Product specifications

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constant is 0.5 seconds of smoothing. Increasing the time constant will increase the
level of pitch smoothing.
The following command is used to adjust the pitch time constant.
$JATT,PTAU,ptau<CR><LF>
Where ‘ptau’ is the new time constant that falls within the range of 0.0 to 3600.0
seconds.
Depending on the expected dynamics of the vessel, you may wish to adjust this
parameter. For instance, if the vessel is very large and is not able to pitch quickly,
increasing this time is reasonable. The resulting pitch would have reduced ‘noise’,
resulting in consistent values with time. However, artificially increasing this value
such that it does not agree with a more dynamic vessel could create a lag in the
pitch measurement. A convenient formula for determining what the level of
smoothing follows. If you are unsure on how to set this value, it’s best to be
conservative and leave it at the default setting.
ptau (in seconds) = 10 / maximum rate of pitch (in °/s)
You may query the Crescent Vector OEM for the current pitch time constant by
issuing the same command without an argument.
$JATT,PTAU<CR><LF>
Note: If you are unsure of the best value for this setting, it’s best to be
conservative and leave it at the default setting of 0.5 seconds.
$JATT,HRTAU
The heading rate time constant allows you to adjust the level of responsiveness of
the rate of heading change measurement provided in the $HEROT message. The
default value of this constant is 2.0 seconds of smoothing. Increasing the time
constant will increase the level of heading smoothing.
The following command is used to adjust the heading time constant.
$JATT,HRTAU,hrtau<CR><LF>
Where ‘hrtau’ is the new time constant that falls within the range of 0.0 to 3600.0
seconds.
Depending on the expected dynamics of the vessel, you may wish to adjust this
parameter. For instance, if the vessel is very large and is not able to turn quickly,
increasing this time is reasonable. The resulting heading would have reduced ‘noise’,
resulting in consistent values with time. However, artificially increasing this value
such that it does not agree with a more dynamic vessel could create a lag in the rate
of heading change measurement with higher rates of turn. A convenient formula for
determining what the level of smoothing follows. If you are unsure on how to set
this value, it’s best to be conservative and leave it at the default setting.
hrtau (in seconds) = 10 / maximum rate of the rate of turn (in °/s2)