Hijacked thread indeed - but since you asked -
At first glance has nothing to do with a 10V reference, but everything to do with studying "correlated noise events" on a grand scale.
http://en.blitzortung.org/cover_your_area.phpCheck out the real time map and project schematics.
In a nutshell - If you're looking for E-field ripples from closer T-storms, your antenna is a length of wire. For Mag fields that travel through and around Earth, just about any circuit loop that encompasses a non-zero area is a potential lightning detector antenna. Add some gain with an op-amp and some filtering. Add a GPS to timestamp interesting noise pulse events that look most like a lightning stroke.
Project users from around the world send their data to a central cloud server and let it crunch the numbers - and then a few seconds later you have a near real time lightning map. This is a Time of Arrival detection system that works best when lots of users are participating.
In other words - once you've "correlated" your noise pulses with hundreds of other users on Blitzortung - the end result is a fairly accurate map of lightning strokes around the world. Sometimes a stroke event will trigger a few detectors, sometimes you'll see a bunch of detectors contribute to the stroke position solution Every detected stroke is logged for later analysis.
What does this have to do with measuring References?
Once you start using a lightning detector, then you start keeping an eye on that local signal output while you're taking sensitive measures in the lab....and then you start to realize that some of your noise you see on your Vref isn't exactly random.
Somewhere around then you also realize how far away that storm is that's tickling your circuit. If you're timestamping your data carefully, then sometimes your buddy halfway around the world can easily be observing the same noise events on his data. It happens, ESPECIALLY when you're chasing low ppm or very sensitive measures.
This is a type of worldwide interfering noise source that requires no mystery physics of any kind to complete the explanation.