We are trying to derive bathymetry using sentinel images using QGis 2.18. The training data is from a boat gps track taken in 2 days. The depth value captured needs to be corrected for tidal influences. The track has attributes on date and time, position and depth (sonar).

What is the best way to do it?

Is there any formula or free software to correct the data to obtain the mean lower low water needed for the chart?

The image shows real color in ground and relative bathymetry at sea. The dots are from the Boat gps track

closed as unclear what you're asking by ahmadhanb, BERA, Spacedman, whyzar, Mark Ireland Jan 29 at 14:13

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • This is a bit of a broad, unclear question. You could improve it by: showing a typical Sentinel image that you are working with; explain a bit more about the boat tracking data and its relationship to the tide; showing what the track data looks like; comparing it with existing bathymetry data. – Spacedman Jan 29 at 10:13
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    The questions doesn't really have anything to do with Sentinel imagery. What is being asked is "How to correct echosounder measurements to 'mean lower low water'?". – Mikkel Lydholm Rasmussen Jan 29 at 11:04
  • Most likely you will have to write a trigger function that will automatically increase or decrease the depth values based on the wave height data, but this is a solution for the DBMS ... – Cyril Jan 30 at 10:12