Abstracts for Applications Interest Group Sessions at the May 2006 IVOA Interoperability Meeting

VOQuest is an application that provides access to services implementing a specific data model. To do so, VOQuest makes use of a bunch of VO standards and protocols like ADQL, VOTable, SkyNode and PLASTIC. Besides that, this tool is able to interoperate with existing VO applications like VOSpec, Topcat and Aladin to relegate some specific functionality already present in such tools in mature state. As a technology demonstrator this application, and the architecture hidden beneath it, is at a prototype stage.

TOPCAT is an interactive application for manipulating tabular data such as source catalogues, increasing in popularity with VO and non-VO users. Version 2.0, released Feb 2006, provides considerably improved visualisation facilities including histograms, density maps and 3-d plotting. A demonstration of these new features will be given.

WCSFixer was one of high-priority apps identified by the NVO Science Steering committee and provides a method for solving/improving the WCS of images. It uses standard VO protocols for accessing reference catalog data and makes use of legacy software (IRAF) to do the computation. Additional VO Tools (i.e. the STILTS toolkit from Mark Taylor) are used to manage VOTables in the legacy environment and the webapp itself is simply a CGI-POST script with embedded JavaScript to drive the interface, however standard SOAP/WSDL web services and desktop client applications to call it remotely as a commandline task will soon be available as well. It is currently undergoing revision with a new version expected in time for the meeting. Community usage has exposed data-quality problems/issues for real-world applications, as well as limits imposed by choice of algorithm.

Using mapping packages from the geophysics community and the World Wind interface developed by NASA, we have created a number of tools for visualizing astronomical data on the sky. The interface projects imaging data as well as footprint maps (coverage, overlap and background) onto the sphere and allows users to scan around the sky, zoom and overlay different data sets on top of each other. Images are generated in a range of resolutions, dynamically served to the client using a Web Mapping Server (WMS) based on the current viewing window and projected onto the sphere. Our WMS server at Pitt is currently serving maps for the fourth Sloan Digital Sky Survey data release (SDSS DR4) and the Wilkinson Microwave Anisotropy Probe full sky cosmic microwave background map as well as coverage maps for the SDSS DR5 and the FIRST radio survey. Since we went live in mid April we have served nearly 90GB of imaging to roughly 80,000 unique IP addresses from all over the globe.

We demonstrate the new Java / JavaScript version of DataScope and a distributable version of the SkyView virtual telescope. The new DataScope illustrates how AJAX technologies can make Web based VO experiences more responsive. The SkyView-in-a-Jar illustrates how the VO's SIA protocols exactly complements the internal geometry capabilities of SkyView.

Databases generated with Saada are designed to host heterogeneous data collections. In this context, data can be selected by providing collections with some common interface such as a common spectral coordinate system and by expressing contraints with UCDs.

Basecol is a combination of a website (using PHP and HTML) and a MySQL database concerning molecular ro-vibrational transitions induced by collisions with atoms or molecules. This database has been created in view of the scientific preparation of the Heterodyne Instrument for the Far-Infrared on board the Herschel space observatory (HSO). Basecol offers an access to numerical and bibliographic data through various output methods such as ASCII, HTML or VOTable . Several services are available to access the database from client software. DALIA is an application in development that will provide a generic interface to modelisation codes. Model developers will be able to register their code in this framework through a simple procedure. An optimization engine will be provided through a GUI for fitting of the code outputs to real observations. A connection to Basecol using the SLAP protocol is implemented in order to get spectroscopic data and transmit them to the codes when they are required.

VOEvent is the new IVOA standard for representing transient astronomical events. We present our client software for subscribing and publishing VOEvent packets.

The AstroRuntime is a desktop application that serves as a bridge between user tools and external VO services. Applications written in any language can use the AR to easily access any VO service: including VOSpaces, Registries, CEA applications, SIAP servers...

2 Binding applications with PLASTIC

PLASTIC is a simple, extensible, platform-agnostic protocol for communication between desktop applications.

Aladin/Topcat interoperability using PLASTIC

Using Aladin and Topcat, I will demo what kind of interoperability can be achieved between desktop tools through the PLASTIC (PLatform for AStronomical Tool InterConnection) protocol. In particular, I will show that PLASTIC allows flexible collaborative data exploration through linked views (eg : the selection of points in one tool is being reflected in the other tool).

VODA - A Discovery and Visualisation Tool using a Virtual Directory

The Sampo project has developed a prototype general purpose VO application using standard IVOA protocols and the ACR facade from Astrogrid for access to external VO resources. VODA allows browsing and resource discovery in the VO and the management of a Virtual Directory of data references. The Virtual Directory forms a local, presistent personal view of the VO where referenced data sets may be downloaded or directly passed to visualisation tools such as Aladin, fv or DS9. We are currently experimenting with the use of Plastic as a general purpose connection between VODA and VO tools. VODA also offers the possibility for client-side applications to access VO resources via the Virtual Directory. We will describe the motivation and implementation experiences as well as giving some simple examples of VODA in action. .

We present VisIVO and its PLASTIC integration. The attention will be focused both on client and on server sides of VisIVO interoperability towards the other PLASTIC-aware applications.

In addition to a hard-coded list of FoVs for major instruments, Aladin is now able to display arbitrary instrument FoVs loaded from an XML file (whose format is described in the IVOA note ...) I will demonstrate how those FoVs can be loaded and manipulated in Aladin. The user can move or roll each FoV, hide or show some subparts, and monitor those changes through the Properties window or through the standard input via the Aladin script commands.

A FoV can be displayed on its own, or be linked in a VOTable document to a given observation, for instance in an observation log. This FoV feature is notably being used by the APT (Astronomer's Proposal Tool) software, in conjunction with the VOApp interface.

Comparison of the VOApp solution and the PLASTIC solution.