ADASS XII Conference

Enabling Technologies

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O6.1 The Design of the MicroObservatory Network of Educational Telescopes (Invited)

Philip M. Sadler (SAO)

Many students have a deep interest in astronomy, but a limited opportunity to use telescopes to explore the heavens. The MicroObservatory Network of automated telescopes is designed to provide access to classroom teachers who wish their students to conduct projects over the World-Wide Web. The intuitive interface makes it easy for even 10-year-olds to take pictures. Our telescopes can be remotely pointed and focused; filters, field of view, and exposure times can be changed easily. Images are archived at the website, along with sample challenges, and a user bulletin board, all of which encourage collaboration among schools. Wide geographic separation of instruments provides for access to distant night skies during local daytime. Operational since 1995, we have learned much about remote troubleshooting, designing for unattended use, and for acquiring the kinds of images that students desire. This network can be scaled up from its present capability of 240,000 images each year to provide telescope access for all U.S. students with an interest in astronomy. Our WWW address is: http://mo-www.harvard.edu/MicroObservatory/

O6.2 Mirage: A Tool for Interactive Pattern Recognition from Multimedia Data

Tin Kam Ho (Bell Laboratories)

Many data mining queries in astronomy involve an identification of objects that are similar or discernible in different aspects such as spectral shapes and features, light curves, morphology, positional proximity, or other derived attributes. Analyses need to go beyond conventional clustering algorithms that stop at computing a single proximity structure according to a specific criterion. We describe Mirage, a software tool designed for interactive exploration of the correlation of multiple partitional or hierarchical cluster structures arising in different contexts. The tool shows projected images of point classes and traversals of proximity structures in one, two, or higher dimensional subspaces, in linked views of tables, histograms, scatter plots, parallel coordinates, or over an image background. It also provides facilities for arbitrary plot configuration, manual or automatic classification, and intuitive graphical querying. We show applications of Mirage to find robust designs of optical devices, verify the consistence of DLS catalogs, and examine spectral classes from IRAS LRS.

O6.3 Montage: An On-Demand Image Mosaic Service for the NVO

G. B. Berriman, D. Curkendall, J. Good, J. Jacob, D. S. Katz, T. Prince, R. Williams (JPL, CalTech)

Montage will deliver a generalized toolkit for generating on-demand, science-grade custom astronomical image mosaics. "Science-grade" in this context requires that terrestrial and instrumental features are removed from images in a way that can be described quantitatively. "Custom" refers to user-specified parameters of projection, coordinates, size, rotation and spatial sampling, and whether the drizzle algorithm should be invoked.

The greatest value of Montage will be its ability to analyze images at multiple wavelengths, by delivering them on a common projection, coordinate system and spatial sampling and thereby allowing analysis as if they were part of the same multi-wavelength image. Montage will be deployed as a compute - intensive service through existing portals. It will be integrated into the emerging NVO architecture, and run operationally on the Teragrid, where it will process the 2MASS, DPOSS and SDSS SDSS image data sets. The software will also be portable and publicly available.

O6.4 Architecture for All-Sky Browsing of Astronomical Datasets

Joseph C. Jacob, Gary Block, David W. Curkendall (Jet Propulsion Laboratory, California Institute of Technology)

A new architecture for all-sky browsing of astronomical datasets, has been designed and implemented in the form of a graphical front-end to the yourSky custom mosaicking engine. With yourSky, any part of the sky can be retrieved as a single FITS image with user-specified parameters such as coordinate system, projection, resolution and data type [1]. The simple HTML form interface to yourSky has been supplemented with a graphical interface that allows: (i) All-sky, web-based pan and zoom; (ii) Interactive, multi-spectral viewing; (iii) Symbol overlays from object catalogs; (iv) Invocation of the yourSky mosaicking engine once a desired view has been selected; (v) Image pixel to sky coordinate conversions; and (vi) User control over display view size. The image viewed by the user at each instant is rendered from a collection of overlapping image plates with limited size for each zoom level. These plates are constructed in a Tangent Plane projection with tangent points selected at Hierarchical Triangular Mesh [2] vertices. The plate sizes are selected to limit the maximum distortion from image projection while providing sufficient overlap between neighboring plates that the sub-image in the view window is wholly contained within a single plate. This results in astrometric accuracy, rapid response time, and efficient data storage. Although the current implementation is interoperable with the yourSky mosaic engine, we believe this architecture should be applicable for front ends to other space science applications and, with little modification, to planetary science applications as well.

References:

[1] J.C. Jacob, R. Brunner, D.W. Curkendall, S.G. Djorgovski, J.C. Good, L. Husman, G. Kremenek and A. Mahabal, "yourSky: Rapid Desktop Access to Custom Astronomical Image Mosaics", to appear in Proceedings of SPIE Astronomical Telescopes and Instrumentation: Virtual Observatories, Waikoloa, HI, Aug., 2002.

[2] P.Z. Kunszt, A.S. Szalay, I. Csabai and A.R. Thakar, "The Indexing of the SDSS Science Archive", Proceedings of ADASS IX, Kona, HI, Oct., 1999.

O6.5 Scoping the UK's Virtual Observatory: AstroGrid's Key Science Drivers and Impact on System Design

Nicholas A Walton (Institute of Astronomy, Cambridge, UK) Andrew Lawrence (Institute for Astronomy, Edinburgh, UK) Tony Linde (Dept. Physics & Astronomy, Leicester, UK)

AstroGrid (see http://www.astrogrid.org), a UK eScience project with collaborating groups drawn from the major UK data archive centres, is creating the UK's first virtual observatory. AstroGrid is aiming to support a broad spectrum of astronomical activity, with an initial emphasis on meeting the needs expressed by the UK community. AstroGrid is aiming to balance the scientific requirements of a wide community which spans the Astronomy, Solar and STP areas.

This paper discusses how the AstroGrid project has captured a well scoped set of key science drivers. These represent a number of currently topical scientific areas where access to capabilities promised by a virtual observatory will make a significant impact on the researchers abilities to progress in these areas. At the same time, the tools and facilities developed to support these drivers will be employable in addressing a wider range of astronomical science problems. The drivers cover aspects of astronomy ranging from facilitating access to large scale survey data sets to speed the discovery of galaxy clusters, through understanding the onset of solar magnetic storms via the analysis of multi-sourced STP data sets.

This paper further describes the process by which the AstroGrid architecture has been formulated. Note is made of the interactive mechanisms provided by the project, linked from http://www.astrogrid.org. In particular the AstroGrid Wiki at http://wiki.astrogrid.org is highlighted as an excellent medium with which to capture user requirements and to disseminate back project developments via, for instance, meeting notes, architecture and other discussions.

The paper closes by noting how the science drivers have been used to determine the system design required to deliver the capabilities that AstroGrid will provide to its community by the end of its three year project lifetime.