Spectracom VelaSync 1225, Руководство пользователя

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3.3.3.9 Manually Setting the GNSS Position
Note: This topic applies only to stationary applications , i.e. to Stand-
ard mode, or Single Satellite mode.
The exact geographic position (location and elevation) of the antenna your VelaSync
unit—and thus its onboard GNSS receiver—is a major factor for VelaSync to calculate an
accurate System Time from the GNSS reference.
Note: The elevation (altitude) should be set in accordance with the
World Geodetic System 1984 ( WGS 84 ), not Mean Sea Level (MSL).
Normally, the onboard GNSS receiver will track and adjust the antenna position during
the so-called GNSS
self survey , which is performed during initial commissioning of a
VelaSync unit, or when rebooting a unit after it had been powered down for some time
("cold start").
Depending on where your GNSS antenna is installed and thus, how good the reception
is, the self survey may be adequate for most applications.
Setting a Manual Position , however, i.e. manually applying your current geographic pos-
ition data (Latitude, Longitude, and Altitude) may be necessary if your GNSS receiver
could not complete its survey due to poor reception.
In some cases, setting the position manually may also help to reduce the amount of time
needed for the initial position "fix", i.e. for VelaSync to synchronize with the satellites in
view.
Note that this position will also be used if Apply A-GPS Data is checked.
To manually set your position:
1.
Determine your geographic position. For more information, see "Determining
Your Position" on the facing page .
2.
Navigate to INTERFACES > REFERENCES: GNSS 0 . In the GNSS 0 status win-
dow, click Edit in the lower left corner. The GNSS 0 window will open:
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CHAPTER
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VelaSync User's Manual Rev. 3
3.3 Managing References