Javad Maxor, Руководство оператора

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2-44 Maxor Operator’s Manual www.javad.com
C O N F I G U R A T I O N
Collecting Almanacs
2
Collecting Almanacs
Each satellite broadcasts a message (almanac) which gives the approximate
orbit for itself and all other satellites. If the receiver has an almanac, you can
considerably reduce the time needed to search for and lock on to satellite
signals.
The receiver regularly updates the almanac and stores the most recent almanac
in its Non-Volatile Random Access Memory (NVRAM).
1.
Set up the receiver (connect the external antenna if needed) in a location
with a clear view of the sky.
2.
Turn on the receiver. Wait for about 15 minutes while the receiver collects
almanac data from satellites.
Notice: If 15 minutes have passed and the receiver does not lock
on to satellites, you may need to clear the NVRAM. See
“Clearing the NVRAM” on page 4-17 for this procedure.
You will need to collect or update the almanac:
• If the receiver has been off for a long time.
• If the last known receiver position, stored in the NVRAM, is different from
the present position by a few hundred kilometers at least.
• After loading a new OAF.
• After loading new firmware.
• After clearing the NVRAM.
• Before measuring.
The collection and/or update of an almanac can take as long as 15 minutes.