call for presentations at the Data Model sessions in Cambridge , September 2007

[Jonathan Fay]

>> A. Allan Wrote
>>When it comes down to it, I think KML is going to start getting
>>heavily used. I think the IVOA should think seriously about putting
>>it's official blessing on such use, because it's going to happen with
>>or without it...

We obviously can't ignore the impact of KML, but while it might be one a way of interoperating, unless it is fixed it should not be the default way.

We should not give up the top and bottom 20 degrees of the sky.

We should not have to reproject images out of their native "TAN" format to equirectangular for display.

In Architecting the WorldWide Telescope client, while I provided KML integration, KML was far too limiting to use as the primary way to bring in data. Once rich astronomy hits KML it usefulness is significantly restricted. Not just visually, but more importantly the metadata is lost.

In WWT we don't just want to get imagery into the application, but the rich metadata so we know as much about that imagery, know how to get the FITS data behind it, etc. That is not possible with KML today. It is possible dealing with native VO standards. The missing part is the real-time visualization interfaces, and KML does not do a good job with that for astronomy data, at least not in its current form.

JPEG's are a wide reach vehicle, but should we transfer all astronomy images from FITS to JPEG because it's adoption is so widespread?
Of course not. KML has the same parallel. We should not consider it a substitute for standards that preserve the quality of astronomical image and metadata.

My fear is that buzz about KML will lead to widespread adoption of low-fidelity interop in place of the high-fidelity interop that the IVOA has made a mission to create. In the end the preponderance of low-fidelity services replacing high-fidelity one will lead to a dearth of rich client support. Additionally if we accept KML without it being made astronomy friendly there will be no pressure for it to adapt to incorporate the need changes to properly support astronomy.

Tools like Sky in GE, WWT, Virtual Earth and NASA World Wind have stirred allot of interest in the visualization and search of imagery and data. This in turn has fueled a growth in interest in interoperability among astronomers outside the VO community. Let's let this trend run it's course. I don't think we should be so quick to give up on astronomy based standards just yet.

Jonathan