Spectracom VelaSync 1225, Руководство пользователя

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3.
Under Identified Satellite Signal Strengths hover with your cursor over the
bars: The letter in the tooltip window displayed for each signal bar indicates which
constellation the satellite belongs to:
Letter sym-
bol
GNSS Con-
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
o
).
3.3.3.11 A-GPS
A-GPS stands for Assisted GPS . This widely-used technology involves providing addi-
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 A-GPS client is used to send assistance data to the GPS receiver. This is most use-
ful in areas with poor GPS reception.
A-GNSS server
An A-GNSS server allows a VelaSync unit to operate as a server, thus providing A-GNSS
ephemeris and almanac data to other client devices e.g., a Spectracom GSG-series
GNSS simulator.
Caution: Do NOT use GLONASS when operating VelaSync as an A-
GNSS server, since this will likely crash the A-GNSS software.
Configuring A-GPS
To review or configure VelaSync's A-GPS settings:
3.3 Managing References
CHAPTER
3
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VelaSync User's Manual Rev. 3 143