The WFCAM concept has been in development since early 1998. The idea of surveys in a loose sense has always been part of the science case for WFCAM. However the first proposal for a very large survey taking several years and operated as a public project in the manner of the UK Schmidt surveys was made in a paper to the GBFC by Lawrence et al. in September 1998. A formal proposal was made to the UKIRT Board in November 1999, who requested an open Announcement of Opportunity to allow all interested UK astronomers to participate. This was extremely successful, leading to the establishment of a consortium of 61 astronomers from many different organisations. Several meetings, and two workshops in Japan, led to development and organisation of the science goals, and the invitation to several Japanese astronomers to participate. The proposed survey programme is the UKIRT Infrared Deep Sky Survey (UKIDSS), and the consortium refers to itself as the UKIDSS Consortium. The consortium is the list of individuals, not the list of their employing organisations.
The consortium is not requesting proprietary data rights. The proposal is to collaborate to produce an ambitious survey programme with the intention that it is immediately open to all UK astronomers, plus individual Japanese astronomers within the consortium, and open to all astronomers world-wide after some initial UK ownership period. This document concentrates on making the science case for such a survey programme. Some discussion of how it will be implemented in practice is presented in later sections.