检索结果-内蒙古大学图书馆

conference on Ground-based telescopes

作者： Booth, JA Adams, MT Barker, ES Bash, FN Fowler, JR Good, JM Hill, GJ Kelton, PW Lambert, DL MacQueen, PJ Palunas, P Ramsey, LW Wesley, GL Univ Texas McDonald Observ Austin TX 78712 USA

ISBN: (纸本)0819454214

The Hobby-Eberly telescope (HET) is a fixed-elevation, 9.2-m telescope with a spherical primary mirror and a tracker at prime focus to follow astronomical objects. The telescope was constructed for $13.9M over the period 1994-1997. A series of extensive engineering upgrades and corrective actions have been completed recently, resulting in significantly improved delivered image quality and increased operational efficiency. The telescope's Spherical Aberration Corrector (SAC) optics were recoated with a highly reflective and durable broadband coating at Lawrence Livermore National Laboratory. The software mount model that maintains optical alignment of the SAC with the 11-m primary mirror array was recalibrated and improved. The acquisition and guiding optics for both the High Resolution Spectrograph (HRS) and the Low Resolution Spectrograph (LRS) were reworked and improved, allowing for better focus and SAC alignment monitoring and control. Recoating of the primary mirror segment array was begun. telescope images of 0.82 arcseconds have been recorded for sustained periods in preliminary testing following the engineering upgrade, an improvement of 50% over previous best performance. Additional engineering upgrades are scheduled to consolidate these performance gains and to continue improving delivered image quality, throughput, and telescope operational efficiency. The HET is now capable of the science performance for which it was designed.

关键词： Hobby-Eberly telescope HET dome seeing dome ventilation optical testing mirror alignment aluminizing SAMS edge sensors DIMM

来源：评论

学校读者我要写书评

暂无评论

ALMA correlator computer systems

ALMA correlator computer systems

引用

conference on advanced software, control and Communication Systems for Astronomy

作者： Pisano, J Amestica, R Perez, J Natl Radio Astron Observ Charlottesville VA 22901 USA

ISBN: (纸本)0819454281

We present a design for the computer systems which control, configure, and monitor the Atacama Large Millimeter Array (ALMA) correlator and process its output. Two distinct computer systems implement this functionality: a rack- mounted PC controls and monitors the correlator, and a cluster of 17 PCs process the correlator output into raw spectral results. The correlator computer systems interface to other ALMA computers via gigabit Ethernet networks utilizing CORBA and raw socket connections. ALMA Common software provides the software infrastructure for this distributed computer environment. The control computer interfaces to the correlator via multiple CAN busses and the data processing computer cluster interfaces to the correlator via sixteen dedicated high speed data ports. An independent array-wide hardware timing bus connects to the computer systems and the correlator hardware ensuring synchronous behavior and imposing hard deadlines on the control and data processor computers. An aggregate correlator output of 1 gigabyte per second with 16 millisecond periods and computational data rates of approximately 1 billion floating point operations per second define other hard deadlines for the data processing computer cluster.

关键词： ALMA correlator computer software real-time

来源：评论

学校读者我要写书评

暂无评论

The ALMA software architecture

The ALMA software architecture

引用

conference on advanced software, control and Communication Systems for Astronomy

作者： Schwarz, J Farris, A Sommer, H European So Observ D-8046 Garching Germany

ISBN: (纸本)0819454281

The software for the Atacama Large Millimeter Array (ALMA) is being developed by many institutes on two continents. The software itself will function in a distributed environment, from the 0.5-14 km baselines that separate antennas to the larger distances that separate the array site at the Llano de Chajnantor in Chile from the operations and user support facilities in Chile, North America and Europe. Distributed development demands 1) interfaces that allow separated groups to work with minimal dependence on their counterparts at other locations;and 2) a common architecture to minimize duplication and ensure that developers can always perform similar tasks in a similar way. The Container/Component model provides a blueprint for the separation of functional from technical concerns: application developers concentrate on implementing functionality in Components, which depend on Containers to provide them with services such as access to remote resources, transparent serialization of entity objects to XML, logging, error-handling and security. Early system integrations have verified that this architecture is sound and that developers can successfully exploit its features. The Containers and their services are provided by a system-oriented development team as part of the ALMA Common software (ACS), middleware that is based on CORBA.

关键词： software architecture ALMA radio astronomy

来源：评论

学校读者我要写书评

暂无评论

control software for OSIRIS: an infrared integral-field spectrograph for the Keck adaptive optics system

Control software for OSIRIS: an infrared integral-field spec...

引用

conference on advanced software, control and Communication Systems for Astronomy

作者： Weiss, JL Barczys, M Larkin, JE Honey, A McElwain, MW Gasaway, TM Krabbe, A Univ Calif Los Angeles Dept Phys & Astron Los Angeles CA 90095 USA

ISBN: (纸本)0819454281

OSIRIS is an infrared integral-field spectrograph built for the Keck AO system. Integral-field spectrographs produce very complicated raw data products, and OSIRIS is no exception. OSIRIS produces frames that contain up to 4096 interleaved spectra. In addition to the IFU capabilities of OSIRIS, the instrument is equipped with a parallel-field imager to monitor current AO conditions by imaging, an off-axis star and evaluating its PSF. The design of the OSIRIS software was driven by the complexity of the instrument, switching the focus from simply controlling the instrument components to targeting the acquisition of usable scientific data. OSIRIS software integrates the planning, execution, and reduction of observations. An innovation in the OSIRIS control software is the formulation of observations into 'datasets' rather than individual frames. Datasets are functional groups of frames organized by the needs and capabilities of the data reduction software (DRS). A typical OSIRIS dataset consists of dithered spectral observations, coupled with the associated imaging data from the parallel-field AO PSF imager. A Java-based planning tool enables 'sequences' of datasets to be planned and saved both prior to and during observing sessions. An execution client interprets these XML-based files, configures the hardware servers for both OSIRIS and AO, and executes the observations. The DRS, working on one dataset of raw data at a time, produces science-quality data that is ready for analysis. This methodology should lead to superior observational efficiency, decreased likelihood of observer error, minimized reduction time, and therefore, faster scientific discovery.

关键词： control software observation planning astronomical instrumentation integral-field spectroscopy data acquisition

来源：评论

学校读者我要写书评

暂无评论

Subaru telescope: Current performances and future upgrade plans

Subaru Telescope: Current performances and future upgrade pl...

引用

conference on Ground-based telescopes

作者： Usuda, T Takato, N Kanzawa, T Miyashita, A Uraguchi, F Kurakami, T Kosugi, G Hayashi, SS Akiyama, M Itoh, N Negishi, S Sugahara, S Tanaka, W Natl Astron Observ Subaru Telescope Hilo HI 96720 USA

ISBN: (纸本)0819454214

The Subaru telescope has been stably operated with high image quality since common use began in December 2000. We have updated the following items in order to achieve further improvement of observation efficiency, image quality, and tracking. 1. High reflectivity of mirrors. The reflectivity of the primary mirror has been maintained, yielding 84% at 670 nm by regular CO2 cleaning (every two to three weeks). We successfully carried out the silver coating of the Infrared secondary mirror in April 2003 without over-coating. The reflectivity has been maintained at greater 98% at 1,300 mn. 2. Image Quality. Subaru telescope delivers exceptional image quality - a median image size of 0.6 arc-second FWHM in the R-band as taken by Auto-Guider Cameras at all four foci;Prime, Cassegrain, and two Nasmyth. We optimized parameters of the servo control system of the Elevation servo, reducing the amplitude of 3-8 Hz vibration mode of the telescope and improving image quality when using the Adaptive Optics (AO) system. 3. Acquisition Guiding. Dithering time was shortened by updating the control software. The slit viewer camera for HDS and the fiber bundle for FMOS are available for acquisition guiding in addition to Auto-Guider Cameras. 4. New instruments. We are developing a new prime focus unit for FMOS and will start functional tests in 2005. Moreover, we have started to prepare new interfaces and facilities for FMOS and the new 188 element AO natural/laser guide star system. The focus switching time will be shortened by updating the hardware of the IR and Cassegrain Optical secondary mirrors from September 2004, reducing it to 10 minutes to switch the focus between Cassegrain and Nasmyth foci.

关键词： Subaru telescope ground based large telescope astronomy

来源：评论

学校读者我要写书评

暂无评论

Observation planning tools for the ESO VLT interferometer

Observation planning tools for the ESO VLT interferometer

引用

conference on Optimizing Scientific Return for Astronomy through Information Technologies

作者： McKay, DJ Ballester, P Vinther, J European So Observ D-85748 Garching Germany

ISBN: (纸本)0819454257

Now that the Very Large telescope Interferometer (VLTI) is producing regular scientific observations, the field of optical interferometry has moved from being a specialist niche area into mainstream astronomy. Making such instruments available to the general community involves difficult challenges in modelling, presentation and automation. The planning of each interferometric observation requires calibrator source selection, visibility prediction, signal-to-noise estimation and exposure time calculation. These planning tools require detailed physical models simulating the complete telescope system - including the observed source, atmosphere, array configuration, optics, detector and data processing. Only then can these software utilities provide accurate predictions about instrument performance, robust noise estimation and reliable metrics indicating the anticipated success of an observation. The information must be presented in a clear, intelligible manner, sufficiently abstract to hide the details of telescope technicalities, but still giving the user a degree of control over the system. The Data Flow System group(1) has addressed the needs of the VLTI and, in doing so, has gained some new insights into the planning of observations, and the modelling and simulation of interferometer performance. This paper reports these new techniques, as well as the successes of the Data Flow System group in this area and a summary of what is now offered as standard to VLTI observers.

关键词： Very Large telescope Interferometer observation planning tools modelling

来源：评论

学校读者我要写书评

暂无评论

TWiki as a platform for collaborative software development management

TWiki as a platform for collaborative software development m...

引用

conference on advanced software, control and Communication Systems for Astronomy

作者： Radziwill, NM Shelton, AL Natl Radio Astron Observ Green Bank WV 24944 USA

ISBN: (纸本)0819454281

The software development process in Green Bank is managed in six-week development cycles, where two cycles fall within one quarter. Each cycle, a Plan of Record is devised which outlines the team's commitments, deliverables, technical leads and scientific sponsors. To be productive and efficient, the team must not only be able to track its progress towards meeting commitments, but also to communicate and circulate the information that will help it meet its goals effectively. In the early summer of 2003, the software Development Division installed a wiki web site using the TWiki product to improve the effectiveness of the team. Wiki sites contain web pages that are maintainable using a web interface by anyone who becomes a registered user of the site. Because the site naturally supports group involvement, the Plan of Record on the wiki now serves as the central dashboard for project tracking each development cycle. As an example of how the wild improves productivity, software documentation is now tracked as evidence of the software deliverable. Written status reports are thus not required when the Plan of Record and associated wiki pages are kept up to date. The wiki approach has been quite successful in Green Bank for document management as well as software development management, and has rapidly extended beyond the bounds of the software development group for information management.

关键词： software development software engineering project management wiki document management

来源：评论

学校读者我要写书评

暂无评论

VisioRock, an integrated vision technology for advanced control of comminution circuits

引用

MINERALS ENGINEERING 2004年第11-12期17卷 1227-1235页

作者： Guyot, O Monredon, T LaRosa, D Broussaud, A Metso Minerals Cisa F-45060 Orleans 2 France Metso Minerals Proc Technol Asia Pacific Brisbane Qld Australia

Over the last few years, a number of vision or optical systems became commercially available to determine particle size distributions of ore or other material on a conveyor belt, or in some cases at the discharge of a truck or even in a pile in some cases. Most such systems were designed as standalone measurement devices, which generate information for the operators or for an independent control system. The VisioRock system is innovative both from the hardware and software point of view. It is based on the USB technology although it can use either analog or industrial USB cameras-and the software is integrated within the vision module of the OCS(C) advanced control software. It is possible to install VisioRock cameras at many different locations in a comminution circuit, which interact with the control system and help to increase plant performance. The paper describes the VisioRock technology and some of the possibilities which result from its integration with OCS(C). For instance, in addition to measuring the particle size distribution of solids, VisioRock can determine texture and color separately for each size class, discriminate between ore types and size distribution for different type of particles, and ability to seamlessly combine image analysis algorithms with other artificial intelligence tools such as expert systems, fuzzy logic, neural networks or phenomenological process models. (C) 2004 Elsevier Ltd. All rights reserved.

关键词： particle size process instrumentation grinding crushing process control

来源：评论

学校读者我要写书评

暂无评论

ACS Sampling System: design, implementation and performance evaluation

ACS Sampling System: design, implementation and performance ...

引用

conference on advanced software, control and Communication Systems for Astronomy

作者： Di Marcantonio, P Cirami, R Chiozzi, G Osserv Astron Trieste INAF I-34131 Trieste Italy

ISBN: (纸本)0819454281

By means of ACS (ALMA Common software) framework we designed and implemented a sampling system which allows sampling of every Characteristic Component Property with a specific, user-defined, sustained frequency limited only by the hardware. Collected data are sent to various clients (one or more Java plotting widgets, a dedicated GUI or a COTS application) using the ACS/CORBA Notification Channel. The data transport is optimized: samples are cached locally and sent in packets with a lower and user-defined frequency to keep network load under control. Simultaneous sampling of the Properties of different Components is also possible. Together with the design and implementation issues we present the performance of the sampling system evaluated on two different platforms: on a VME based system using VxWorks RTOS (currently adopted by ALMA) and on a PC/104+ embedded platform using Red Hat 9 Linux operating system. The PC/104+ solution offers, as an alternative, a low cost PC compatible hardware environment with free and open operating system.

关键词： object-oriented programming software patterns real-time operating systems CORBA

来源：评论

学校读者我要写书评

暂无评论

James Webb Space telescope wavefront sensing and control algorithms

James Webb Space Telescope wavefront sensing and control alg...

引用

conference on Optical, Infrared, and Millimeter Space telescopes

作者： Acton, DS Atcheson, P Cermak, M Kingsbury, L Shi, F Redding, DC Ball Aerospace & Technologies Corp. (United States) Jet Propulsion Lab. (United States)

ISBN: (纸本)0819454192

The Northrup-Grummann/Ball/Kodak team is building the James Webb Space telescope (JWST), scheduled for launch in 2011. Part of Ball's responsibility is to develop the wavefront sensing and control (WFS&C) algorithms and software that will be used to provide the level of imaging performance needed to support the mission's science objectives. Wavefront sensing on JWST differs from that performed on many ground-based telescopes in that it is conducted entirely within the focal plane of it's chief science camera, the Near Infrared Camera (NIRCam). In a sense, the complexity of a conventional wavefront sensor is eliminated, in favor of rather complex image processing performed on the ground, to extract the wavefront information. This paper will describe the algorithms being developed for JWST. Specifically, we will describe algorithms for the coarse alignment of the primary mirror segments and the secondary mirror, the coarse phasing of the primary mirror segments, and the fine phasing of the entire telescope. We will also present algorithms for monitoring the wavefront quality throughout the JWST mission.

关键词： JWST testbeds wavefront sensing and control

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：