Collaborative Page for SIA Interface

The Simple Image Access (SIA) interface defines a protocol for retrieving image data from a variety of multidimensional astronomical image/cube repositories through a uniform interface. The interface is meant to be reasonably simple to implement by service providers. A query defining a multi-parameter query is used to query for candidate images. The service returns a list of candidate datasets formatted as a VOTable. For each candidate image an access reference URL may be used to retrieve the image. Direct client-directed access to a remote image/cube dataset is also provided. Images may be returned in a variety of formats including FITS, other astronomical image formats, and various graphics formats. Referenced images are often computed on the fly, e.g., as cutouts from larger images.

Current SIAV2 Working Draft

The SIAV2 working draft has been split into two closely linked documents, the SIA version 2.0 specification per se, and the Image data model it is based upon. This version of SIA, and the new Image data model, are fully multidimensional and capable of dealing with cube data. The SIA-2.0 working draft is available in the document repository:

http://www.ivoa.net/documents/SIA/

The latest ImageDM working draft is available from the DM-WG pages.

Siav2RFC page

Older drafts and Related Papers

• Simple Image Access V1.0 (Current/legacy SIA V1.0 specification)

• Simple Image Access V2.0 (SIAV2 working draft as of fall 2013)

• Simple Image Access V2.0 (SIAV2 working draft as of fall 2009)

• VAO Whitepaper on Multidimensional (cube) Data in the VO (May 2013)

• Providing Support for n-Cubes in the VO (Rots et. al. 2013)

• Characterization V2 draft addressing visibility data (September 2012)

• Interferometry (radio) data and the required SIAV2 capabilities (A.Richards, February 2010).

A major update to the SIA interface, SIA V2.0, is in the planning stages. A partial working draft is available at the link above, as well as related analysis papers as noted on this page.

SIA Related IVOA Notes

• SIAV2-Analysis.pdf (Scope and Concepts of SIAV2)
• DAL2_Architecture.pdf (DAL2 Service Architecture and Standard Profile)
• Polarization.pdf (Note on polarization, primarily referring to radio data)

VAO Prototyping Effort

The VAO Project is building a prototype SIAv2 service for presentation and demonstration at the Fall 2013 Interop. More information on the scope and progress of this effort can be found in the SIA2VAOPrototype page.