Project under consideration. (Design, too.) Requirements:

  • GPS receiver with PPS output
  • Small power transformer
  • Raspberry Pi
  • USB audio interface
Connect PPS and transformer output to USB audio input (which is conveniently stereo). Connect GPS serial to Raspberry serial port. Log power phase against PPS signal. Get Internet connectivity.

USV not needed. When there is no power then what we want to monitor isn't there either.

From logs, compute the total phase fluctuations over time, which is the amount that clocks that use the line frequency as time reference would deviate from true time. Also look at the spectrum of the frequency fluctuations.

And realtime display of these quantities.