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The U.S. Virtual Astronomical Observatory (VAO; http://www.us-vao.org/) has been in operation since May 2010. Its goal is to enable new science through efficient integration of distributed multi-wavelength data. This paper describes the management and organization of the VAO, and emphasizes the techniques used to ensure efficiency in a distributed organization. Management methods include using an annual program plan as the basis for establishing contracts with member organizations, regular communication, and monitoring of processes., Comment: 9 pages, 3 figures. SPIE Conference 8449: Modeling, Systems Engineering, and Project Management for Astronomy V

Broad support for Virtual Observatory (VO) standards by astronomical archives is critical for the success of the VO as a research platform. Indeed, a number of effective data discovery, visualization, and integration tools have been created which rely on this broad support. Thus, to an archive, the motivation for supporting VO standards is strong. However, we are now seeing a growing trend among archive developers towards leveraging VO standards and technologies not just to provide interoperability with the VO, but also to support an archive's internal needs and the needs of the archive's primary user base. We examine the motivation for choosing VO technologies for implementing an archive's functionality and list several current examples, including from the Hubble Legacy Archive, NASA HEASARC, NOAO, and NRAO. We will also speculate on the effect that VO will have on some of the ambitious observatory projects planned for the near future.

Building an automated classifier for high-energy sources provides an opportunity to prototype approaches to building the Virtual Observatory with a substantial immediate scientific return. The ClassX collaboration is combining existing data resources with trainable classifiers to build a tool that classifies lists of objects presented to it. In our first year the collaboration has concentrated on developing pipeline software that finds and combines information of interest and in exploring the issues that will be needed for successful classification. ClassX must deal with many key VO issues: automating access to remote data resources, combining heterogeneous data and dealing with large data volumes. While the VO must attempt to deal with these problems in a generic way, the clear science goals of ClassX allow us to act as a pathfinder exploring particular approaches to addressing these issues.

The U.S. National Science Foundation is sponsoring the development of the infrastructure for the National Virtual Observatory via its Information Technology Research Program. This initiative combines expertise from astronomical observatories, data archive centers, university astronomy departments, and computer science and information technology groups at seventeen different organizations. This paper describes the nature of the project, our approach to managing and coordinating work across such a large collaboration, and the progress made thus far in the initial development activities (metadata standards, systems architecture, and science requirements definition).

The goal of the virtual observatory is to provide seamless, efficient access to astronomical data archives, catalogs, bibliographic services, and computational resources worldwide. This goal can be realized only through the development of a sophisticated information technology infrastructure. The infrastructure must accommodate the integration of diverse data types from potentially thousands of sites and services, capitalizing on emerging computational grid technologies for resource allocation and management. This paper describes the major IT challenges facing the virtual observatory and suggests a middleware architecture capable of supporting its scientific objectives.

The Hubble Data Archive at the Space Telescope Science Institute contains over 4.3 TB of data, primarily for the Hubble Space Telescope, but also from complementary space- based and ground-based facilities. We are in the process of upgrading and generalizing many of the HDA's component system, developing tools to provide more integrated access to the HDA holdings, and working with other major data providing organizations to implement global data location services for astronomy and other space science disciplines. This paper describes the key elements of our archiving and data distribution systems, including a planned transition to DVD media, data compression, data segregation, on-the-fly calibration, an engineering data warehouse, and distributed search and retrieval facilities.

The Hubble Space Telescope image quality is degraded significantly as a result of the spherical aberration in the primary mirror. Although the forthcoming HST servicing mission will deploy corrective optics systems and a second-generation camera with built-in correctors, the current and archival images for the past three years require the use of restoration techniques in order to achieve the full scientific potential of the HST mission. In addition, we expect that the restoration techniques now being developed will continue to be utilized on post- servicing mission imagery in order to remove the remaining diffraction features and optimize dynamic range. A variety of well-known image restoration techniques, such as Wiener filters, Richardson-Lucy, Jansson-van Cittert, CLEAN, and maximum entropy, have been applied to HST imaging with reasonable success. However, all techniques have been hampered by incomplete knowledge of the point spread function and the space variance of the PSF in the Wide Field/Planetary Camera, HST's most frequently used imager. The best restoration results to date have been obtained by utilizing observed PSFs (an optimal exposure which minimizes noise and image defects) on small enough subsets of the total field of view so that the PSF variation can be ignored.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The spherical aberration of the primary mirror of the Hubble Space Telescope has seriously reduced the sensitivity and degraded the resolution of images and spectra from the instruments onboard the satellite. In this paper, we describe the nature of the aberration problem and the resulting point-spread functions for both the imaging and spectrographic detectors. A number of image restoration algorithms have been evaluated for use on HST data, including both linear and non-linear techniques, and sample results are shown for a modified Richardson- Lucy method. The best prospects for obtaining improvements in the restored images are likely to derive from developing techniques for adaptive regularization.