TSHD - Gyro

Gyro System Definition

Add a new system by selecting “Edit” from the menu bar, and then “New” and “System”, or right click on the item System in the item tree.

The following dialog opens. It is the first page of a wizard that steps you through the system definition process.

Enter an appropriate name that provides instant recognition in Online displays.

Select Gyro Compass from the drop down list.

From the drop down list select the driver that corresponds to the data message output by the gyro system to which QINSy is interfaced.

Note that the interfacing can be either serial or network so make sure to select the correct type.

Enter interface port parameters.

Please refer to A Note on Interfacing Parameters.

Enter the update parameters.

Updates

Maximum update rate

Enter a value to determine how often data will be decoded by the interface driver. Some equipment is capable of outputting data at high output rates, but it may not be necessary to use each update. A gyro system may for example output values tens of times per second, where 10 times per second is sufficient. In this case, enter a value of 0.10s. Any data not decoded by the driver is lost and cannot be recovered later.

Latency

Latency is the time between the actual measurement made in the gyro system and the time the data message arrives at the port. The time in QINSy will thus be the arrival time corrected with the latency.
Modern gyro systems will exhibit no latency, or will have compensated for the latency in the time tag of each data message.

Press Next to advance to the second page of the wizard which will look like this:

Enter the gyro observation parameters - see table below.

Observation Parameters
Name	Enter a name for the gyro.
Location	Select the object the gyro is located on. No offsets are required for a heading system. The heading is applied as input into a rotation matrix. If you have been following this Howto step by step there will be several objects in the drop down list. Typically the gyro is on the pontoon.
Type	Select Bearing (True), only option.
Unit	Select the type of units the gyro is outputting. Options are: Degrees, Grads, Radians, Arc Minutes, Arc Seconds. In case the unit is not obvious check the settings in the gyro itself.
A-priori SD	Enter the a-priori SD value of the gyro. Usually the default value is acceptable.
Fixed C-O	Enter fixed C-O correction. Fixed (C-O) corrections do not vary over time or location and must be recorded in the same measurement unit as the observation they refer to.
Variable C-O	Enter Variable C-O. The value for the Calculated minus Observed correction you enter will be added to the raw observation value. The C-O correction is related to systematic minor deviations of the measurements. Variable (C-O) corrections are determined by calibration. They may be instrument specific and/or time/location dependent.
Scale factor	The Scale Factor or Calculated divided by Observed correction should correct the raw observation measurement unit to the standard measurement unit. When no Scale factor is needed, leave it at 1.0
Slot Identifiers
Slot Number 1/2	This parameter is applicable to a 'cloned gyro' which is frequently encountered in dredging operations. Typically the pontoon heading is 'cloned' to the ladder as explained in the section on Cloned Gyro. A slot number/identification is assigned when defining the cloned heading which is selected here.

Click Finish to complete the system definition.

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