This comparison was suggested to help evaluate whether the narrow line contamination seen around violin mode regions during ring-ups is related to aliasing. The idea (as I follow it) is that because the 64 kHz channel has different aliasing, the noise ought to look different in the two channels if it is aliasing-related. In fact the two channels look similar, albeit not identical, which looks like evidence against the aliasing hypothesis. However, this test may not catch all the places where aliasing could occur, so it may not be conclusive. See the associated detchar-request issue for ongoing discussion.

The first two plots are from 2023, during time periods which were previously identified as having line contamination around the violin modes (71800, 79825). The last plot is from just a few days ago, on Jan 12.