Mysterious signals

Hi all,
Apologies as this is my first time posting. I have a raspberry shake installed on the ground floor of my house in the living room. We own a tumbledryer and a washing machine, and the boiler is upstairs. We are middle terrace in a row of 4, none of which are causing the phenomenon (we have extensively checked).
There is an intense signal for a few hours in the middle of the night/late evening (see screenshots) (most nights, not all, and not at regular time intervals) someone is trying to tunnel out of our house/row/road. I have shown this to several geophysicists (I am a geologist so I have access to geophysicists), and they are all stumped and very curious.
Any help will be appreciated!
I don’t think it’s a technical problem, although it very well could be, but we’ll start with the tunnelling theory (I don’t actually think/hope someone is tunnelling out but I’m really stumped for other suggestions!).
Any suggestions/help would be greatly appreciated!


If you can show they spectrograph, that may help.
Tracking down these sorts of things can be quite time consuming and frustrating…


Overnight road resurfacing works?

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Hello Lauren, and welcome to the community!

Yes, as Philip said, if you could post the spectrograms for those interesting time periods (you can access them more easily on our DataView portal: we could try to provide more insight into what you have captured.

From a general first look, the first signal (multiple spikes) could definitely be roadworks, as Hadders has suggested, while the second (more compact and continuous signal) could be the activation of some kind of large machinery in the neighborhood.

i was thinking “fun”, but then, that’s just me… :upside_down_face:


Is this the time you are talking about in the last screenshot?

If it is, the background noise (<20Hz) is more intense bit there’s a higher frequency at about 35 to 37Hz around this time. There’s also some smaller ramps and constant frequencies about 15Hz.



I hardly dare ask what you are defining as “fun”?
And how you make it last pretty much all night!

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