
FASTRAK MANUAL
Rev. G
C-1
JUNE 2012
APPENDIX C. Glossary
6DOF
The
6
D
egrees
O
f
F
reedom (XYZAER) needed to define the position and
orientation of an object in 3D space.
Alignment
Obtaining congruence between the axes of the tracker and the axes of the
application. For active technologies, this is often the same as aligning the
active element from which all measurements are referenced. Alignment in
an active system is not the same as a boresight operation, which concerns
only the receiver. Only in passive systems, alignment and boresight can be
identical.
Alignment Frame
The reference frame in which the position and orientation of the receiver is
measured. The default alignment frame is the transmitter frame.
ASCII
American national Standard Code for Information Interchange defines a
certain 8-bit code for display and control characters.
Attitude Matrix
A three-by-three matrix containing the direction cosines of the receiver’s x
axis in column one, the direction cosines of the receiver’s y axis in column
two, and the direction cosines of the receiver’s z axis in column three. The
order of the 3SPACE Euler angle rotation sequence is azimuth, elevation,
and roll.
X Direction Cosines
Y Direction Cosines
Z Direction Cosines
CA*CE
SA*CE
-SE
CA*SE*SR - SA*CR
CA*CR + SA*SE*SR
CE*SR
CA*SE*CR +
SA*SR
SA*SE*CR – CA*SR
CE*CR
where:
CA = Cos (azimuth)
CE = Cos (elevation)
CR = Cos (roll)
SA = Sin (azimuth)
SE = Sin (elevation)
SR = Sin (roll)
Azimuth
The coordinate of orientation tracking in the horizontal plane where an
increase in the angle is clockwise when viewed from above. Azimuth is a