the delta angle bias was applied to imu data which was not coming in the same
time intervall as the filter was operating. Therefore, the delta angle bias
applied to new imu data had to be scaled correctly in order to match
the imu time interval.
Use the gravity vector to estimate the initial roll and pitch angle
Use the projection of the magnetic field measurement onto the earth axis horizontal plane to calculate the initial heading
Roman
Paul Riseborough
Lorenz Meier