Orolia Spectracom VelaSync 1232, Руководство пользователя

Страница: 155 / 268

constellation the satellite belongs to:
Letter symbol GNSS Constellation
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 additional
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 useful
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
•
VelaSync 1232 User Manual Rev. 4 143