ashtech DG14, Reference Manual

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Receiver Commands 153
Receiver Commands
SEM: Secondary Elevation Mask
$PASHS,SEM,d1,d2,d3
This command sets a secondary elevation mask angle value for a sector of the sky
defined by two azimuth angles. The second sector is the region between the first
and second azimuths measured clockwise from North. d1 is the secondary elevation
mask angle. d2 is the first azimuth defining the second sector. d3 is the second
azimuth defining the secondary sector.
When you send the SEM command, it overrides any previously existing values.
PEM commands issued after the SEM command change the elevation mask for
only the primary PEM zone. The previously issued SEM setting continues in effect.
To apply PEM to the whole sky, you must disable the SEM.
Example
Enter the following commands to set the mask zone in Figure 4.7.
$PASHS,PEM 10
$PASHS,SEM,20,300,60
—OR—
$PASHS,PEM 20
$PASHS,SEM,10,60,300
DEFAULT SETTING
SEM— OFF
Figure 4.7. SEM Mask Zone
PEM=10
PEM=20
N
60
o
300
o