21 research outputs found

    Air Traffic Management Abbreviation Compendium

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    As in all fields of work, an unmanageable number of abbreviations are used today in aviation for terms, definitions, commands, standards and technical descriptions. This applies in general to the areas of aeronautical communication, navigation and surveillance, cockpit and air traffic control working positions, passenger and cargo transport, and all other areas of flight planning, organization and guidance. In addition, many abbreviations are used more than once or have different meanings in different languages. In order to obtain an overview of the most common abbreviations used in air traffic management, organizations like EUROCONTROL, FAA, DWD and DLR have published lists of abbreviations in the past, which have also been enclosed in this document. In addition, abbreviations from some larger international projects related to aviation have been included to provide users with a directory as complete as possible. This means that the second edition of the Air Traffic Management Abbreviation Compendium includes now around 16,500 abbreviations and acronyms from the field of aviation

    Mitigating Noise in Interferometric Gravitational Wave Detectors

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    Gravitational waves, first predicted by Einstein in 1916, eluded detection for nearly a century. These faint ripples in the fabric of spacetime, with typical strain amplitudes at the Earth on the order of |h| ∼ 10−22, carry secrets of the universe untold by electromagnetic radiation. Following decades of research and development, a network of terrestrial interferometric detectors succeeded in measuring the passing of a gravitational wave (GW150914) for the first time in 2015. Individual detectors within this network are currently said to be operating in a “second-generation” configuration; over the next decade, planned upgrades will take these detectors beyond this into a new generation. This thesis concerns the characterization and reduction of noise in one of these second-generation detectors, Advanced LIGO, as well as efforts underway to improve its sensitivity in the coming years. The first part of this thesis is a detailed overview of gravitational waves, the history of gravitational wave detection, and a reasonably thorough description of the Advanced LIGO detector. Particular attention is paid to a pedagogical motivation of the optical configuration of Advanced LIGO with reference to its forebears. This part ends with an overview of the sources of noise limiting the sensitivity of Advanced LIGO, and an exposition of plans to reduce their influence in the future. The second part describes the development of a laser gyroscope for use in tilt sensing in Advanced LIGO, starting with a motivation of the work based on limitations in the area of seismic noise sensing and cancellation. The third part recounts the design, fabrication, testing, installation and commissioning of an important component of the Advanced LIGO detector: the output mode cleaner (OMC). The fourth part outlines a proposed scheme for reduction of quantum noise in gravitational wave detectors and other experiments. In particular, this scheme allows for the operation of a so-called “optical spring” cavity in such a way as to be largely immune from the deleterious effects of quantum radiation pressure noise. The fifth and final part describes progress towards a direct measurement of thermal noise in thin silicon ribbons, which is pertinent to the design of suspensions in future cryogenic gravitational wave detectors. This thesis has the internal LIGO document number P1900035.</p

    GSI Scientific Report 2011 [GSI Report 2012-1]

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    Smart and high-performance digital-to-analog converters with dynamic-mismatch mapping

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    The trends of advanced communication systems, such as the high data rate in multi-channel base-stations and digital IF conversion in software-defined radios, have caused a continuously increasing demand for high performance interface circuits between the analog and the digital domain. A Digital-to-Analog converter (DAC) is such an interface circuit in the transmitter path. High bandwidth, high linearity and low noise are the main design challenges in high performance DACs. Current-steering is the most suitable architecture to meet these performance requirements. The aim of this thesis is to develop design techniques for high-speed high-performance Nyquist current-steering DACs, especially for the design of DACs with high dynamic performance, e.g. high linearity and low noise. The thesis starts with an introduction to DACs in chapter 2. The function in time/frequency domain, performance specifications, architectures and physical implementations of DACs are brie y discussed. Benchmarks of state-of-the-art published Nyquist DACs are also given. Chapter 3 analyzes performance limitations by various error sources in Nyquist current-steering DACs. The outcome shows that in the frequency range of DC to hundreds of MHz, mismatch errors, i.e. amplitude and timing errors, dominate the DAC linearity. Moreover, as frequencies increase, the effect of timing errors becomes more and more dominant over that of amplitude errors. Two new parameters, i.e. dynamic-INL and dynamic-DNL, are proposed to evaluate the matching of current cells. Compared to the traditional static-INL/DNL, the dynamic-INL/DNL can describe the matching between current cells more accurately and completely. By reducing the dynamic-INL/DNL, the non-linearities caused by all mismatch errors can be reduced. Therefore, both the DAC static and dynamic performance can be improved. The dynamic-INL/DNL are frequency-dependent parameters based on the measurement modulation frequency fm. This fm determines the weight between amplitude and timing errors in the dynamic-INL/DNL. Actually, this gives a freedom to optimize the DAC performance for different applications, e.g. low fm for low frequency applications and high fm for high frequency applications. Chapter 4 summarizes the existing design techniques for intrinsic and smart DACs. Due to technology limitations, it is diffcult to reduce the mismatch errors just by intrinsic DAC design with reasonable chip area and power consumption. Therefore, calibration techniques are required. An intrinsic DAC with calibration is called a smart DAC. Existing analog calibration techniques mainly focus on current source calibration, so that the amplitude error can be reduced. Dynamic element matching is a kind of digital calibration technique. It can reduce the non-linearities caused by all mismatch errors, but at the cost of an increased noise oor. Mapping is another kind of digital calibration technique and will not increase the noise. Mapping, as a highly digitized calibration technique, has many advantages. Since it corrects the error effects in the digital domain, the DAC analog core can be made clean and compact, which reduces the parasitics and the interference generated in the analog part. Traditional mapping is static-mismatch mapping, i.e. mapping only for amplitude errors, which many publications have already addressed on. Several concepts have also been proposed on mapping for timing errors. However, just mapping for amplitude or timing error is not enough to guarantee a good performance. This work focuses on developing mapping techniques which can correct both amplitude and timing errors at the same time. Chapter 5 introduces a novel mapping technique, called dynamic-mismatch mapping (DMM). By modulating current cells as square-wave outputs and measuring the dynamic-mismatch errors as vectors, DMM optimizes the switching sequence of current cells based on dynamic-mismatch error cancelation such that the dynamic-INL can be reduced. After reducing the dynamic-INL, the non-linearities caused by both amplitude and timing errors can be significantly reduced in the whole Nyquist band, which is confirmed by Matlab behavioral-level Monte-Carlo simulations. Compared to traditional static-mismatch mapping (SMM), DMM can reduce the non-linearities caused by both amplitude and timing errors. Compared to dynamic element matching (DEM), DMM does not increase the noise floor. The dynamic-mismatch error has to be accurately measured in order to gain the maximal benefit from DMM. An on-chip dynamic-mismatch error sensor based on a zero-IF receiver is proposed in chapter 6. This sensor is especially designed for low 1/f noise since the signal is directly down-converted to DC. Its signal transfer function and noise analysis are also given and con??rmed by transistor-level simulations. Chapter 7 gives a design example of a 14-bit current-steering DAC in 0.14mum CMOS technology. The DAC can be configured in an intrinsic-DAC mode or a smart-DAC mode. In the intrinsic-DAC mode, the 14-bit 650MS/s intrinsic DAC core achieves a performance of SFDR&gt;65dBc across the whole 325MHz Nyquist band. In the smart-DAC mode, compared to the intrinsic DAC performance, DMM improves the DAC performance in the whole Nyquist band, providing at least 5dB linearity improvement at 200MS/s and without increasing the noise oor. This 14-bit 200MS/s smart DAC with DMM achieves a performance of SFDR&gt;78dBc, IM

    14th International Conference on RF Superconductivity

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    Implémentation, ajustement laser et modélisation des convertisseurs numériques à analogique R2R

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    La conversion numérique à analogique -- Principales caractéristiques des CNA -- Algorithmes et architectures de conversion -- Techniques de linéarisation -- Le CNA R2R inversé -- Un CNA 14 bits ajusté au laser et fabriqué dans une technologie CMOS standard -- Puce -- Montage de test -- Notes et résultats de tests -- Une compensation améliorée pour les interrupteurs des CNA R2R inversés -- Modélisation des CNA R2R

    The ALICE experiment at the CERN LHC

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    ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008

    The CMS experiment at the CERN LHC

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    The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10^(34) cm^(−2) s^(−1) (10^(27) cm^(−2) s^(−1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4π solid angle. Forward sampling calorimeters extend the pseudorapidity coverage to high values (|η| ≤ 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t

    The CMS experiment at the CERN LHC

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    The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10^(34) cm^(−2) s^(−1) (10^(27) cm^(−2) s^(−1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4π solid angle. Forward sampling calorimeters extend the pseudorapidity coverage to high values (|η| ≤ 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t
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