Derived Geometry (Aeronautical)
The Aeronautical Information Exchange Model (AIXM) Importer will create a null geometry for an airspace feature if AIXM messages contain instructions to generate derived airspace geometries. This tool updates the null geometry with a polygon derived from other airspace features.
Polygon construction begins with a starting feature, called the base airspace. The tool unions, intersects, or subtracts additional features, called component airspace, to the base airspace. AIXM version 4.5 or 5.1 messages supply the information used in generating the new polygon.
AIXM messages identify the base and component airspaces. Base and component airspaces exist in a one-to-many relationship.
Geometric operators, listed in an order of operations, control how the base and component airspaces are combined. AIXM messages can use the following operators:
- Copy the same extent of existing geometries.
AIXM messages provide a number sequence for the order of operations against the base and component airspaces.
If AIXM messages reference a base or component feature that is missing in the database, the tool will not create the derived geometry.
A connection file specifies the Input Workspace (input_workspace). The new polygon airspace is created in the version identified in the connection file. Make sure you have connected to the correct version before running the tool.
This tool can only run on databases with the ESRI Aeronautical Solution 10.0 Service Pack 1 or newer AIS schema.
The workspace that contains the AIXM data.
An SQL expression used to select a subset of features. The syntax for the expression differs slightly depending on the data source. For example, if you're querying file or ArcSDE geodatabases, shapefiles, or coverages, enclose field names in double quotes:
If you're querying personal geodatabases, enclose fields in square brackets:
In Python, strings are enclosed in matching single or double quotes. To create a string that contains quotes (as is common with a WHERE clause in SQL expressions), you can escape the quotes (using a backslash) or triple quote the string. For example, if the intended WHERE clause is
"CITY_NAME" = 'Chicago'
you could enclose the entire string in double quotes, then escape the interior double quotes like this:
" \"CITY_NAME\" = 'Chicago' "
Or you could enclose the entire string in single quotes, then escape the interior single quotes like this:
' "CITY_NAME" = \'Chicago\' '
Or you could enclose the entire string in triple quotes without escaping:
""" "CITY_NAME" = 'Chicago' """
For more information on SQL syntax and how it differs between data sources, see the help topic SQL reference for query expressions used in ArcGIS.
The following Python window script imports the Aeronautical toolbox and executes the DerivedGeometry function.
arcpy.ImportToolbox(r'C:\Program Files\ArcGIS\Desktop10.0\ArcToolbox\Toolboxes\Aeronautical Tools.tbx') arcpy.DerivedGeometry_Aeronautical("Database Connections\\your_sqlexpress_ASP_PD.sde")