FASTRAK MANUAL
Rev. G
C-4
JUNE 2012
I/O latency
The interval of time needed by the host computer to transfer tracker data
from the tracking system into the host application.
Lag
The total time from motion data sample capture to host inputting where
the data are ready for application use.
Line of Sight (LOS)
1) The orientation angle of the tracker receiver. 2) In active tracker
systems, the angle between the source of stimulation and the tracker
receiver. 3) Not obscured or blocked from view, such as a clear line of
sight for optical uses.
LSB
Least significant bit.
LSD
Least significant digit.
MSB
Most significant bit.
Motion Box
The volume in which motion tracking is guaranteed to perform as
prescribed. Although this 3D volume usually is cubicle in nature, many of
the tracking technologies known as active are dependent on a source of
stimulation (e.g., magnetic field, light transmitter) which actually performs
equally well at a constant radius from the source so that the “box” actually
might be better described as spherical or hemispherical.
Orientation Angles
The azimuth, elevation, and roll angles that define the current orientation
of the receiver coordinate frame with respect to the designated reference
frame.
The Euler angle coordinates that are output by the 3SPACE as one
measure of receiver orientation are graphically defined in
, the x,y,z and X,Y,Z tri-axis arrays represent independent,
three-dimensional orthogonal coordinate frames. The x,y,z triad represents
the receiver frame in its current orientation state. The X,Y,Z triad
represents the reference frame against which the relative orientation of the
receiver frame is measured. By definition then, the X,Y,Z frame also
represents the zero-orientation reference state of the receiver frame.