I have a triaxial accelerometer giving me acceleration along x, y, and z. I then combine the 3 axes by calculating magnitude of acceleration over all time points (details in my question here)
I'm wondering about the correct time in the process to low pass filter my signal to eliminate some of the high frequency noise in the signals. I guess I have a few options:
- Filter the raw xyz signals, calculate magnitude and use it as is
- Filter the raw xyz signals, calculate magnitude, filter the resulting magnitude vector, and then use that
- Use the raw xyz signals (no filtering), calculate magnitude, filter the result then use it
From a theoretical standpoint, does it matter which signals I filter and in which order?
I would imagine that if I dont filter the raw signals (#3) and directly calculate the magnitude I would end up amplifying a lot of noise? But is there a harm to double filtering (the raw signals, and then the magnitude) in #2?