Spectracom VelaSync 1225, Руководство пользователя

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Table 3-2:
Receiver dynamics, ~modes, ~ dynamics, ~ types
Receiver Mode
Receiver Dynamics
Land
(Resurvey)
Sea Air
Stationary
(No Resurvey)
Single Satellite irrelevant irrelevant irrelevant irrelevant
Standard
Mobile (with u-blox receivers)
Notes:
The u-blox M8T receiver now uses Land to indicate it will RESURVEY on reboot,
and Stationary to indicate it will not resurvey after reboot.
3.3.3.5 Performing a GNSS Receiver Survey
Note: This topic only applies to stationary applications – in Mobile
receiver mode NO surveys will be carried out since the position is
updated continuously.
When VelaSync's integrated GNSS receiver performs a survey, it tries to determine or
verify its geographic position with high accuracy. An accurate geographic position is
required to calculate a precise system time from the GNSS reference.
During a GNSS survey, the position will be iteratively recalculated while gradually increas-
ing the position accuracy. A survey can take up to 33 minutes, but typically VelaSync will
synchronize earlier, i.e. offer a valid Time and 1PPS reference, once it has obtained a suf-
ficiently accurate preliminary position.
Note: If a system has been moved, in Standard receiver mode and Land
Dynamics , receivers will automatically re-survey on reboot. In Stand-
ard mode and Stationary Dynamics , the unit will survey only once, and
will not re-survey on reboot.
Verifying GNSS Survey Progress
To see if VelaSync's GNSS receiver is performing a survey and if so, verify its progress:
3.3 Managing References
CHAPTER
3
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VelaSync User's Manual Rev. 3 133