11,458 research outputs found
The STAR MAPS-based PiXeL detector
The PiXeL detector (PXL) for the Heavy Flavor Tracker (HFT) of the STAR
experiment at RHIC is the first application of the state-of-the-art thin
Monolithic Active Pixel Sensors (MAPS) technology in a collider environment.
Custom built pixel sensors, their readout electronics and the detector
mechanical structure are described in detail. Selected detector design aspects
and production steps are presented. The detector operations during the three
years of data taking (2014-2016) and the overall performance exceeding the
design specifications are discussed in the conclusive sections of this paper
Current optical technologies for wireless access
The objective of this paper is to describe recent activities and investigations on free-space optics (FSO) or optical wireless and the excellent results achieved within SatNEx an EU-framework 6th programme and IC 0802 a COST action. In a first part, the FSO technology is briefly discussed. In a second part, we mention some performance evaluation criterions for the FSO. In third part, we briefly discuss some optical signal propagation experiments through the atmosphere by mentioning network architectures for FSO and then discuss the recent investigations in airborne and satellite application experiments for FSO. In part four, we mention some recent investigation results on modelling the FSO channel under fog conditions and atmospheric turbulence. Additionally, some recent major performance improvement results obtained by employing hybrid systems and using some specific modulation and coding schemes are presented
Preliminary candidate advanced avionics system for general aviation
An integrated avionics system design was carried out to the level which indicates subsystem function, and the methods of overall system integration. Sufficient detail was included to allow identification of possible system component technologies, and to perform reliability, modularity, maintainability, cost, and risk analysis upon the system design. Retrofit to older aircraft, availability of this system to the single engine two place aircraft, was considered
Wireless communication, identification and sensing technologies enabling integrated logistics: a study in the harbor environment
In the last decade, integrated logistics has become an important challenge in
the development of wireless communication, identification and sensing
technology, due to the growing complexity of logistics processes and the
increasing demand for adapting systems to new requirements. The advancement of
wireless technology provides a wide range of options for the maritime container
terminals. Electronic devices employed in container terminals reduce the manual
effort, facilitating timely information flow and enhancing control and quality
of service and decision made. In this paper, we examine the technology that can
be used to support integration in harbor's logistics. In the literature, most
systems have been developed to address specific needs of particular harbors,
but a systematic study is missing. The purpose is to provide an overview to the
reader about which technology of integrated logistics can be implemented and
what remains to be addressed in the future
The Fluorescence Detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a hybrid detector for ultra-high energy
cosmic rays. It combines a surface array to measure secondary particles at
ground level together with a fluorescence detector to measure the development
of air showers in the atmosphere above the array. The fluorescence detector
comprises 24 large telescopes specialized for measuring the nitrogen
fluorescence caused by charged particles of cosmic ray air showers. In this
paper we describe the components of the fluorescence detector including its
optical system, the design of the camera, the electronics, and the systems for
relative and absolute calibration. We also discuss the operation and the
monitoring of the detector. Finally, we evaluate the detector performance and
precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics
Research Section
NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 36)
Abstracts are provided for 63 patents and patent applications entered into the NASA scientific and technical information systems during the period July 1989 through December 1989. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application
HATSouth: a global network of fully automated identical wide-field telescopes
HATSouth is the world's first network of automated and homogeneous telescopes
that is capable of year-round 24-hour monitoring of positions over an entire
hemisphere of the sky. The primary scientific goal of the network is to
discover and characterize a large number of transiting extrasolar planets,
reaching out to long periods and down to small planetary radii. HATSouth
achieves this by monitoring extended areas on the sky, deriving high precision
light curves for a large number of stars, searching for the signature of
planetary transits, and confirming planetary candidates with larger telescopes.
HATSouth employs 6 telescope units spread over 3 locations with large longitude
separation in the southern hemisphere (Las Campanas Observatory, Chile; HESS
site, Namibia; Siding Spring Observatory, Australia). Each of the HATSouth
units holds four 0.18m diameter f/2.8 focal ratio telescope tubes on a common
mount producing an 8.2x8.2 arcdeg field, imaged using four 4Kx4K CCD cameras
and Sloan r filters, to give a pixel scale of 3.7 arcsec/pixel. The HATSouth
network is capable of continuously monitoring 128 square arc-degrees. We
present the technical details of the network, summarize operations, and present
weather statistics for the 3 sites. On average each of the 6 HATSouth units has
conducted observations on ~500 nights over a 2-year time period, yielding a
total of more than 1million science frames at 4 minute integration time, and
observing ~10.65 hours per day on average. We describe the scheme of our data
transfer and reduction from raw pixel images to trend-filtered light curves and
transiting planet candidates. Photometric precision reaches ~6 mmag at 4-minute
cadence for the brightest non-saturated stars at r~10.5. We present detailed
transit recovery simulations to determine the expected yield of transiting
planets from HATSouth. (abridged)Comment: 25 pages, 11 figures, 1 table, submitted to PAS
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