Memo Review Memo: 352 - Design and Development of 183 GHz Water Vapour Radiometers Hills et al., 2001Mar Reviewer: Dave Woody Date Received: 2002Aug09 Review: This memo describes a very sensible development plan for 183GHz radiometric phase correction. The ideas are good and the plan and schedule are reasonably thought out. The only negative comment is that the authors understate the potential advantages of using a cooled system. The high system noise for a room temperature system puts severe requirements on the gain and spectral stability, especially in the single mixer version, since the system noise is added to the desired sky emission signal. The system noise can be reduced by a factor of 5-10 by using a cooled front end greatly reducing the stability requirements. It remains to be seen if stability is problem for this system. If it is, then a cooled system may be necessary.