Extract Depths (Bathymetry)
Summary
Extracts depth point features from a surface created within the Compose Surface window in ArcGIS for Maritime: Bathymetry. Depths features are points sampled from an interpolated surface, a Bathymetric Attributed Grid (BAG).
Depths represent a measurement of the vertical distance from a given water level to the seafloor.
A BAG is a multidimensional hydrographic data file that models elevation and Total Propagated Uncertainty (TPU) values in a gridded format. It conforms to standards created by the Open Navigation Surface Working Group.
Usage
Use this tool to create data for use with the Depths to ASCII tools.
The BIS Model parameter consists of a mosaic dataset, attributes, display order, and sorting rules. You create and save BIS models in the Compose Surface window in ArcGIS for Maritime: Bathymetry.
The Clipping Feature parameter requires one feature. This can be a single selected feature or a feature layer with a definition query that references one feature. If Clipping Feature is a path to a feature class, that feature class must contain one polygon.
The Depths Feature parameter is the location in which the new output feature class will be generated.
Legacy:Prior to 10.1 Service Pack 1, this parameter expected an existing, Z enabled feature class with certain fields already defined.
Depth and TPU values are sampled from the elevation and uncertainty bands in the BAG dataset. Depth values will be stored as part of each point's geometry, such that the output will be z-enabled, while TPU values will be added to the attribute table.
Syntax
| Parameter | Explanation | Data Type |
bis_workspace |
The Bathymetric Information System (BIS) geodatabase (.gdb) or a connection (.sde) to the BIS database containing the surface model and mosaic dataset. | Workspace |
bis_model_name [bis_model_name,...] |
The name of the composite surface in the BIS Workspace. It is prepopulated with a list of names of the models saved in the workspace. | String |
clip_layer |
A feature layer that contains a single polygon clipping feature which defines the feature extraction extent. | Feature Layer |
spacing_value |
The desired spacing between sampled points in the output, in meters. | Double |
depths_layer |
The feature class that will contain the extracted depths features. This tool will output a new, z-enabled point feature class. | Feature Class |
Code Sample
The following stand-alone script demonstrates how to use the ExtractDepths tool.
# Name: ExtractDepths_Example.py
# Description: Extracts point features from a BIS composite surface.
# Requirements: ArcGIS for Maritime Bathymetry
import arcpy
# setup parameters
bisWorkspace = "C:/data/BIS.gdb"
bisModelName = "NewModel"
clipLayer = "C:/data/MyData.gdb/ClipPolyFC"
spacingValue = 50.0
soundingsLayer = "C:/output/Output.gdb/PointFC"
# execute the tool. For a stand-alone scripts, checkout the extension first - arcpy.CheckOutExtension("nauticalb")
arcpy.ExtractDepths_bathymetry(bisWorkspace, bisModelName, clipLayer, spacingValue, soundingsLayer)