CF	complementary filter
GCS	global coordinate system
KF	Kalman filter
LCS	local coordinate system
MIMU	magneto-inertial measurement unit
RMS	root mean square
SFA	sensor fusion algorithm
SP	stereo-photogrammetric system
STD	standard deviation
Absolute orientation	the orientation of the local coordinate system (LCS) of a system with respect to its GCS
Absolute orientation error	the difference between the orientation of the LCS of a magneto-inertial measurement unit (MIMU) computed by a sensor fusion algorithm (SFA) and its actual orientation computed by the optical reference (SP) and expressed by the angle given by the axis-angle convention
$e_{def}$	absolute orientation error corresponding to the selection of the default parameter values
$e_{opt}$	minimum absolute orientation error which corresponds to the selection of the optimal parameter values
Optimal parameter region	the range of parameter values for which the orientation errors are equal to $e_{opt}$ plus 0.5 deg