Virtual Observatories,Press Release Images,
and Web Services
Dr. Frank Summers
Space Telescope Science Institute
November 3, 2005
Collaborators
• Lisa Frattare, Zolt Levay
• Phil Hodge
• Kaushi Bandara
• Bob Hanisch, Carol Christian, Nahide Craig
Virtual Observatories
• Digital data, digital connections, digital processing
• Many telescopes, many repositories, many bandpasses
• Define standards, build infrastructure & tools
Press Release Images
• Pictures worth a thousand words
• VO Problems– Heavily processed– No coordinates– Different metadata
Web Services
• User to computer
• Computer to computer
• XML – self-describing– DTDs, Schema– VOTABLE
Simple Image Access
• SIA protocol defines a web service
• Input: cone search
• Output: list of images
• Several types of services: cutout, mosaic, atlas, pointed
• www.ivoa.net/Documents
PReSS Images
SIA Info Database
SIA Query Server
Public Interfaces
NVO Interfaces
Internet
Major Tasks
• Gather image data, esp WCS
• Assemble image database
• Create web service
• Register with NVO
PReSS Archive
• STScI NewsCenter database
• Images• Metadata
– Astro info: object, category, instrument
– News info: release, primary, composite
Get WCS Info
• Identify suitable images
• Retrieve FITS files
• Run WCS Transfer Tool
Non-astronomicalCompositePrint layout
Solar system
Non-VO Images
Astronomical Astronomical w/ notation
FITS & WCS
Process FITS
WCS Transfer Tool
• FITS reference image• Public release image• Mark corresponding points
– Automatic peak identification– Automatic solution refinement
• Python program– Python imaging lib (PIL)– Matplotlib– Tk interface
WCS Results
Create Database
• Loop through WCS processed images
• Scan through PReSS
• Calculate new quantities
• Output assembled data
• Perl program
HST PR SIA Web Service
• Perl programs within Apache web server• Based on SIA 1.0 spec• Process SIA query
– Uses modified CGI::Validate
• Search database• Create VOTABLE response
– Uses GSFC’s ASTRO::VO::VOTABLE– Custom EPO fields
• All code will be available
To Do List
• Multiple image versions
• Test to production server
• Document & distribute
• Pipeline
Other Things
• AAS Astronomy Visualization Session
• Webcasts & Audience
• Einstein Opera