Package org.orekit.utils

Class WaypointPVBuilder

java.lang.Object
org.orekit.utils.WaypointPVBuilder
public class WaypointPVBuilder extends Object
Builder class, enabling incremental building of an PVCoordinatesProvider instance using waypoints defined on an ellipsoid.

Given a series of waypoints ((date, point) tuples), build a PVCoordinatesProvider representing the path. The static methods provide implementations for the most common path definitions (cartesian, great-circle, loxodrome). If these methods are insufficient, the public constructor provides a way to customize the path definition.

This class connects the path segments using the AggregatedPVCoordinatesProvider. As such, no effort is made to smooth the velocity between segments. While position is unaffected, the velocity may be discontinuous between adjacent time points. Thus, care should be taken when modeling paths with abrupt direction changes (e.g. fast-moving aircraft); understand how the PVCoordinatesProvider will be used in the particular application.

Since:
11.3
Author:
Joe Reed

  • Constructor Details

    • WaypointPVBuilder

      public WaypointPVBuilder(WaypointPVBuilder.InterpolationFactory factory, OneAxisEllipsoid body)
      Create a new instance.
      Parameters:
      factory - The factory used to create the intermediate coordinate providers between waypoints.
      body - The central body, on which the way points are defined.

  • Method Details

    • cartesianBuilder

      public static WaypointPVBuilder cartesianBuilder(OneAxisEllipsoid body)
      Construct a waypoint builder interpolating points using a linear cartesian interpolation.
      Parameters:
      body - the reference ellipsoid on which the waypoints are defined.
      Returns:
      the waypoint builder

    • loxodromeBuilder

      public static WaypointPVBuilder loxodromeBuilder(OneAxisEllipsoid body)
      Construct a waypoint builder interpolating points using a loxodrome (or Rhumbline).
      Parameters:
      body - the reference ellipsoid on which the waypoints are defined.
      Returns:
      the waypoint builder

    • greatCircleBuilder

      public static WaypointPVBuilder greatCircleBuilder(OneAxisEllipsoid body)
      Construct a waypoint builder interpolating points using a great-circle.

      The altitude of the intermediate points is linearly interpolated from the bounding waypoints. Extrapolating before the first waypoint or after the last waypoint may result in undefined altitudes.

      Parameters:
      body - the reference ellipsoid on which the waypoints are defined.
      Returns:
      the waypoint builder

    • addWaypoint

      public WaypointPVBuilder addWaypoint(GeodeticPoint point, AbsoluteDate date)
      Add a waypoint.
      Parameters:
      point - the waypoint location
      date - the waypoint time
      Returns:
      this instance

    • invalidBefore

      public WaypointPVBuilder invalidBefore()
      Indicate the resulting PVCoordinatesProvider should be invalid before the first waypoint.
      Returns:
      this instance

    • constantBefore

      public WaypointPVBuilder constantBefore()
      Indicate the resulting PVCoordinatesProvider provide a constant location of the first waypoint prior to the first time.
      Returns:
      this instance

    • invalidAfter

      public WaypointPVBuilder invalidAfter()
      Indicate the resulting PVCoordinatesProvider should be invalid after the last waypoint.
      Returns:
      this instance

    • constantAfter

      public WaypointPVBuilder constantAfter()
      Indicate the resulting PVCoordinatesProvider provide a constant location of the last waypoint after to the last time.
      Returns:
      this instance

    • build

      public PVCoordinatesProvider build()
      Build a PVCoordinatesProvider from the waypoints added to this builder.
      Returns:
      the coordinates provider instance.

    • createInitial

      protected PVCoordinatesProvider createInitial(GeodeticPoint firstPoint)
      Create the initial provider.

      This method uses the internal validBefore flag to either return an invalid PVCoordinatesProvider or a constant one.

      Parameters:
      firstPoint - the first waypoint
      Returns:
      the coordinate provider

    • createFinal

      protected PVCoordinatesProvider createFinal(GeodeticPoint lastPoint)
      Create the final provider.

      This method uses the internal validAfter flag to either return an invalid PVCoordinatesProvider or a constant one.

      Parameters:
      lastPoint - the last waypoint
      Returns:
      the coordinate provider