452 research outputs found

    A New Approach to Tagging Data in the Astronomical Literature

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    Data Tags are strings used in journals to indicate the origin of the archival data and to enable the reader to recover the data. The NASA/IPAC Infrared Science Archive (IRSA) has recently introduced a new approach to production of data tags and recovery of data from them. Many of the data access services at the IRSA return filtered data sets (such as subsets of source catalogs) and dynamically created products (such as image cutouts); these dynamically created products are not saved permanently at the archive. Rather than tag the data sets from which the query result sets are drawn, the archive tags the query that generates the results. A single tag can, then, encode a complex dynamic data set and simplifies the embedding of tags in manuscripts and journals. By logging user queries and all the parameters for those query as Data Tags, IRSA can re-create the query and rerun the IRSA service using the same search parameters used when the Data Tag was created. At the same time, the logs give a simple count of the actual numbers of queries made to the archive, a powerful metric of archive usage unobtainable from the Apache web server logs. Currently, IRSA creates tags for queries to more than 20 data sets, including the Infrared Astronomical Satellite (IRAS), Cosmic Evolution Survey (COSMOS) and Spitzer Space Telescope Legacy Data Sets. These tags are returned by the spatial query engine, Atlas. IRSA plans to create tags for queries to the rest of its services in late Spring 2007. The archive provides a simple web interface which recovers a data set that corresponds to the input data tag. Archived data sets may evolve in time due to improved calibrations or augmentations to the data set. IRSA’s query based approach guarantees that users always receive the best available data sets

    Sustaining the Montage Image Mosaic Engine Since 2002

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    This paper describes how we have sustained the Montage image mosaic engine (http://montage.ipac.caltech.edu) first released in 2002, to support the ever-growing scale and complexity of modern data sets. The key to its longevity has been its design as a toolkit written in ANSI-C, with each tool performing one distinct task, for easy integration into scripts, pipelines and workflows. The same code base now supports Windows, JavaScript and Python by taking advantage of recent advances in compilers. The design has led to applicability of Montage far beyond what was anticipated when Montage was first built, such as supporting observation planning for the JWST. Moreover, Montage is highly scalable and is in wide use within the IT community to develop advanced, fault-tolerant cyber-infrastructure, such as job schedulers for grids, workflow orchestration, and restructuring techniques for processing complex workflows and pipelines.Comment: 12 pages, 8 figures. Software and Cyberinfrastructure for Astronomy V (Conference 10707), SPIE SPIE Astronomical Telescopes + Instrumentation, Austin TX. June 10-15, 201

    ROME (Request Object Management Environment)

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    Most current astronomical archive services are based on an HTML/ CGI architecture where users submit HTML forms via a browser and CGI programs operating under a web server process the requests. Most services return an HTML result page with URL links to the result files or, for longer jobs, return a message indicating that email will be sent when the job is done. This paradigm has a few serious shortcomings. First, it is all too common for something to go wrong and for the user to never hear about the job again. Second, for long and complicated jobs there is often important intermediate information that would allow the user to adjust the processing. Finally, unless some sort of custom queueing mechanism is used, background jobs are started immediately upon receiving the CGI request. When there are many such requests the server machine can easily be overloaded and either slow to a crawl or crash. Request Object Management Environment (ROME) is a collection of middleware components being developed under the National Virtual Observatory Project to provide mechanism for managing long jobs such as computationally intensive statistical analysis requests or the generation of large scale mosaic images. Written as EJB objects within the open-source JBoss applications server, ROME receives processing requests via a servelet interface, stores them in a DBMS using JDBC, distributes the processing (via queuing mechanisms) across multiple machines and environments (including Grid resources), manages realtime messages from the processing modules, and ensures proper user notification. The request processing modules are identical in structure to standard CGIprograms – though they can optionally implement status messaging – and can be written in any language. ROME will persist these jobs across failures of processing modules, network outages, and even downtime of ROME and the DBMS, restarting them as necessary

    Connecting the time domain community with the Virtual Astronomical Observatory

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    The time domain has been identified as one of the most important areas of astronomical research for the next decade. The Virtual Observatory is in the vanguard with dedicated tools and services that enable and facilitate the discovery, dissemination and analysis of time domain data. These range in scope from rapid notifications of time-critical astronomical transients to annotating long-term variables with the latest modeling results. In this paper, we will review the prior art in these areas and focus on the capabilities that the VAO is bringing to bear in support of time domain science. In particular, we will focus on the issues involved with the heterogeneous collections of (ancillary) data associated with astronomical transients, and the time series characterization and classification tools required by the next generation of sky surveys, such as LSST and SKA.Comment: Submitted to Proceedings of SPIE Observatory Operations: Strategies, Processes and Systems IV, Amsterdam, 2012 July 2-

    Fabrication Infrastructure to Enable Efficient Exploration and Utilization of Space

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    Unlike past one-at-a-time mission approaches, system-of-systems infrastructures will be needed to enable ambitious scenarios for sustainable future space exploration and utilization. Fabrication infrastructure will be needed to support habitat structure development, tools and mechanical part fabrication, as well as repair and replacement of ground support and space mission hardware such as life support items, vehicle components and crew systems. The fabrication infrastructure will need the In Situ Fabrication and Repair (ISFR) element, which is working in conjunction with the In Situ Resources Utilization (ISRU) element, to live off the land. The ISFR Element supports the entire life cycle of Exploration by: reducing downtime due to failed components; decreasing risk to crew by recovering quickly from degraded operation of equipment; improving system functionality with advanced geometry capabilities; and enhancing mission safety by reducing assembly part counts of original designs where possible. This paper addresses the fabrication infrastructures that support efficient, affordable, reliable infrastructures for both space exploration systems and logistics; these infrastructures allow sustained, affordable and highly effective operations on the Moon, Mars and beyond

    Montage: An Astronomical Image Mosaic Service for the NVO

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    Montage is a software system for generating astronomical image mosaics according to user-specified size, rotation, WCS-compliant projection and coordinate system, with background modeling and rectification capabilities. Its architecture has been described in the proceedings of ADASS XII and XIII (Berriman et al. 2003, 2004). It has been designed as a toolkit, with independent modules for image reprojection, background rectification and co-addition, and will run on workstations, clusters and grids. The primary limitation of Montage thus far has been in the projection algorithm. It uses a spherical trigonometry approach that is general at the expense of speed. The reprojection algorithm has now been made 30 times faster for commonly used tangent plane to tangent plane reprojections that cover up to several square degrees, through modification of a custom algorithm first derived for the Spitzer Space Telescope. This focus session will describe this algorithm, demonstrate the generation of mosaics in real time, and describe applications of the software. In particular, we will highlight one case study which shows how Montage is supporting the generation of science-grade mosaics of images measured with the Infrared Array Camera aboard the Spitzer Space Telescope
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