Instruction manual

Page Gloss-2 Z-12 Real-Time Sensor Operation and Reference Manual
for one specific satellite.
Fast CPD
An Ashtech proprietary differential technique
to generate position at high output rate and low
latency.
Fixed Ambiguities
The Carrier Phase Cycle Ambiguities are of
integer natures. When they can be fixed to
integers, the position accuracy is in centimeter
to sub-centimeter level.
Float Ambiguities
The Carrier Phase Cycle Ambiguities are
estimated as float numbers. With float
ambiguities, the expected position accuracy is
around meter to sub-meter level.
Integer Ambiguities
see Carrier Phase Cycle Ambiguities
IODE
Issue of Date Ephemerides
Kalman Filter
An optimal stochastic filtering which combines
the recusive least squares and stochastic process
in an optimal way. It is a widely used scheme in
navigation and other signal processing
application.
MBN
Measurement data, ASCII or binary.
Multipath
A reflective signal which contaminates the
main path of the signal. GPS multipath is one of
the major error source affecting the position
accuracy. It cannot be corrected by differential
technique, but can be reduced by situating the
antenna away from metals, water, and
obstructions.
OBN
Output message containing CPD vector and site
information. Binary only.
PBEN
CPD rover position, velocity, and other data,
ASCII or binary.
PRN
The ID number assigned to a satellite in
accordance with ICD-GPS-200, Navstar GPS
Space Segment/Navigation User Interfaces,
Revision B.
Pseudo-range
Distance measurement from satellite to sensor,
uncorrected for sync errors between satellite clock
and sensor clock.
Raw data
Unformatted data collected by a GPS receiver
RBP
Reverse baseline processing. A mode of operation
in which a rover transmits raw data to a base
station, which then computes the rover position;
that is, the base station knows the rover position.
Real-tim e K inematic
A differential GPS operation using the carrier
phase measurements with fixed integer
ambiguities. It achieves the ultimate GPS
accuracy, in the range from centimeters to
millimeters.
Receiver clock error
The difference between GPS time and receiver
time.
Rover Dynamics
A linearized model of the rover motion/
acceleration. Rover dynamics constitutes the
stochastic process parts of the Kalman filter. It
propagates/extrapolates the solution from one
epoch to the next epoch.
RTK
See Real-time Kinematic.
RVP
Reverse Vector Processing, see RBP.