Generate Changeover Points (Aviation)

Available with Aviation Charting license.

Summary

Creates changeover points along a route collection comprised of an ordered set of ATSRoute segments.

This tool creates new, or updates the, geometry and attributes of existing changeover point features, deriving the point's location from a changeover distance provided on the input features. The tool also calculates secondary attributes in the Target Changeover Point Features parameter value, DISTANCE1_VAL, which is the distance from the start of a navigational aid (NAVAID) bounded route collection to the changeover point, DISTANCE2_VAL, which is the distance from a changeover point to the end of a NAVAID bounded route collection, and CARTOANGLE_VAL, which is the angle the changeover symbol should be drawn. The CARTOANGLE_VAL, DISTANCE1_VAL, and DISTANCE2_VAL attributes on the Target Changeover Point Features parameter value support symbology and labeling on a chart.

Usage

• The following table lists the data requirements for this tool:

  Item	Requirements
  Location of Changeover distance	Depending on the source of the data, the changeover distance can be provided in either the Input ATS Route Features or Target Changeover Point Features parameter value. If the changeover distance is provided in the Input ATS Route Features parameter value, it must exist in the COPDIST_VAL attribute. If the changeover distance is provided in the Target Changeover Point Features parameter value, it must exist in the Distance1_Val attribute. A changeover’s location is derived by finding the point along a route collection at a given changeover’s distance. The source of the distance must be specified in the Distance Source Type parameter value.
  Route collection indicator	A route collection is defined as a set of connected ATSRoute segments that meet the following criteria: Have a common IDENT_TXT attribute. Order is determined by connecting the STARTPOINT_ID and ENDPOINT_ID attributes. Starts at a NAVAID and ends at a NAVAID. Depending on the source and preparation of the data, the Input ATS Route Features parameter value must specify route collections in one of the following ways: The Input ATS Route Features parameter value can define route collections by having the ENROUTEINFORMATION_ID attribute populated. ATS Route segments with a common ENROUTEINFORMATION_ID field value define a route collection that goes from a NAVAID to a NAVAID. The Group Route Segments tool can be used to prepare ATSRoute with EnrouteInformation_ID attribute groupings that identify segments between NAVAIDs. The Input ATS Route Feature parameter value can define route collections by having the DESCRIPTIONSTART_CODE and DESCRIPTIONEND_CODE attributes populated. These attributes specify when a segment’s start or end is at a NAVAID. The DESCRIPTIONSTART_CODE or DESCRIPTIONEND_CODE value of V (VOR, VOR-DME, VORTAC, TACAN) or N (NDB, NDB/DME) indicates the segment is bound by a NAVAID.
  ATS Route Length	The ATSRoute segments must have their LENGTH_VAL attribute populated with the length of the segment. You can run the Calculate ATS Route Attributes tool to populate the LENGTH_VAL attribute.

• The Input ATS Route Features parameter value must contain the following attributes: ENROUTEINFORMATION_ID (GUID), LENGTH_VAL (Double), IDENT_TXT (Text), STARTPOINT_ID (GUID), ENDPOINT_ID (GUID), COPDIST_VAL (Double), and ROUTETYPE_CODE (Text).

• If the Input ATS Route Features parameter value source data doesn’t define route collections using the ENROUTEINFORMATION_ID attribute, the source data must contain the DESCRIPTIONSTART_CODE and DESCRIPTIONEND_CODE alternate attributes.

• The Target Changeover Point Features parameter value must contain the following attributes: DISTANCE1_VAL (Double), DISTANCE2_VAL (Double), CARTOANGLE_VAL (Double), and ATSROUTE_ID (GUID).

• Specify a Distance Source Type parameter value that is appropriate for the data. This parameter identifies the input that contains the changeover distance value. If the source type option is Point, the tool updates existing changeover point features. If the source type option is Route, the tool inserts new changeover points into the target point layer or updates existing changeover point features.

  • Choose the Route option for the Distance Source Type parameter if changeover distances are stored on route segment features in the ATSRoute layer. In this case, the changeover distance must be stored in an attribute named COPDIST_VAL (Double) in any of the ATS Route segments that are part of a NAVAID bounded route collection. The COPDIST_VAL attribute will be used to derive the location of a changeover point along a NAVAID bounded route collection measured from the start of the route collection. However, if the COPDIST_VAL attribute originates from an ATSRoute segment that has a ROUTETYPE_CODE attribute value of GRNAV, the location of the changeover point will be measured from the start of that segment.

    Note:

    When a changeover point is generated in the Target Changeover Point Features parameter value, the ATSROUTE_ID attribute will be populated differently depending on how the Input ATS Route Features parameter value specified the route collection. If the Input ATS Route Features parameter route collections were specified using the ENROUTEINFORMATION_ID attribute, the changeover point’s ATSROUTE_ID attribute will be populated with the ENROUTEINFORMATION GFID that the ATSRoute segment is a part of. If the Input ATSRoute Features parameter value specified route collections using the DESCRIPTIONSTART_CODE and DESCRIPTIONEND_CODE attributes, the changeover point's ATSROUTE_ID attribute is populated with the ATSROUTE.GFID attribute from which the COPDIST_VAL attribute originated.

  • Choose the Point option for the Distance Source Type parameter if changeover distances are stored in the Target Changeover Point Features parameter value. In this case, the changeover distance must be stored in an attribute named DISTANCE1_VAL (Double), and represents the distance from the start of the route collection to the changeover point. The ATSROUTE_ID (GUID) attribute must be populated with the GFID value of the corresponding ENROUTEINFORMATION_ID attribute of the route collection. The tool updates the geometry and attributes of the changeover point features accordingly.

    Note:

    The Point option is compatible with the tool only when the Target Changeover Point Features parameter value has the ATSROUTE_ID attribute populated with a GUID referring to an ENROUTEINFORMATION row, and the Input ATS Route Features parameter value has the ENROUTEINFORMATION_ID attribute populated with a GUID referring to an ENROUTEINFORMATION GFID that the ATSRoute segment is a part of.

Caution:

This tool modifies the input data. See Tools that modify or update the input data for more information and strategies to avoid undesired data changes.

• The optional Input Route Portions parameter value must contain the following attributes: REFERENCE_ID (GUID), STARTPOINT_ID (GUID), ENDPOINTID (GUID), STARTPOINTCLASS_CODE (Text), ENDPOINTCLASS_CODE (Text), and ENROUTEINFORMATION_ID (GUID).

• The Input Route Portions parameter value specifies the route portions that a changeover point can be associated with. A route portion is part of a larger route collection and each route portion row refers to the STARTPOINT_ID and ENDPOINT_ID attributes. Some data sources specify that a changeover point is to be measured from the start of a route portion instead of from the start of a route collection. A route portion row with a REFERENCE_ID attribute that contains the value of a changeover point GFID will indicate to the tool to measure that changeover point from the route portion.

  Note:

  The Route Portion table can only be used when the Distance Source Type parameter option is set to Point.

• The CARTOANGLE_VAL attribute will be populated with the bearing of the ATSRoute segment that the changeover point is on. Values are -180 to 180 from north and rendered in charts with point symbol Geographic Rotation. When charting, manual cartographic adjustments may be required, depending on the chart projection used.

Parameters

Dialog

Label	Explanation	Data Type
Input ATS Route Features	The input feature class of routes on which changeover points are based. It must contain polyline features.	Feature Layer
Target Changeover Point Features	The point feature class that contains the changeover points. After running the tool, new changeover points are added and existing changeover points are updated.	Feature Layer
Distance Source Type	Specifies the source of the changeover distance value. Route—The changeover distances are stored in the source line layer. Point—The changeover distances are stored in the target point layer.	String
Input Route Portions	The table that specifies the route portions that a changeover point can be associated with.	Table

Derived Output

Label	Explanation	Data Type
Updated Point Features	The output features for changeover points.	Feature Layer

Python

arcpy.aviation.GenerateChangeoverPoints(in_features, target_changeover_features, distance_source_type, in_routeportions)

Name	Explanation	Data Type
in_features	The input feature class of routes on which changeover points are based. It must contain polyline features.	Feature Layer
target_changeover_features	The point feature class that contains the changeover points. After running the tool, new changeover points are added and existing changeover points are updated.	Feature Layer
distance_source_type	Specifies the source of the changeover distance value. ROUTE—The changeover distances are stored in the source line layer. POINT—The changeover distances are stored in the target point layer.	String
in_routeportions	The table that specifies the route portions that a changeover point can be associated with.	Table

Derived Output

Name	Explanation	Data Type
updated_features	The output features for changeover points.	Feature Layer

Code sample

GenerateChangeoverPoints example (stand-alone script)

The following script demonstrates how to use the GenerateChangeoverPoints function.

# Import system modules
import arcpy

# Check out extensions
arcpy.CheckOutExtension('Aeronautical')

# Set local variables
in_features = r"C:\data\AIS.gdb\ATSRoutes"
target_changeover_features = r"C:\data\AIS.gdb\ChangeOver"
distance_source = 'ROUTE'

# Call the GenerateChangeoverPoints tool 
arcpy.aviation.GenerateChangeoverPoints(in_features, target_changeover_features,\
                                        distance_source)

# Check in extensions
arcpy.CheckInExtension('Aeronautical')

Environments

This tool does not use any geoprocessing environments.

Licensing information

• Basic: No
• Standard: Requires ArcGIS Aviation Charting
• Advanced: Requires ArcGIS Aviation Charting