CSI Wireless Seres, Reference Manual

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Seres Reference Manual
53
The Seres will reply with the following response:
$>
5.3.4 $JALT
This command turns altitude aiding on or off for the SX-1 GPS engine
inside the Seres. When set to on, altitude aiding uses a fixed altitude
instead of using one satellite’s observations to calculate the altitude. The
advantage of this feature, when operating in an application where a fixed
altitude is acceptable, is that the extra satellite’s observations can be used
to betterment of the latitude, longitude, and time offset calculations,
resulting in improved accuracy and integrity. Marine markets, for example,
may be well suited for use of this feature.
This command has the following layout:
$JALT,c,v[,GEOID] <CR><LF>
Where feature status variable, ‘c’, and threshold variable, ‘v’, may be one of
the following:
c Description
NEVER This is the default mode of operation where
altitude aiding is not used.
SOMETIMES Setting this feature to SOMETIMES allows the
receiver to use altitude aiding, dependent
upon the PDOP threshold, specified by ‘v’
ALWAYS Setting this feature to ALWAYS allows the
receiver to use altitude aiding regardless of a
variable. In this case, you may specify the
ellipsoidal altitude, ‘v’ that the receiver should
use. Optionally, if you specify the ‘,GEOID’
field, the receiver will use the GEOID as its
reference.
The Seres will reply with the following response: