I want to perform some geophysical studies with three 3D units that I purchased a few months ago. This is the first time I turned one unit on (due to the quarantine), and all the recordings have a constant offset in each component.
I am importing and processing the miniseed recordings in Geopsy, and this is what every original recording looks like:
It looks like the N-S and vertical components have a strong positive offset, while the E-W component is negatively offset.
Geopsy has a detrending function that can remove this offset, making it look like a normal recording:
I was wondering if this was normal, has anyone ever seen anything like this? I will test the other two units over the next few days, and report if they also have the same offset.