Memo Review

Memo: 352 - Design and Development of 183 GHz Water Vapour Radiometers
      Hills et al., 2001Mar

Reviewer: Dave Woody

Date Received: 2002Aug09


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.