The WFCAM/UKIDSS data archive: problems and opportunities

The UKIRT Wide Field Camera (WFCAM) is an IR mosaic camera that represents an enormous leap in deep IR survey capability. It will be used as both an open time facility, and to perform a public IR Deep Sky Survey (the UKIDSS project), starting in early 2004. Here we present current plans for the data archive system, which will be provided as a standard service for all UK WFCAM data whether private or public survey data. The data rate is an order of magnitude larger than any previous survey experiment. WFCAM is therefore a crucial stepping stone between current day surveys such as SuperCOSMOS, APM and SDSS, and future facilities such as VISTA and the LSST. Pipeline processing presents a technical challenge, but the strongest challenges come in operation and curation of such a pipeline and of the rapidly accumulating database. For the public archive, there is little technical challenge in simply storing the data, and the real challenge comes in the rapidly increasing expectations of the user community for the kind of on-line services available with the archive. We describe three levels of archive service and the challenges they present, and discuss the hardware and software solutions we are likely to deploy.