TSHD - Tide | qpssoftware

Tide System Definition

In case you are not using a positioning system with an 'accurate' height status, you may need to define a Tide System as follows:

image2016-1-29 10:37:46.png 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.

image2016-1-29 10:41:50.png Enter an appropriate name that provides instant recognition in Online displays of what and where it is.

image2016-1-29 10:42:47.png Select Tide Gauge System from the drop down list.

image2016-1-29 10:48:25.png Select the appropriate driver that will decode the tide messages sent to the software.

The driver list includes both serial and network drivers. If you have already defined other systems and some of the data messages are sent by the dredger's PLC, it is likely that tide data will also be issued by the PLC.

image2016-1-29 10:49:55.png Enter interface port parameters.

Please refer to A Note on Interfacing Parameters.

image2016-1-29 11:3:27.png Enter the data update parameters. Depending on the driver selected one or other, or both, these parameters are shown:

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 motion sensor system may for example output values hundreds of times per second, where twenty times per second is sufficient. In this case, enter a value of 0.05s. 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 motion sensor 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 motion sensor systems will exhibit no latency, or will have compensated for the latency in the time tag of each data message.

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 motion sensor system may for example output values hundreds of times per second, where twenty times per second is sufficient. In this case, enter a value of 0.05s. 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 motion sensor 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 motion sensor systems will exhibit no latency, or will have compensated for the latency in the time tag of each data message.

image2016-1-29 11:3:53.png Press Next to advance to the second page of the wizard which will look like this:

image2016-1-29 12:2:35.png Initially the dialog is empty. Clicking Add Tide opens the Select Nodes dialog in which any previously defined Tide Gauge fixed nodes are listed.

image2016-1-29 12:6:23.png Select one of the listed fixed nodes and click OK.

image2016-1-29 12:7:42.png If none are listed or another must be added click on which opens the Edit Node Parameters dialog.

image2016-1-29 12:11:22.png Enter all the parameter values associated with the tide gauge node.

Node
Name	Enter a name for the node.
Node Position
Latitude / Easting	Enter the latitude or easting coordinate.
Longitude / Northing	Enter the longitude or northing coordinate.
Horizontal Datum	Select a datum from the pull down menu. Usually coordinates are given on the survey datum.
Node height
Station Height	Enter the station height above the vertical datum.
Instrument Height	Enter the instrument height above the station height.
Vertical Datum	Select the vertical datum. The options are identical to those in the Mean Water Level Model defined in the Geodetic set up.
Height Level	Correction to the vertical datum. The options are identical to those in the Mean water level model.
Height Offset	Enter a fixed height offset relative to the vertical datum if needed.

The Add Generic button in the Tide Gauge Observation Parameters dialog refers to:

image2016-1-29 12:40:45.png If the tide value in the data message has an associated identifier (slot id) click on Edit Slot and enter the numeric, alphabetic or alphanumeric identifier.

Make sure the slot entry is exactly the same as the data message identifier or the tide will not be decoded. Click OK.

image2016-1-29 12:46:24.png On the third and last page of the wizard enter all the observation parameters for each observation listed on the left.

Observation parameters
Name	Enter a descriptive name for the observation.
Unit	Select the appropriate observation unit. In some cases there will only be one choice.
a-priori SD	Enter the SD for each observation in turn.
Fixed C-O	Constant correction to the parameter value.
Variable C-O	Variable correction to the parameter value.
Scale factor	Use scale factor to convert the raw output to units in the Acquisition Software. For example if local output is in centimeters, then enter scale factor 0.01 here to convert to meters.
Apply C-Os offsets first	C-Os are added or subtracted before a scale factor is applied.
Apply Scale factor first	Scale factor is applied before C-Os are applied.
Apply automatically	The order in which corrections are applied is done in the software.

image2016-1-29 13:1:13.png Click Finish to complete the Tide system definition.

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