Spectracom NetClock 9489 - Page 207

Upon completion of the GNSS survey the GNSS receiver will lock-in the calculated GNSS pos
ition and will enter Standard Mode. Once in Standard Mode, the GNSS survey will only be
performed again if:
the equipment will be relocated to another location and the receiver detects this (applies
to most Trimble receivers)
the Receiver Dynamics is set to Resurvey after every reboot (this feature is available only
with u-blox receivers and Trimble RES-SMT-GG receivers; it can be turned off, see "Set
ting GNSS Receiver Dynamics" on the next page.)
you manually delete the GNSS position, see "Deleting the GNSS Receiver Position" on
page197.
In the event that NetClock cannot complete a GNSS survey within 24hours (e.g., the survey pro
gress does not go beyond 99%), see "Single Satellite GNSS Receiver Mode" below.
Single Satellite GNSS Receiver Mode
The Single Satellite Mode is designed for use cases in which it is not possible for the GNSS
receiver to track at least four GNSS satellites for at least 33minutes continuously in a 12-hour
time window so as to complete the GNSS survey, i.e. obtain a 3-D fix. In such cases, NetClock
cannot operate in Standard Mode. This occurs frequently in areas with limited view of the sky
(e.g., "urban canyons").
In Single Satellite Mode, the GNSS receiver will be considered a valid input reference as long
as:
a.
the receiver was able to complete a survey during a time window with good satellite
reception, OR you have manually entered a valid position for your antenna location
(instructions can be found under "Manually Setting the GNSS Position" on page199
and "Determining Your Position" on page200.)
b.
the GNSS receiver continues to track at least one qualified satellite.
Note that NetClock is designed to provide the most accurate time in Standard Mode, hence the
Single Satellite Mode should only be used if the GNSS receiver could not complete a survey.
Note also that Single Satellite Mode can only be used if the NetClock unit remains stationary at
all times.
Mobile GNSS Receiver Mode
In Mobile Mode no surveys will be carried out since the position status is updated in near real-
time. NetClock will go into synchronization shortly after beginning to track satellites.
The Mobile Mode should only be selected if your NetClock unit will NOT remain stationary at
all times, i.e. instead of being operated in a building, it is installed in a mobile platform (such
as a vehicle, ship, plane, etc.).
3.3 Managing Input References
CHAPTER 3 • NetClock User Reference Guide Rev. 16
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