Memo Review Memo: 403 - Fast Switching Phase Correction Revisited for 64 12 m Antennas Holdaway, 2001Dec17 Reviewer: Dave Woody Date Received: 2002Aug08 Review: This is difficult to review since a lot of the information is contained in AIPS++ code and glish scripts. It would help to add a more detailed or explicit description of the optimization algorithm. Not all of the references are in reference list, i.e. Butler and Wooten 1999 and Delgado 2001. I assume these are ALMA memos. It would be useful if the critical data used from the references were presented in this memo so that the reader can readily see what the assumptions are, i.e. atmospheric opacity and receiver noise temperatures vs. frequency. This information could be included in table 1. It is painful for the reader to have to go back to the references and dig out the numbers and then you are not sure they are same ones used in this analysis. The results depend critically upon the assumed 500m height for turbulence from Memo 345. The analysis is memo 345 has a few key assumptions, such as the wind speed being uniform through the atmosphere, which can effect the conclusion. It would be useful to have the fast switching results calculated for a higher turbulence height, such as 2km. In general the results are probably correct for the assumptions used, although doing a phase calibration with 18msec of data seems scary. This will be a very useful reference memo for ALMA. If the assumptions and hence the conclusions are wrong the consequences for the ALMA project are small. You will just have to refine the fast phase cal strategy, lose a little efficiency, and rely more on radiometric phase correction. But if this memo is used to justify not doing radiometric correction, then possible errors in the assumptions are very serious.