Vector Sensor Reference Manual
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1.8.16
$HEHDT Message
This message provides true heading of the vessel. This is the direction that the vessel (Vector
Antenna Array) is pointing and is not necessarily the direction of vessel motion (the course over
ground), although they may be the same.
The COG measurement in the $GPVTG message describes the true direction of travel of the boat
as a result of the vessel trust, currents, wind, etc. Please note that the COG measure is derived
from the primary GPS receiver only and is less accurate than the true heading derived using the
RTK solution that uses both GPS receivers.
The $HEHDT message output rate may be configured with the following command.
$JASC,HEHDT,rate<CR><LF>
Where ‘rate’ may be any of the following values expressed in Hz: 0, 1, 5, 10, or 0.2.
The output from the $JSHOW<CR><LF> command provides the current output rate setting for
this message.
The details of this command and the $HEHDT are described in Chapter 6.
1.8.17
$HEROT Message
This message provides rate of turn of the vessel and has units of degrees per second.
The $HEHDT message output rate may be configured with the following command.
$JASC,HEROT,rate<CR><LF>
Where ‘rate’ may be any of the following values expressed in Hz: 0, 1, 5, 10, or 0.2.
The output from the $JSHOW<CR><LF> command provides the current output rate setting for
this message.
The details of this command and the $HEROT message are described in Chapter 6.
1.8.18
Proprietary $PSAT,INTLT Message
The $PSAT,INTLT data message is a proprietary NMEA sentence that provides the tilt
measurement from the internal inclinometer, in degrees. This message can be output only at 1 Hz
is turned on using the following command.
$JASC,INTLT,1<CR><LF>
To turn this message off, use the following command.
$JASC,INTLT,0<CR><LF>
The details of this command and the $PSAT,INTLT message are described in Chapter 6.
