In the past few weeks, a number OPO temperature changes have been made while the detector was in observing mode (per the relevant instructions). These changes have been highly successful at increasing the range, particularly the most recent couple of OPO changes. However, this type of rapid improvement in the spectrum can create challenges when measuring the spectrum of the data in downstream data analysis pipelines (similar to how the sudden turn-on of the line subtraction was problematic). When the OPO adjustment has created significant changes to the spectrum, the time periods during the transition should be CAT1 vetoed (tagging Detchar-request).

As an example of these transitions, I've included a range timeseries and a daily spectrogram with the transition time indicated.  I also have included a before/after spectrum comparison showing the broadband improvement at high frequency.

To mitigate the impact on data analysis pipelines, future transitions should either be made while briefly out of observing or tracked by Detchar for CAT1 vetoes.