Product specifications

Where ‘tau’ is the new time constant that falls within the range of 0.0 to 200.0

seconds.

The setting of this value depends upon the expected dynamics of the receiver. If the

Crescent will be in a highly dynamic environment, this value should be set to a lower

value since the filtering window would be shorter, resulting in a more responsive

measurement. However, if the receiver will be in a largely static environment, this

value can be increased to reduce measurement noise. The following formula

provides some guidance on how to set this value initially, however, we recommend

that you test how the revised value works in practice. If you are unsure what is the

best value for this setting, it’s best to be conservative and leave it at the default

setting.

tau (in seconds) = 10 / maximum acceleration (in m/s2)

You may query the Crescent for the current speed time constant by issuing the same

command without an argument.

$JTAU,SPEED<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 0.0 seconds.

$JATT,HBIAS

You may adjust the heading output from the Crescent Vector in order to calibrate the

true heading of the Antenna Array to reflect the true heading of the vessel using the

following command.

$JATT,HBIAS,x<CR><LF>

Where x is a bias that will be added to the Crescent Vector’s heading, in degrees.

The acceptable range for the heading bias is -180.0° to 180.0°. The default value of

this feature is 0.0°.

To determine what the current heading compensation angle is, send the following

message to the Crescent Vector.

$JATT,HBIAS<CR><LF>

$JATT,PBIAS

You may adjust the pitch / roll output from the Crescent Vector in order to calibrate

the measurement if the Antenna Array is not installed in a horizontal plane. The

following NMEA message allows to you to calibrate the pitch / roll reading from the

Crescent Vector.

$JATT,PBIAS,x<CR><LF>

Where x is a bias that will be added to the Crescent Vector’s pitch / roll measure, in

degrees. The acceptable range for the pitch bias is -15.0° to 15.0°. The default

value of this feature is 0.0°.