I propose a new function we regularly use in our lab, called transMatrix:
it calculates the transformation matrix between 2 colocated seismometers. It allows us to estimate the components gain for calibration purposes and the orientation error between them. This works even for borehole seismometers. It uses the least-squares solution method available in numpy (np.linalg.lstsq).
Would you be interested in such a code?
I created a new file called transmatrix.py, and a dedicated unit test file (test_transmatrix.py).
I hope it's a suitable way. Let me know.
Add transmatrix.py into signal submodule
Adjust default values
Add data needed by unit test
Add unit test file
I don't have time to check this in detail right now, but it sounds like something that could fit nicely in our signal.calibration module.