
FASTRAK MANUAL
Rev. G
C-3
JUNE 2012
Direction Cosines
The cosines of the angles between the receiver’s x, y, z-axes and the X, Y,
Z axes of the measurement reference (alignment) frame.
EEPROM
Electronically Erasable Programmable Read Only Memory. Memory that
can be altered by the 3SPACE, but is not lost when the power is OFF.
User default data is stored here, as well as the system identification data.
Elevation
Coordinate of orientation tracking in the vertical plane where an increase
in the angle is upward from the horizontal. A term often substituted for
elevation, especially as it concerns flight, is pitch.
Factory Defaults
The values assigned to certain system variables by the factory. Stored in
PROM, they are used to reinitialize the variables if EEPROM is lost.
Format
The interchange coding used to present data. The 3SPACE outputs either
ASCII or BINARY data, but accepts only ASCII inputs from the host.
Hemisphere
Because of the inversion symmetry of the magnetic fields generated by the
transmitter, there are two possible mathematical solutions for the X, Y, Z,
position coordinates for each set of receiver data processed, and the
3SPACE is unable to determine which solution is the correct one without
additional information. Therefore, only half of the total spatial sphere
surrounding the transmitter can be utilized at any one time for
unambiguous position measurement.
The selected hemisphere is referred to as the “current hemisphere.” It is
defined by an LOS (line-of-sight) vector from the transmitter through a
point at the zenith of the hemisphere, and is specified by the direction
cosines of the chosen LOS vector.
The orientation coordinates do not have a two-solution spherical
ambiguity and are therefore valid throughout the operating sphere centered
at the transmitter.
Host
Any device capable of supporting an RS-232C interface or the high speed
USB interface when available and capable of bi-directional data
transmission. Devices may range from a dumb terminal to a mainframe
computer.
Increment
The minimum movement necessary to cause the 3SPACE to transmit a
record to the host.