Figure 10:
The Cosmic Anisotropy Telescope, shown shortly after its completion
in July 1993, together with members of the group who participated in
its design and construction.
The Cosmic Anisotropy Telescope (CAT; see Fig.10) is a three-element interferometer designed to study primordial anisotropies in the Cosmic Microwave Background Radiation in the 12-18GHz band on a scale of about 20arcminute. During the early part of the period covered by this report, the CAT was in its final stages of construction and commissioning, beginning its deep observing programme in the Autumn of 1993. Its performance has been excellent, and it has already produced good results (see section 1.1.1). We have had few periods when the instrument has been out of action because of breakdown or design problems, although we did need to improve the elevation driving mechanisms early in the observing programme. We have also completed the data networking to the CAT control room, enabling data to be transferred and CAT operations reliably monitored.
The problem of detecting statistical signals in interferometer data has been considered by Hobson et al. (in press), who have developed a Bayesian likelihood-analysis technique for characterising the amplitude and coherence scale of CMB anisotropies directly from visibility data.