Hypothesis Editing

CUBE surfaces can be displayed in the Subset Editor for examination and editing, using an iterative process to choose which of multiple hypotheses of depth values are the best ones to represent the sea floor.

When a CUBE surface is created, soundings are weighted and contribute to surface grid nodes based on TPU values and distance from the nodes. The CUBE surface allows for multiple depth estimates or hypotheses to exist at a single grid node, depending on the variation of the sounding data. CUBE then uses “Disambiguation” to determine which hypothesis at each node is the most “correct”.

You can verify and, if necessary, override, a CUBE decision in Subset Editor, by nominating an alternative hypothesis as the depth. Once these kinds of changes have been made to the CUBE surface, the surface is updated.

A surface filter can then be applied to the data. Any sounding data that is not in agreement with the selected hypotheses will be flagged as rejected. By applying this surface filtering, the number of manual edits required by the hydrographer to produce a clean sounding data set is greatly reduced.

To examine an open CUBE surface in Subset Editor:

1. Select the Subset Editor command.

2. Define the subset with a bounding box.

3. Load the subset.

Data contained within the bounding box is loaded into the 3D Subset view.

4. In the Subset Control window, select the CUBE Hypothesis layer.

5. Expand the Select Surface data tree and select a surface containing CUBE data.

6. Click Load to view the CUBE surface.

7. To return to the normal display in the 3D and 2D Views, click Unload.

The display options for the hypotheses are listed at the bottom of the Subset Control window.

Wire frame Hypotheses

Fixed Size Hypotheses

Nominate Alternative Hypotheses

Show only Selected Alternatives

Show Only Hypotheses with Alternatives

8. View and edit the hypotheses. See Hypotheses Cleaning

9. Update the surface. See Recompute Surface