LIS2DW12 celestial gravity

[meco]

Hello

If a device using LIS2DW12 is fixed in a fixed position, will it be affected by the gravitational pull of the sun or moon and will the gravitational acceleration of each axis change?

[Federica Bossi]

Hi @meco ,

Welcome to ST Community!

To cut the continuous earth gravity and see only the vibrations you apply on the sensor, you could enable the high pass filter to easily delete the DC component of the measured acceleration. Please, look at section 3.5 of the AN5038

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A high pass filter is not going to work.  The period of the moon tidal effect is 12 hours and 25 minutes. That's 22 microHertz. A low pass filter would be needed to measure it. The signal is only 30 milli gals (1 gal is 9.81ms^-2) so I don't know if that can be measured as I'm not familial with the sensor resolution and noise. Perhaps a decimating filter in post processing can increase the resolution enough to detect a signal in all the noise.

EDIT: it is not clear from the topic title or post if the goal is to measure the celestial gravity or the goal is to have the measurement not affected by it. No details are mentioned. I assumed since celestial gravity was mentioned in the title that that was the goal. But I now realize this may not be the case. Simply measuring orientation or acceleration will not be affected by such a small and slow variation in gravity.