The data stored in our output files (csv and hdf/h5) are all in the sensor's frame of reference. For example, the x-axis gyroscope data all refers to rotational velocities about the movement monitor's x-axis. For some applications, it is desirable to have inertial data (accelerometer, gyroscope) in the Earth's frame of reference. To facilitate this, we provide estimates of the movement monitor's orientation. We accomplish this with an algorithm that fuses the accelerometer, gyroscope, and magnetometer data. The orientation data can then be used to transform your sensor frame data into Earth's frame of reference.
In this forum topic, we provide two Matlab scripts which enable you to make this conversion. Here is an example of this transformation:
gyro = h5read('foo.h5', '/SI-000111/Calibrated/Gyroscopes')';
orientation = h5read('foo.h5', '/SI-000111/Calibrated/Orientation')';
angularVelocityEarth = RotateVector(gyro, orientation);