Generate depth areas

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Depth areas are geographic features used to depict depth ranges between contours in S-57- and S-100-based products. The Generate Depth Areas tool uses a triangulated irregular network (TIN) and contour lines as inputs for creating and attributing depth polygons. The source for the TIN can be point data, in which the point spacing can be irregular, or raster data, in which the point spacing can be regularly gridded.

Before generating the depth areas, consider the following:

• It is recommended that the contours be appended to the DepthsL feature class in the Nautical workspace with the S-57 schema. The data can be appended using the Copy S-57 Features tool.
• The compilation scale value should be verified, and updated if necessary, before running the tool.
• For better performance, it is recommended that you generate depth areas for an extent corresponding to S-57 cell sizes.

Ensure that you have prepared the data you want to use for generating depth areas. Once you have prepared the TIN and created depth contours, follow the steps below to generate depth areas:

1. If necessary, create an ArcGIS Maritime database schema and add data from the Nautical feature dataset to the Contents pane.
   • The Maritime S-57 tab appears.
2. On the Maritime S-57 tab, in the S-57 Editing group, click the Compilation Scale drop-down arrow and choose a scale.
3. In the Geoprocessing pane, expand Maritime Tools > Data Management and click Generate Depth Areas .
4. Set the parameters as follows:
   1. For the Input TIN parameter, choose the TIN dataset that was used to generate the depth contours.
   2. For the Input Contour Features parameter, choose the layer (such as DepthsL) containing the depth contours that were generated from the TIN.
   3. For the Depths Field parameter, verify that the value is set to VALDCO.
   4. For the Depth Direction parameter, choose the direction based on the depth data.
   5. Optionally, in the Extent Polygon Features parameter, indicate the features where you want the depth area polygons to be generated.

      Features, such as the M_QUAL polygon or product coverage AOI, can be used in the Extent Polygon Features parameter. If none are specified, the TIN domain will be used. The TIN domain is a polygon feature representing the interpolation zone of the TIN dataset.

   6. Set the Target Workspace parameter to the geodatabase where you want the depth areas to be generated.

      Hinweis:

      This database must contain the S-57 schema.

   7. Type values for the Minimum Depth and Maximum Depth parameters.

      The minimum depth value is used to populate the minimum depth of polygons that are shallower than the shallowest contour value. The maximum depth value is used to populate the maximum depth value of polygons that are deeper than the deepest contour value.

5. Click Run to generate the depth areas.

   The depth area polygons are generated and added to the geodatabase.

   Hinweis:

   The resulting depth area features may contain attribute values where DRAVL1 equals DRVAL2. This is a result of cases where there are isolated contours and no additional vertices within to discern shoal and deep. These features should be inspected manually and attributed accordingly.

Regardless of the input depth direction, the tool populates the output depth fields (DRVAL1, DRVAL2) as positive with drying heights as negative. If the TIN and depth contours had the positive up depth direction, use the Calculate Field tool on the DepthsL layer to convert the depth values to positive values, as required by the S-57 specification. This can be done by multiplying the value of the depth contour (VALDCO) by (-1).

Validate the generated depth data using the S-58 Error Manager to verify that the output does not contain S-58 errors. For guidance on resolving any remaining topological issues, refer to solutions for topology errors.