AIXM 5.x Reader Parameters

Application Schema

AIXM Schema Selection

This parameter determines how the AIXM v5 schemas are identified. The following options available:

  • Dataset (default) – The schemas are identified through the dataset's xsi:schemaLocation attribute.
  • http://www.aixm.aero/schema/5.1.1/message – The schemas and their dependent XSD documents are identified by this URI.
  • http://www.aixm.aero/schema/5.1/message – The schemas and their dependent XSD documents are identified by this URI.
  • Other – The schemas can be specified using the Application Schema and/or xsi:schemaLocation parameters as outlined below.

This optional parameter specifies Application Schemas through .xsd files.

This optional parameter specifies the location of the XSD Schema documents via whitespace-separated namespace-URI and xsd-location-URL pairs, following the same syntax as the xsi:schemaLocation attribute.

Settings

The legal values for this parameter are white-space-separated XML namespace declarations as they would appear in an XML element.

This parameter allows different namespace declarations to be used, other than the ones extracted from the parsed XSD documents.

The FME feature type and/or attribute names may include the XML Namespace prefixes used in the XSD schemas. The prefix will be separated from the names by an underscore.

By default, the prefixes are not added to the names.

  • Feature Types – Includes the prefixes in the feature types. Setting this parameter to Feature Types is necessary if the XSD Schema contains feature types with the same name in different namespaces.
  • Feature Types and Attributes – Includes the prefixes in both the feature types and attributes.

Specifies whether GML properties that are mapped as XML fragments should be converted into XML documents.

The conversion will add missing namespace declarations to the fragments, maintain CDATA sections, and prefix an XML header declaration to the fragment. Converting the XML fragments into XML documents allows XML-based parsers (for example, XSLT and XQuery-based processors) to further process the fragments.

Specifies whether GML properties that are mapped as XML fragments should be flattened into nested attributes.

Note  The flattening will only be applied to the data features carrying the XML fragments, so the new flattened nested attributes will not be reflected in the FME feature type schema definitions.

Determines whether the reader should validate the specified dataset against the XSD schema.

Geometry Parameters

This parameter specifies whether the AIXM v5 geometric properties should be represented as attributes in the FME feature type definitions.

  • Yes (default) – The feature type definitions will contain the geometry names as attributes, and their type is set to xml_geometry. If an attribute X has its type set to xml_geometry, this attribute X becomes a placeholder in the feature type definition. It is a placeholder because actual data features for the feature type definitions will not have this attribute; instead, the data features will have a geometry named “X”.
  • No – The feature type definition will not contain geometry names.

Overrides the axis order when reading coordinate tuples in an AIXM v5 <pos> or <posList> element.

Valid values: 1,2, 2,1, 1,2,3, and 2,1,3

When this parameter is selected, the reader, in addition to mapping the GML geometry XML elements into FME geometries, will include these elements in FME attributes as XML fragments in the feature.

The FME geometry attributes are typed as xml_geometry in the feature type definition.

Tip  This parameter is useful in case of a GML geometry reading error, since the XML fragment representing the GML geometry will also be carried along in the same feature as an attribute.

Controls how segments in a path are joined together when the segments' end points are not connected:

  • Inserting New Line connects the path by inserting a new connecting line between the original segments.
  • Snapping End Points forces the first point of each segment to equal the last point of the previous segment.

Specifies whether the points in the <gml:GeodesicString> are interpolated along geodesic curves.

The number of interpolation points is determined by the selected Interpolation Method, and their exact locations are calculated using either the Vincenty or the Destination Point Interpolation Formula.

This parameter is enabled (set to Yes) by default.

Specifies the formula used to calculate the position of interpolation points along a geodesic. This setting determines the mathematical approach for determining point locations based on the underlying Earth model.

  • Ellipsoidal (Vincenty) (default) – Uses the Vincenty formula, which is based on an ellipsoidal Earth model. This method provides highly accurate interpolation point locations by accounting for the Earth's flattening and the variations in distance caused by its elliptical shape.
  • Spherical (Destination Point) – Uses a spherical model of the Earth, approximating it as a perfect sphere. This method calculates interpolation points using the Destination Point formula, which determines the position of a point along a great circle given a starting point, azimuth (bearing), and distance. It is less precise but faster and simpler for interpolation calculations.

Specifies how the number of interpolation points are calculated between geodesic control points:

  • Logarithmic (default) – The number of interpolation points added increases as the distance between geodesic control points grows. However, this increase happens at a gradually decreasing rate, following a logarithmic reduction function. This results in relatively more points over larger distances compared to an exponential reduction.
  • Exponential – The number of interpolation points added increases as the distance between geodesic control points grows, but at a rapidly decreasing rate. This decrease follows the steep curve of an exponential reduction function, resulting in far fewer points compared to a logarithmic reduction over the same distance.
  • Fixed Distance – The number of interpolation points added is directly proportional to the total distance between geodesic control points. Interpolation points are added at regular intervals, determined by the specified Interval Distance.

Specifies the minimum distance, in kilometers, beyond which interpolation starts; no interpolation points are added if the distance between control points is less than or equal to the threshold. The number of points added are based on the Interpolation Method.

Valid Values: Any positive real number representing the number of kilometers

Default:  20

Note  This parameter is only applicable when Interpolation Method is set to Logarithmic or Exponential.

Scales the number of interpolation points directly relative to the maximum calculated by the selected Logarithmic and Exponential interpolation methods. The parameter adjusts how many interpolation points are added for a given distance.

Valid Range: 0.01 to 1.0

Default: 0.1

Higher values (for example, 1.0) add the maximum number of points calculated by the interpolation method for the distance; lower values (for example, 0.01) reduce the number of points proportionally, adding fewer points for the same distance.

Note  If this parameter is left blank, the default value will be used.
Note  This parameter is only applicable when Interpolation Method is set to Logarithmic or Exponential.

Determines how the number of interpolation points decreases as the distance between geodesic control points increases in the Logarithmic and Exponential interpolation methods.

Valid Range: >0 to 100

Default: 1

Higher values decrease the number of points more rapidly, resulting in fewer points for longer distances; lower values decrease the number of points more gradually, resulting in relatively more points for longer distances.

Note  If this parameter is left blank, the default value will be used.
Note  This parameter is only applicable when Interpolation Method is set to Fixed Distance.

Specifies the fixed distance, in kilometers, between interpolation points for the Fixed Distance interpolation method. The parameter sets the interval at which points are added along the geodesic.

Valid Values: Any positive real number representing the number of kilometers.

Default: 0.5 * T, where T is the Interpolation Threshold.

Note  If this parameter is left blank, the default value will be used.
  • Yes (default) – Splits the interpolation of the <gml:GeodesicString> element into multiple curve segments, with each segment starting and ending at control points. This is useful for <gml:GeodesicString> elements with more than two positions.
  • No – The <gml:GeodesicString> is read as a single segment, regardless of the number of positions or interpolations.

A gml_interpolated_segment trait is added to each geometry segment to indicate whether the segment contains interpolated points.

The parameter is useful for identifying and differentiating the geodesic control points from the interpolated points. Any geometry segment with more than two points and gml_interpolated_segment trait set to No is entirely composed of the original control points from the <gml:GeodesicString> element.

Airspace Parameters

Instructs the reader to resolve the contributor airspaces to their vertical and/or horizontal limits.

Valid values: Yes (default), No

Note  For further information, see Airspace Limit Dependencies.

Schema Attributes

Use this parameter to expose Format Attributes in FME Workbench when you create a workspace:

  • In a dynamic scenario, it means these attributes can be passed to the output dataset at runtime.
  • In a non-dynamic scenario, this parameter allows you to expose additional attributes on multiple feature types. Click the browse button to view the available format attributes (which are different for each format) for the reader.