I was calculating the Allan deviation (utilizing the Python module allantools.adev, which relies on eq. (6) in https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50505). The expected behavior is a linear decrease as the system exhibits white frequency noise:
This expected linear decrease can be observed up to an averaging time of about 0.1 s. However, for longer averaging times the Allan Deviation starts to decay very rapidly. Has anyone observed such behavior and do you have an idea of how to interpret this/where it originates from?
I would be very grateful for your help and insights! :)