FASTRAK MANUAL
Rev. G
C-6
JUNE 2012
virtue of their principle of operation, can produce only position or only
orientation whereas others can produce both P&O (although the user
usually can opt for only those parameters desired).
Pitch
Same as elevation.
Quaternion
A four-parameter quantity representing a vector and a scalar. The
quaternion q = q
0
+ i q
1
+ j q
2
+ k q
3
can be used to represent the receiver’s
orientation without the need for trigonometric functions. The attitude
matrix output from the 3SPACE can be equivalently represented by the
following matrix using quaternions:
X Directional Cosines Y Directional Cosines Z Directional Cosines
q
+
q
-
q
-
q
)
q
q
+
q
q
2(
)
q
q
-
q
q
2(
)
q
q
-
q
q
2(
q
-
q
+
q
-
q
)
q
q
+
q
q
2(
)
q
q
+
q
q
2(
)
q
q
-
q
q
2(
q
-
q
-
q
+
q
2
3
2
2
2
1
2
0
2
3
0
1
2
0
3
1
1
0
3
2
2
3
2
2
2
1
2
0
2
1
0
3
2
0
3
1
3
0
2
1
2
3
2
2
2
1
2
0
Receiver
The receiver measures the low-frequency magnetic field generated by the
transmitter. The receiver is used to track both the position and orientation
of the object to which it is attached, relative to the measurement reference
frame.
Roll
Coordinate of orientation tracking about the azimuth-elevation axis where
an increase of the angle is clockwise as viewed from behind or in the same
direction as the object is facing.
Sensor
Same as Receiver.
Station
The transmitter-receiver pair. Up to four receivers are permitted, yielding
a possible four stations.
Stylus
A pencil-shaped housing for the receiver with an integral switch and used
by the operator to indicate and/or select points to be digitized.
Sync
Shorthand for synchronization. For example, sync signal.