NVOSS 2008 Course Abstracts

Welcome and Introduction

Williams, 30 minutes

Logistics. The aims and objectives of the Summer School.Introductions of faculty and students.

NVO Inside -- Overview of VO

Hanisch, 45 minutes

An overview of what the VO is and what it is not.

Software library installation and overview

Graham, 30 minutes

This presents an overview of the summer school software package and affords an opportunity for students to ensure that all the software they require for the summer school is correctly installed. Faculty will be on hand to provide support.

VO Science Goals and Discussion

DeYoung, 60 minutes

An overview of astronomical science with the Virtual Observatory.

Discovery and Exploration Tools and Libraries

Miller, 45 minutes

We present an overview of the different tools and libraries which can be used to discover and explore data in the VO. We focus on three mediums: web browsers, desktop tools, and code libraries. The goal of this talk is to provide users and developers of the VO with a high-level understanding of how the VO can be explored and accessed.

Protocols and Standards Overview

McGlynn, 45 minutes

This talk tries to give the big picture of the of the protocols and standards that will be discussed later in the Summer School. While we will talk about each of the standards and protocols individually, the real goal is to show how the pieces of the VO fit together to provide powerful capabilities for scientists and developers.

VOTable Introduction

Fitzpatrick, 30 minutes

This session will provide an overview of the VOTable document structure, the relationship between VOTable and other VO standards such as UCD and community standards such as FITS, use of VOTable in data access protocols (e.g. SIA, Cone, SSA), software libraries for reading/writing/transforming files and proposed extensions to the protocol. Students will learn how VOTables may be generated by data providers or consumed by client applications and services, and what tools currently exist to enable either.

NVO portal

McGlynn, 45 minutes

The Virtual Observatory Discovery Portal is a suite of interacting tools that enables users to find and access data resources thoughout the Virtual observatory. Elements of the portal include simple text searches for data, table querying and filtering tools and services that enable users to find information at one or more location in the sky. This talk will illustrate how the portal can be used in a variety of science scenarios.

NOAO portal

Miller, 30 minutes

The NOAO Portal provides graphical based discovery, access, and analysis of VO imaging data. It also acts as the secure data delivery system for NOAO PIs via VO Single-Sign-On technologies. We highlight the features of the NOAO Portal and briefly discuss how the VO enables such portals to be easily designed and built.

VO for mobile devices

Fitzpatrick, 20 minutes

Network access is now common on many mobile devices, allowing astronomers to use the VO from practically anywhere. While data access is not really practical from mobile devices, simple queries to see if an idea has merit can be answered using a cell phone. In this not-so-serious session, we'll look at a number of small applications that exploit increasingly powerful mobile devices to access the VO and discuss other applications that could be developed by motivated students.

VO Registry overview

Finding services in the Registry

Greene, 45 minutes

This exercise will be a tour of how to use the VO registries to find what you are looking for. We will explore IVOA registry space and look at some basic differences in the interface capabilities for the discovery and selection of astronomical resources. In this session, we'll show how to query the Registry from inside a program. We will focus on a few libraries, including a Java library that takes advantage of the standard search interface that supports both simple keyword searching as well as advanced queries that constrain specific resource metadata. We'll also demonstrate how to pull information out of the returned descriptions.

Image Visualization

Tody, 30 minutes

Visualization tools are among the most used tools for browsing and interacting with data. When coupled with VO, such tools provide a powerful capability to discover and interact with the vast amount of data available via the VO. In this talk we will survey the available VO-enabled image visualization tools (such as Aladin) and explore their capabilities for interacting with image and other data in the VO.

Topcat: VOTable on the Desktop

McGlynn, 20 minutes

TOPCAT is a very powerful tool for searching, plotting and manipulating tables including astronomical catalogs. TOPCAT can handle tables in standard VO and non-VO formats and can convert data amongst these. In this talk we will show some of the capabilities of TOPCAT and lead some simple exercises.

WESIX: Source Extraction and Crossmatch Service

WESIX provides web service and web page access to source extraction and crossmatching services. We will explore how to use these services in a real world exercise by calibrating an image against known photometry.

VIM: Multiple sources, Multiple Archives

Williams, 45 minutes

VIM is a tool for researching multiple sky positions simultaneously. Each source becomes a row in a table, with catalog, image cutouts, and spectral information. This information is drawn from all the published surveys of the astronomical literature. Vim will be presented as both web-based service, and as a downloadable package.

VO from the command line

Fitzpatrick, 45 minutes

In this hands-on session, we will introduce the VO-CLI tools that can be used to access VO data and services from the terminal command line. Students will use the VO-CLI tools to query the Registry for resources, access data, and learn how to use the various options to for queries for specific types of data. Use of these tools in building CGI web applications and from various scripting environments will also be discussed.

VO Analysis using local utilities

Fitzpatrick, 30 minutes

This session will continue the introduction to the VO-CLI tools, and using a variety of desktop tools in a science use-case to construct a Tully-Fischer relation from data queries.

Using IDL with VO

Miller, 30 minutes

In this lesson, we discuss how astronomers can integrate VO services into their day-to-day research activities using IDL.

Using IRAF with VO

Fitzpatrick, 30 minutes

This lecture will introduce users to the VO capabilities recently integrated into IRAF. These include a new version of the IRAF CL that has built-in VO functionality to query Registry and data services, a new NVO external package providing a basic toolbox of VO tasks, a discussion of how these can be combined to create new science applications or easily integrate VO functionality into traditional IRAF analysis.

Build a Google Sky Layer

Krughoff, 20 minutes
KML (Keyhole Markup Language) provides a mechanism for displaying astonomical data and images in 3D data visualization environments. In this lecture we will discover how to place placemarks and images in Sky in Google Earth.

Your VO Project and Past Projects

DeYoung, 30 minutes

Introduction to SQL and ADQL

McGlynn, 45 minutes

This presentation starts with a brief description of relational databases. It continues with an overview of the basic Structured Query Language (SQL) commands for querying tables. Users will be shown how to use SQL using existing on-line resources. The talk will also discuss the differences between SQL and the developing Astronomical Data Query Language (ADQL) being developed in the VO.

Using the VO to Study Clusters of Galaxies

Miller, 60 minutes

In this lesson, we discuss how astronomers can integrate VO services into their day-to-day research activities. We focus on a single research topic: clusters of galaxies, and specifically on the brightest galaxy population within the SDSS C4 galaxy cluster catalog. We use the VO to access the data we need from a variety of sources and combine them into a full scientific analysis.

Introduction to XML

Greene, 30 minutes

This is an introduction to the EXtensible Markup Language (XML) as a common tool for data manipulation and transmission. We will go over the basic description formats of XML documents, explain how to describe your own data types, and provide high level examples of XML used throughout the VO framework.

Fetching VOTable from the VO

McGlynn, 30 minutes

Python Introduction

Williams, 60 minutes

This lecture will introduce the Python programming language to those whose programming experience may be a different language. Topics will include list and dictionary, from scripts to classes, reading files and URLs, string and format methods, file system and OS calls, and some of the many libraries that come with Python.

Working with XML

Greene, 30 minutes

In this lecture the students will have hands on materials presented for working with the high level examples provided in the Introduction to XML and be guided through a set of XML parsers using Java and Python to demonstrate capabilities in programmatically reading XML documents.

VOTable: Python and Command Line

Williams, 30 minutes

Explanation of how to read and manipulate VOTables from Python code or by command line via the powerful Stilts command line interface.

Space Time Coordinates in the VO

Greene, 20 minutes

The Space Time Coordinate (STC) data model developed as a VO standard characterization of astronomical data will be described and explored at a basic level. The students will also be presented with different applications in the VO which rely on the STC with some real use case technical representation demonstrated.

Footprint Services and indexing the sky

Greene, 30 minutes

In this lecture the students will be introduced to the concept of 'footprints' as spatial descriptions of astronomical data. We will explore the idea of creating footprint services which describe hierarchical layers and explore the efforts in the VO to develop standard services for developing capabilities of performing highly distributed spatial queries. The students will also be provided with working footprint service demonstrations as tools to further their understanding.

Build a World Wide Telescope Tour

Williams, 20 minutes

Demonstration of the powerful visualization environment from Microsoft, including virtual observatory access, and the ability to make rich multimedia presentations.

Data Access Layer Clients (Python)

Advanced XML: Schema, XPath, XQuery, and XSL

Plante, 30 minutes

In this session, we will introduce four important XML technologies used in the VO--XML Schema, XPath, XQuery, and the XML Stylesheet Language (XSL)--and we will briefly explore two of them (XML Schema and XPath). We will show examples of these two technologies in action, describe how each is used in the VO, highlight the major components, provide you with tips on how interpret samples using these techonologies. The aim is not to make you proficient enough to compose your own uses from scratch, but rather to recognize what existing samples are doing. In some cases, you may be able to tweak an existing use to your own purposes; in others, it may help you debug an application that uses the XML technology.

This lecture has been adapted from an hour-long version that also takes a closer look at XQuery and XSL. You can explore these on your own by reviewing the full lecture slides and trying out the exercises. Alternatively, you can read Chapter 57 which covers this topic in the NVO Book.

Introduction to Open SkyQuery

Graham, 30 minutes

This hands-on session will introduce the Open SkyQuery service that enables querying distributed astronomical catalogs and performing intercatalog operations such as crossmatching. We will focus predominantly on the browser interface but will also mention the web service interface for programmatic access.

Advanced SQL

Structured Query Language (SQL) is the most popular language for communicating with relational databases. This lecture will introduce sites which make available SQL communication with astronomy data.

Correlating Catalogs on the Web

Miller, 30 minutes

In this exercise, we will use the following VO tools: Open SkyPortal? , Topcat and VOPlot . Our goal in this exercise will be to construct a diagnostic diagram for differentiating galaxies with active nuclei from galaxies with intense star formation. We will do this by first cross-correlating a sample of galaxy positions with their available spectral line measurements using Open SkyQuery. We will then cross-match the different line measurements on our dekstop using Topcat. Finally, we will plot the results using VOPlot.

WCSFixer: Correct the Astrometry

Fitzpatrick, 20 minutes

We will look briefly at the WCSFixer web application used for doing WCS corrections to single images. Aspects of how the application were constructed to provide the interface will be discussed, we will also look at the shortcomings of the current approach, how the application might be improved in the future using a different astrometry engine and how the application could be migrated for use on the desktop to solve multiple images.

Desktop Messaging

Fitzpatrick, 20 minutes

This session will quickly introduce a new VO protocol (SAMP) for messaging between desktop applications and demonstrate its use. The precursor system, PLASTIC, will also be demonstrated since this is already available in a number of applications during the migration to the new standard. We will also briefly discuss how messaging might be used in new applications.

Basic Concepts in Data Mining

Borne, 60 minutes

Data mining is defined as an information extraction activity whose goal is to discover hidden knowledge contained in large databases, otherwise known as KDD (Knowledge Discovery in Databases). Data mining specifically involves the application of machine learning algorithms to large data. This lecture will introduce the terminology and basic concepts of data mining. A taxonomy of different machine learning methods, algorithms, and techniques will be introduced, including the primary data mining approaches: clustering, association, and classification.

Scientific Data Mining in Astronomy

Borne, 60 minutes

This lecture will be a continuation of the previous lecture. In addition, some specific examples of scientific data mining in astronomy will be given, including a reference list to some of the relevant research papers in the astronomical literature. A brief introduction of the Weka data mining package will be given. These examples and introductory materials may provide useful ideas and capabilities for your projects.

Web services intro: get, post, rest and soap

Graham, 45 minutes

This is an introduction to the exciting world of web services. We will define what a web service is and consider the two different styles that are used today: SOAP and REST. We will review the different technologies employed by both including mechanisms to formally describe web services. Finally we will discuss how advanced features such as security, state, and asynchrony can be provided.

Browsing and coding web services

Krughoff, 45 minutes

Web services provide the means for interacting with resources in a distributed way. One the most powerful features of web services is the capapbility of calling them via programmatic interfaces. This lecture will introduce ways to interact with web services in python using several different protocols.

Introduction to VOEvent

Graham, 45 minutes

This will be an introduction to the VOEvent infrastructure, for communicating observations of immediate astronomical events, with the intention of stimulating rapid followup from robotic telescopes. The information packet itself will be described, as well as the emerging network that allows authoring, publication, subscription, and global identifiers for VOEvents.

Spectrum Data Model, Access, and Tools

Tody, 60 minutes

The Simple Spectral Access Protocol (SSAP) and the associated Spectrum Data Model were completed in late 2007, and spectrum data services and client applications which can use them are now starting to become availalbe. SSA is the first of the second generation VO data access layer (DAL) services, providing access to spectra while also defining the framework for the second generation services. In this talk we review the current and planned capabilties for spectral access in the VO, and review the spectral data services and client tools currently available for accessing and interacting with spectra.

Building Web Services

Graham, 60 minutes

This hands-on session will show how to expose code as a web service (both SOAP-based and RESTful) in Java (using the Apache Tomcat servlet container and Apache Axis libraries) and Python (using the CherryPy? library).

Build a cone search service

Tody, 30 minutes

The Cone Search service is used to query a source catalog to find all objects within a given circular (cone) region on the sky. The simple cone search was the first and simplest VO data service, and is still quite useful today. It illustrates the essential characteristics of the more complex VO data services which followed, such as SIA and SSA. In this lecture we look at what is required to implement a cone search service, looking first at what is required to build a cone search service from scratch, and then introducing the concept of a service framework and showing how this can be used to implement a cone search.

Data Access Layer Servers

Tody, 60 minutes

The VO data access protocols are defined purely as Web protocols, independent of implementation, allowing anyone to implement a new service protocol to publish data to the VO. As the VO framework evolves and becomes more sophisticated however, it becomes more difficult to implement compliant, correct, and robust services completely from scratch. The use of a data service framework addresses this problem, making it much easier to implement fully compliant and functional data services, focusing the effort upon the data to be accessed rather than the protocol. In this talk we introduce the DALServer framework being implemented by NVO to provide a ready-to-use framework for building VO data services.

Publish a service in the VO

In this session we'll explore what it means to publish data to the VO. Central to the publishing process is the VO Registry that contains descriptions of useful things in the VO. We'll look at VO Registries, the descriptions they hold, how to create new descriptions and how to get them out again.

VO Science with Cross-correlations

Krughoff, 60 minutes

The VO is a powerful tool for doing science. This lecture will present an end-to-end example of how to do exploratory astronomical science in this new paradigm.

Future of the VO