BinX and Astronomy
Bob Mann
Institute for Astronomy and
National e-Science Centre
BinX and Astronomy
„
The Virtual Observatory concept
„
Astronomical data formats
‹ FITS and VOTable
„
Possible Use Cases for BinX in the VO
‹ Further requirements
The Virtual Observatory
Federation of the world’s significant
astronomical data resources, plus the tools
required to exploit those data scientifically
„ Based on web (later, Grid) services
„ Coordinated projects around the world
‹ UK: AstroGrid
„ Forced discussion of interoperability issues
„
Astronomical data formats
FITS – Flexible Image Transport
System
Near-universal in astronomy
„ Extended to handle non-image data
„ FITS binary table preferred format for
transporting large amounts of tabular data
„ Only used in astronomy – poor leverage of
generic software
„ Difficult to stream FITS data – no. of rows
has to be specified
„
VOTable
New XML standard for tabular data
„ Design allows easy translation from FITS
„ Usual XML advantages…
‹ Flexibility, validation, streaming, etc
„ …and disadvantages
‹ Verbosity – serious problem in astronomy
„
Three flavours of VOTable
TABLEDATA
‹ Metadata and data in fully tagged XML
„ FITS
‹ Metadata in XML, data in external FITS
file, linked from VOTable document
„ BINARY
‹ Metadata in XML, data encoded in binary
format and included in VOTable doc
„
How can BinX help the VO?
Conversion between FITS binary
tables and VOTables
„
„
„
„
Lots of legacy FITS data files around
First step in eDIKT BinX testbed
Conversion to TABLEDATA works
what about FITS & BINARY?
‹
Can also strip metadata from headers of
non-bintable extensions (e.g. images)
Aiding data transport in the VO
Site 1
Database 1
WAN
Site 2
Database 2
VOTable
VOTable
Application
BinX
Binary
VOTable
BinX
Delivering SAX events with BinX?
Site 1
Database 1
WAN
Site 2
Database 2
VOTable
VOTable
Application
BinX
Binary
SAX events
BinX
Integrating BinX and databases?
Site 1
Database 1
BinX
WAN
Site 2
Database 2
BinX
SAX events
Application
SAX events
Binary
BinX
Querying BinX’s implied XML
representation with XQuery?
Site 1
WAN
Site 2
Database 2
Database 1
BinX
BinX
XQuery
SAX events
Application
XQuery
SAX events
Binary
BinX
Summary
The requirements of the VO and the aims of
BinX seem well matched
„ Initial results from the astronomy testbed
are encouraging
„ Astronomy would benefit from a number of
the possible extensions to BinX:
‹ Java version – aid integration with VO
‹ Support for SAX as well as DOM
‹ XQuery on implied XML representation
„