English
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About Almanac Files
When first using your MobileMapper CX, and because there is
no recent almanac file available yet in the unit, the internal
GPS receiver (or Mission Planning if used at that time) will use
a default almanac file stored in its protected memory.
After receiving GPS satellites for about 12 to 25 minutes, the
internal GPS receiver will be able to create a new almanac file.
This file will be stored in the “Windows” folder and named as
follows:
almyy.ddd
Where
alm
indicates this is an almanac file
yy
are the last two digits of the year (“07” for 2007)
ddd
in the file extension represents the Julian day number
(001 to 366).
You can also store your own almanac files in the “Windows”
folder using the same naming convention as the one described
above.
The internal GPS receiver and Mission planning will always
use the most recent almanac file stored in the Windows folder.
To force the use of a certain almanac file, rename this file (or
rename the others) so that it can be seen as the most recent
almanac. If you do that, don’t forget to rename the files after
use.
Choosing the Appropriate Real-Time Cor-
rection Age Limit
When selecting a DGPS mode, you have to set a parameter
called
Real-Time Correction Age Limit
. Here are a few recommen-
dations to help you set this parameter to the appropriate val-
ue.
The default value is 2 minutes. This is a good value to work
with in most cases. If for any reason, the reception of DGPS
corrections is of poor quality, you can increase this time limit
up to 10 minutes without significantly impairing the position
accuracy normally achieved with DGPS.
Summary of Contents for MobileMapper CX - Hiking GPS Receiver
Page 1: ...MobileMapper CX Getting Started Guide...
Page 8: ...English...
