1,616 research outputs found

    Review of Detection and Monitoring Systems for Buried High Pressure Pipelines:Final Report

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    The Netherlands has approximately two million kilometers of underground cables and pipelines. One specific type of buried infrastructure is the distribution network of hazardous material such as gas, oil, and chemicals (‘transportleiding gevaarlijke stoffen’). This network comprises 22.000 kilometers of high-pressure transportation pipelines. Because they are located under the ground, these pipelines are subject to excavation damages. Incidents in them Belgian Gellingen (2004) and German Ludwigshafen (2014) show that consequences of pipeline damages are significant. They can cause fatalities to excavation workers and impact the environment too. In addition, only direct costs for recovery of damages are estimated by the pipeline owner association (VELIN) to range already from several hundreds of thousands to even a few millions of euros. This figure does not yet include the indirect costs. Serious incidents will eventually undermine the public’s acceptance for hazardous pipelines, so it goes without saying that pipeline excavation incidents should, therefore, be avoided. Nowadays, third parties seem to be causing most of the damage to underground pipelines (Capstick, 2007; CONCAWE, 2013; EGIG, 2015; J. M. Muggleton & Rustighi, 2013). Reasons for this, often mentioned by industry, are that utility location information (KLIC-melding) is not always available and, when available, it is not always accurate or too difficult to interpret by excavator operators. It is crucial to detect underground infrastructure in a timely fashion to avoid damages. For this purpose, initiatives are needed to help excavator operators to detect pipelines and monitor groundworks taking place close to pipelines. Such initiatives could focus on the identification and the development of technologies for pipeline strike avoidance. The first step in this direction was this study – which in turn is related to the Safety Deals that are prepared by the association of pipeline owners in the Netherlands (VELIN) and the Dutch Ministry of Infrastructure and the Environment. VELIN and I&M requested the University of Twente to systematically review existing technologies for excavation damage avoidance. Such an overview is not available to the Dutch industry to date. The project team therefore identified and described existing systems for global monitoring and detection of utilities. These systems eventually help detect clashes between excavator equipment and high-pressure transportation pipelines

    Experimental Investigation Of Ultrawideband Wireless Systems: Waveform Generation, Propagation Estimation, And Dispersion Compensation

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    Ultrawideband (UWB) is an emerging technology for the future high-speed wireless communication systems. Although this technology offers several unique advantages like robustness to fading, large channel capacity and strong anti-jamming ability, there are a number of practical challenges which are topics of current research. One key challenge is the increased multipath dispersion which results because of the fine temporal resolution. The received response consists of different components, which have certain delays and attenuations due to the paths they took in their propagation from the transmitter to the receiver. Although such challenges have been investigated to some extent, they have not been fully explored in connection with sophisticated transmit beamforming techniques in realistic multipath environments. The work presented here spans three main aspects of UWB systems including waveform generation, propagation estimation, and dispersion compensation. We assess the accuracy of the measured impulse responses extracted from the spread spectrum channel sounding over a frequency band spanning 2-12 GHz. Based on the measured responses, different transmit beamforming techniques are investigated to achieve high-speed data transmission in rich multipath channels. We extend our work to multiple antenna systems and implement the first experimental test-bed to investigate practical challenges such as imperfect channel estimation or coherency between the multiple transmitters over the full UWB band. Finally, we introduce a new microwave photonic arbitrary waveform generation technique to demonstrate the first optical-wireless transmitter system for both characterizing channel dispersion and generating predistorted waveforms to achieve spatio-temporal focusing through the multipath channels

    Indoor wireless communications and applications

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    Chapter 3 addresses challenges in radio link and system design in indoor scenarios. Given the fact that most human activities take place in indoor environments, the need for supporting ubiquitous indoor data connectivity and location/tracking service becomes even more important than in the previous decades. Specific technical challenges addressed in this section are(i), modelling complex indoor radio channels for effective antenna deployment, (ii), potential of millimeter-wave (mm-wave) radios for supporting higher data rates, and (iii), feasible indoor localisation and tracking techniques, which are summarised in three dedicated sections of this chapter

    Software-only TDOA/RTF positioning for 3G WCDMA wireless network

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    A hybrid location finding technique based oil time difference of arrival (TDOA) with round-trip time (RTT) measurements is proposed for a wideband code division Multiple access (WCDMA) network. In this technique, a mobile station measures timing from at least three base stations using user equipment receive-transmit (UE Rx-Tx) time difference and at least three base stations measure timing from the mobile station using RTT. The timing measurements of mobile and base stations are then combined to solve for both the location of the mobile and the synchronization offset between base stations. A software-only geolocation system based on the above mobile/base stations timing measurements is implemented in Matlab platform and the performance of the system is investigated using large-scale propagation models

    Indoor location based services challenges, requirements and usability of current solutions

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    Indoor Location Based Services (LBS), such as indoor navigation and tracking, still have to deal with both technical and non-technical challenges. For this reason, they have not yet found a prominent position in people’s everyday lives. Reliability and availability of indoor positioning technologies, the availability of up-to-date indoor maps, and privacy concerns associated with location data are some of the biggest challenges to their development. If these challenges were solved, or at least minimized, there would be more penetration into the user market. This paper studies the requirements of LBS applications, through a survey conducted by the authors, identifies the current challenges of indoor LBS, and reviews the available solutions that address the most important challenge, that of providing seamless indoor/outdoor positioning. The paper also looks at the potential of emerging solutions and the technologies that may help to handle this challenge

    Whitepaper on New Localization Methods for 5G Wireless Systems and the Internet-of-Things

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    Collaborative navigation as a solution for PNT applications in GNSS challenged environments: report on field trials of a joint FIG / IAG working group

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    PNT stands for Positioning, Navigation, and Timing. Space-based PNT refers to the capabilities enabled by GNSS, and enhanced by Ground and Space-based Augmentation Systems (GBAS and SBAS), which provide position, velocity, and timing information to an unlimited number of users around the world, allowing every user to operate in the same reference system and timing standard. Such information has become increasingly critical to the security, safety, prosperity, and overall qualityof-life of many citizens. As a result, space-based PNT is now widely recognized as an essential element of the global information infrastructure. This paper discusses the importance of the availability and continuity of PNT information, whose application, scope and significance have exploded in the past 10–15 years. A paradigm shift in the navigation solution has been observed in recent years. It has been manifested by an evolution from traditional single sensor-based solutions, to multiple sensor-based solutions and ultimately to collaborative navigation and layered sensing, using non-traditional sensors and techniques – so called signals of opportunity. A joint working group under the auspices of the International Federation of Surveyors (FIG) and the International Association of Geodesy (IAG), entitled ‘Ubiquitous Positioning Systems’ investigated the use of Collaborative Positioning (CP) through several field trials over the past four years. In this paper, the concept of CP is discussed in detail and selected results of these experiments are presented. It is demonstrated here, that CP is a viable solution if a ‘network’ or ‘neighbourhood’ of users is to be positioned / navigated together, as it increases the accuracy, integrity, availability, and continuity of the PNT information for all users

    Report on Radio Frequency Compatibility Measurements between UWB LDC Devices and Mobile WiMAX (IEEE 802.16e-2005) BWA Systems

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    In 2006 the ECC examined the impact of pulsed Low-Duty Cycle (LDC) UWB signals on the quality of various services (FTP, VoIP, video streaming) provided via a fixed WiMAX (IEEE802.16d) link, and published its findings in ECC Report 94 [1] . The resulting spectrum regulation and standardization stipulate a maximum UWB activity (Ton) of 50 ms per second, with a maximum permissible pulse width of 5 ms. Report 94 showed that for activity factors of 5% there was no measurable impact on any of the victim services if a minimum distance of 4 meters (LOS) between the UWB interferer and the WiMAX terminal was maintained. As fixed WiMAX terminals are typically mounted outdoors in elevated positions the isolation between a WiMAX terminal and LDC UWB devices will in most cases be sufficiently high to avoid interference. Mobile WiMAX (IEEE802.16e-2005) terminals, however, may be operating indoors, in close vicinity to a UWB device. On the other hand, mobile WiMAX was designed to be more robust against fading and interference than fixed WiMAX. The objective of the measurement campaign described in this document was to determine the impact of UWB LDC signals on different types of services provided by a mobile WiMAX (IEEE802.16e-2005, further on referred to as “WiMAX”) victim system, and in particular to examine LDC pulses with a width of more than 5 ms, whilst maintaining an overall activity limit of 5%, equalling 50 ms per second.JRC.DG.G.6-Security technology assessmen
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