agi.foundation.propagators

(agi.foundation.models-2024r2.jar)

Class Waypoint

java.lang.Object

agi.foundation.propagators.Waypoint

All Implemented Interfaces:

IEquatable<Waypoint>

public class Waypoint
extends Object
implements IEquatable<Waypoint>

Defines the characteristics at a waypoint.

The following example shows how to use the WaypointPropagator to move between waypoints at a constant velocity:

EarthCentralBody earth = CentralBodiesFacet.getFromContext().getEarth();
final double constantVelocity = 80.0;

JulianDate startDate = new JulianDate(new GregorianDate(2007, 12, 6, 12, 0, 0.0));

// Create the start point of our route with a particular date, location, and velocity.
Cartographic point1 = new Cartographic(Trig.degreesToRadians(-77.28), Trig.degreesToRadians(39.94), 3000.0);
Waypoint waypoint1 = new Waypoint(startDate, point1, constantVelocity, 0.0);

// Create the next two waypoints from a location, the same velocity, and the previous waypoint.
Cartographic point2 = new Cartographic(Trig.degreesToRadians(-79.59), Trig.degreesToRadians(38.81), 3000.0);
Waypoint waypoint2 = new Waypoint(waypoint1, earth.getShape(), point2, constantVelocity);

Cartographic point3 = new Cartographic(Trig.degreesToRadians(-81.44), Trig.degreesToRadians(39.69), 3000.0);
Waypoint waypoint3 = new Waypoint(waypoint2, earth.getShape(), point3, constantVelocity);

// Construct the waypoint propagator with all of the waypoints
ArrayList<Waypoint> waypoints = new ArrayList<>();
waypoints.add(waypoint1);
waypoints.add(waypoint2);
waypoints.add(waypoint3);
WaypointPropagator propagator = new WaypointPropagator(earth, waypoints);

// The propagator can then be used to create a Point that represents the position and velocity of the
// vehicle moving between the waypoints.
Point propagatedPoint = propagator.createPoint();

// Or an entire set of ephemeris can be computed at a specified time step.
DateMotionCollection1<Cartesian> ephemeris = propagator.propagate(waypoint1.getDate(), waypoint3.getDate(), Duration.fromSeconds(60.0), 1,
        propagator.getReferenceFrame());

Constructor Summary

Constructors

Constructor and Description
Waypoint(JulianDate date, Cartographic location, double groundSpeed, double rateOfClimb) Initializes a new instance.
Waypoint(Waypoint previousWaypoint, Ellipsoid shape, Cartographic location, double groundSpeed) Initializes a new instance.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj) Indicates whether another object is exactly equal to this instance.
static boolean	equals(Waypoint left, Waypoint right) Returns true if the two instances are exactly equal.
boolean	equalsType(Waypoint other) Indicates whether another instance of this type is equal to this instance.
JulianDate	getDate() Gets the date at which the waypoint is achieved.
double	getGroundSpeed() Gets the speed tangent to the ellipsoid surface.
Cartographic	getLocation() Gets the planetodetic position at the waypoint.
double	getRateOfClimb() Gets the velocity normal to the ellipsoid surface.
int	hashCode() Returns a hash code for this instance, which is suitable for use in hashing algorithms and data structures like a hash table.
static boolean	notEquals(Waypoint left, Waypoint right) Returns true if the two instances are not exactly equal.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Waypoint

public Waypoint(@Nonnull
                JulianDate date,
                @Nonnull
                Cartographic location,
                double groundSpeed,
                double rateOfClimb)

Initializes a new instance.

Parameters:

date - The date at which the waypoint is achieved.

location - The planetodetic position at the waypoint.

groundSpeed - The speed tangent to the ellipsoid surface.

rateOfClimb - The velocity normal to the ellipsoid surface.

Waypoint

public Waypoint(Waypoint previousWaypoint,
                Ellipsoid shape,
                @Nonnull
                Cartographic location,
                double groundSpeed)

Initializes a new instance.

If the previous waypoint is at a different altitude than this one, a RateOfClimb (get) will be selected to achieve a constant vertical acceleration.

Parameters:

previousWaypoint - The previous waypoint in the route.

shape - The shape model on which the waypoints are specified. This will typically be CentralBodiesFacet.GetFromContext().Earth.Shape.

location - The planetodetic location of the new waypoint.

groundSpeed - The speed at which to arrive at this waypoint.

Method Detail

getDate

@Nonnull
public final JulianDate getDate()

Gets the date at which the waypoint is achieved.

getLocation

@Nonnull
public final Cartographic getLocation()

Gets the planetodetic position at the waypoint.

getGroundSpeed

public final double getGroundSpeed()

Gets the speed tangent to the ellipsoid surface.

getRateOfClimb

public final double getRateOfClimb()

Gets the velocity normal to the ellipsoid surface.

equalsType

public final boolean equalsType(Waypoint other)

Indicates whether another instance of this type is equal to this instance. Strict equality is not enforced for waypoints at geographic poles since the longitude coordinate is undefined at these locations.

Specified by:

equalsType in interface IEquatable<Waypoint>

Parameters:

other - The instance to compare to this instance.

Returns:

true if other represents the same value as this instance; otherwise false.

equals

public boolean equals(Object obj)

Indicates whether another object is exactly equal to this instance.

Overrides:

equals in class Object

Parameters:

obj - The object to compare to this instance.

Returns:

true if obj is an instance of this type and represents the same value as this instance; otherwise false.

See Also:

Object.hashCode(), HashMap

hashCode

public int hashCode()

Returns a hash code for this instance, which is suitable for use in hashing algorithms and data structures like a hash table.

Overrides:

hashCode in class Object

Returns:

A hash code for the current object.

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

equals

public static boolean equals(Waypoint left,
                             Waypoint right)

Returns true if the two instances are exactly equal.

Parameters:

left - The instance to compare to right.

right - The instance to compare to left.

Returns:

true if left represents the same value as right; otherwise false.

notEquals

public static boolean notEquals(Waypoint left,
                                Waypoint right)

Returns true if the two instances are not exactly equal.

Parameters:

left - The instance to compare to right.

right - The instance to compare to left.

Returns:

true if left does not represent the same value as right; otherwise false.