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. See Surface Filter (Subset of a Reference Surface). 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.

Related commands:

Hypotheses Cleaning

Procedure

To edit hypotheses in Subset Editor:

1. Open a CUBE surface.

2. Select the Subset Editor command.

3. Define the subset with a bounding box.

4. Load the subset.

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

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

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

7. Click Load to view the CUBE surface.

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

Some nodes have alternative hypotheses that were not selected during disambiguation You can view alternative hypotheses and compare them against the selected ones. If needed, the alternative hypotheses can be nominated to replace the established hypotheses. See Alternative Hypotheses for the different views of alternative hypotheses.

To replace an hypothesis:

1. Select an alternative hypotheses display option in the Subset Control window, for example, Show Alternative Hypotheses.

2. Select an alternative hypothesis in the 2D or 3D window.

3. Select the Nominate command.

The selected hypothesis is now highlighted in blue, indicating it has replaced the original hypothesis.

All nominated hypotheses are given the highest confidence value of 0.0.)

4. Select the Save command to save your data.

5. To remove the nomination flag, select the Clear command.