A-Gps - Spectracom VelaSync 1232 User Manual

3. Under
3.3.3.11 A-GPS
A-GPS stands for
tional data to the GNSS receiver by an alternative means of communication (e.g., via IP,
or by manual data entry), thereby reducing the time for the receiver to acquire and
track the actual satellite signals. This may lead to a significantly shorter time for
VelaSync to deliver a GNSS-based timing signal upon a "cold start" of the unit.
A-GPS client
The
ful in areas with poor GPS reception.
A-GNSS server
An A-GNSS server
ephemeris and almanac data to other client devices e.g., a Spectracom GSG-series
GNSS simulator.
Configuring A-GPS
To review or configure VelaSync's A-GPS settings:
CHAPTER 3 • VelaSync User's Manual Rev. 3
Identified Satellite Signal Strengths
bars: The letter in the tooltip window displayed for each signal bar indicates which
constellation the satellite belongs to:
Letter sym- GNSS Con-
bol stellation
G GPS
R GLONASS
E Galileo
J QZSS
C BeiDou
I IRNSS
The number next to the letter indicates the satellite number. The number below
indicates the signal strength (C/N
Assisted
A-GPS client is used to send assistance data to the GPS receiver. This is most use-
allows a VelaSync unit to operate as a server, thus providing A-GNSS
Caution: Do NOT use GLONASS when operating VelaSync as an A-
GNSS server, since this will likely crash the A-GNSS software.
hover with your cursor over the
).
o
GPS. This widely-used technology involves providing addi-
3.3 Managing References
143