Linear Acceleration - Sinusoidal behaviour when in air
I am using an MMR sensor to record linear acceleration. I have noticed when the sensor is airborne, the z-axis (g) shows sinusoidal behaviour if the sensor is rotating when in the air (second yellow circle). Linear acceleration is in earth frame, therefore I expect that the z-axis acceleration should be constant (only gravity) when in free fall. This usually occurs as expected when the sensor is not spinning in the air (first yellow circle).
Do you know why this is happening? Is it specific to my sensor or is this common behaviour? (Test by throwing sensor into the air)
Phone: Google Pixel 3a