Leica MX400 Operating Instructions Manual page 122

DGPS
the 6 Channel GPS section above.
The Used Sats value indicates the number of satellites used in the
navigation filter to calculate your position as described in the 6
Channel GPS section above. In the 12 channel receivers,this value
is often between 5 and 9, sometimes 10, rarely 11, and probably
never at 12.
The Elevation Mask sets the lowest elevation at which a satellite
will be tracked. Satellites with an elevation below this number will
not be tracked, even if they are otherwise available to track. You
can set the elevation limit to any value up to 45° in the CFG1 GPS
screen. For most marine applications, the default limit of 5° is
appropriate. However, some applications may require a higher
elevation limit. Although not a marine environment, an example
would be trying to get the best possible position from the receiver in
an environment which has significant foliage causing low elevation
satellites to "pop in and out". You might choose to set the elevation
limit to 15° so that only satellites above the tree line are tracked.
Version 3.3
Operator's Manual
109