la structure et de prédire son évolution. Dans ce contexte, les systèmes « radar à impulsions », appelé aussi GPR (Ground Penetrating radar) est utilisé depuis une trentaine d’années pour réaliser des opérations de contrôle non destructif dans le flux du trafic. Ils fournissent une mesure en continu de l’épaisseur de la couche de chaussée, mais permettent aussi la détection de décollements significatifs (centimétrique) entre couches, et de déterminer ainsi l’emplacement de contrôles structurels destructifs ultérieurs. Néanmoins, la résolution temporelle des GPR conventionnels ne permet pas de détecter directement des décollements d’interface millimétriques. L’objectif de ce travail est donc de réaliser une détection précoce de ce type de défauts. Ainsi, mes travaux se sont focalisés à la fois sur l'utilisation du radar ultra large bande (RSF) et sur le développement de méthodes d’intelligence artificielle (basées sur l’apprentissage supervisé). Des approches théoriques et expérimentales (dalle de chaussée Cerema et manège de fatigue de l’IFSTTAR) ont été réalisées. Elles ont permis de montrer la faisabilité de détecter des décollements fins dans les chaussées<br>In the field of civil engineering, the detection and characterization of defects (debondings, non-emerging cracks) are important diagnostic elements that influence the maintenance and management of the pavement structure. These defects represent an altered state of the structure. The geometric characteristics of these defects (shape, width and length) as well as their extent and the water seepage induced by these defects are important durability indicators of the structures. This detection makes it possible to locate a possible pathology, to evaluate the state of health of the structure and also predict its evolution. In this context, "pulse radar" systems, also called Ground Penetrating Radar (GPR) have been used for over thirty years to perform non- destructive testing operations in the traffic flow. They not only provide continuous measurement of the thickness of the pavement layer, but also allow the detection of significant (centimetric) inter-layer detachments, and thus determine the location of subsequent destructive structural controls. However, the temporal resolution of conventional GPRs does not allow direct detection of millimeteric interface debondings. Therefore, the objective of this work is to realize an early detection of such defects. My work is thus focused on both the use of ultra-wideband radar (SFR) and the development of artificial intelligence methods (based on supervised learning) to detect thin debondings. Theoretical and experimental approaches (Cerema test pavement slabs and IFSTTAR's fatigue carousel) were realized which have shown the feasibility of detecting fine debondings in pavements