Acceleration from device's coordinate system into absolute coordinate system

Question

From my Android device I can read an array of linear acceleration values (in the device\'s coordinate system) and an array of absolute orientation values (in Earth\'s coordi

Answer 1

According to the documentation you get the linear acceleration in the phone's coordinate system.

You can transform any vector from the phone's coordinate system to the Earth's coordinate system by multiplying it with the rotation matrix. You can get the rotation matrix from getRotationMatrix().

(Perhaps there already is a function doing this multiplication for you but I don't do Android programming and I am not familiar with its API.)

A nice tutorial on the rotation matrix is the Direction Cosine Matrix IMU: Theory manuscript. Good luck!