2. Tide
• The alternate rising and falling of the sea levels,
usually twice in each lunar day at a particular place,
due to the attraction of the moon and sun and the
rotation of the earth.
5. Effect of Tide on Bathymetry (Depth
Measurement)
• To account for the effect of tide on depth measurements (which
can be several meters), soundings are usually reduced to a
common reference level (or datum) such as mean sea level
(MSL), or the lowest astronomical tidal level (LAT).
6. QINSy
•
QINSy is a survey planning, acquisition, and real-time
hydrographic data processing solution, that supports a wide
variety of industries, from simple single beam surveys to complex
offshore construction works.
• Uses- Positioning and filtering
Allows multiple inputs (e.g. GPS, INS, tide, USBL, draft, etc.) for
real-time positioning in 2D and 3D
7.
8. QINSy
• Real-time processing
View processed point clouds, bathymetric grids, and side scan
sonar mosaics during their acquisition, for optimal QA/QC.
• Real-time displays
Navigation display (layers:ENC, DXF/DWG, Geotiff ECW)
multibeam displays, Numerics, profile display, and 3D
displays.
9.
10. Incorporating Tide In QINSy
• Detailed description on this can be found on the How To Articles on
QINSy.
If it's applied online, the tidal data will be stored in the databases.
Offline it can be applied in the Survey Manager, so the QPDs will be
updated with tidal information.
11. TIDE OPTIONS
1.Use GPS height as psuedo tide solution called RTK Tide. 'How-to
RTK Height as Tide'
2.Input data from a tide gauge (or multiple) that transmits data to the
vessel. Go to Tidegauge(s).
3.Using one or two manual gauges.
12. • 4. Use predicted tide using Admiralty Tide Table (ATT)
parameters. This is named Online prediction (ATT). (See
below.)
• 5. Input tidal information by creating a (predicted) tidal data
file. Go to Tidefile. (See below.)
• In the first four cases you will need to define a Tide Gauge
system in your Template database; for RTK tide you won't need
to.
13. Gauges at fixed positions/nodes
• When tide gauges or tide files are used it is necessary to
have Fixed Nodes defined in the Database Setup.
The fixed nodes give the positions of the gauges and the
correct height reference system to be used.
14. Using one or two manual gauges.
• This will be the demonstrated in todays seminar.
15. Manual Tide Gauge
A maximum of two gauges or files can be used for the online computation of the tide.
If more gauges are needed then the Tidal Processor in the Survey Manager should be
used instead of the online option.
When the Tide Gauge method is used with two tide gauges, the tidal value is
determined based upon a weighted distance from the gauges in the area between the
two tide gauges.
When outside this area only one tide gauge will be used.
•
16. Displays
• After setting up the tide priorities accordingly, the easiest
way to monitor them are by using the Alert Display.
