Rotating-Stirring Process and Circular Time Series

In the context of reverberation chambers, correlations observed in stirring processes are almost always modeled by linear time series (LTS). Although this approach is known to be reasonable for sliding stirrers, it turns out that its relevance has never been discussed for rotating stirrers. For the first time, we propose to use circular time series (CTS) to model rotating stirring processes. This allows one to exhibit operational conditions under which LTS and CTS perform similarly in terms of modeling accuracy and those where CTS should be used instead of LTS; in particular, the number of stirrer positions is shown to play a key role for this choice.