org.orekit.utils

Class AbsolutePVCoordinates

java.lang.Object

org.orekit.utils.PVCoordinates

org.orekit.utils.TimeStampedPVCoordinates

org.orekit.utils.AbsolutePVCoordinates

All Implemented Interfaces:

Serializable, TimeInterpolable<AbsolutePVCoordinates>, TimeShiftable<PVCoordinates>, TimeStamped, PVCoordinatesProvider

public class AbsolutePVCoordinates
extends TimeStampedPVCoordinates
implements TimeStamped, TimeInterpolable<AbsolutePVCoordinates>, Serializable, PVCoordinatesProvider

Position - Velocity - Acceleration linked to a date and a frame.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.orekit.utils.PVCoordinates

ZERO

Constructor Summary

Constructors

Constructor and Description
AbsolutePVCoordinates(AbsoluteDate date, AbsolutePVCoordinates start, AbsolutePVCoordinates end) Subtractive constructor
AbsolutePVCoordinates(AbsoluteDate date, double a, AbsolutePVCoordinates AbsPva) Multiplicative constructor
AbsolutePVCoordinates(AbsoluteDate date, double a1, AbsolutePVCoordinates absPv1, double a2, AbsolutePVCoordinates absPv2) Linear constructor
AbsolutePVCoordinates(AbsoluteDate date, double a1, AbsolutePVCoordinates absPv1, double a2, AbsolutePVCoordinates absPv2, double a3, AbsolutePVCoordinates absPv3) Linear constructor
AbsolutePVCoordinates(AbsoluteDate date, double a1, AbsolutePVCoordinates absPv1, double a2, AbsolutePVCoordinates absPv2, double a3, AbsolutePVCoordinates absPv3, double a4, AbsolutePVCoordinates absPv4) Linear constructor
AbsolutePVCoordinates(Frame frame, AbsoluteDate date, FieldVector3D<U> p) Builds a AbsolutePVCoordinates triplet from a FieldVector3D<Derivative>.
AbsolutePVCoordinates(Frame frame, AbsoluteDate date, PVCoordinates pva) Build from frame, date and PVA coordinates.
AbsolutePVCoordinates(Frame frame, AbsoluteDate date, Vector3D position, Vector3D velocity) Build from position and velocity.
AbsolutePVCoordinates(Frame frame, AbsoluteDate date, Vector3D position, Vector3D velocity, Vector3D acceleration) Build from position, velocity, acceleration.
AbsolutePVCoordinates(Frame frame, TimeStampedPVCoordinates pva) Build from frame and TimeStampedPVCoordinates.

Method Summary

Modifier and Type	Method and Description
Frame	getFrame() Get the frame in which the coordinates are defined.
TimeStampedPVCoordinates	getPVCoordinates() Get the TimeStampedPVCoordinates.
TimeStampedPVCoordinates	getPVCoordinates(AbsoluteDate otherDate, Frame outputFrame) Get the PVCoordinates of the body in the selected frame.
TimeStampedPVCoordinates	getPVCoordinates(Frame outputFrame) Get the TimeStampedPVCoordinates in a specified frame.
AbsolutePVCoordinates	interpolate(AbsoluteDate date, Stream<AbsolutePVCoordinates> sample) Get an interpolated instance.
static AbsolutePVCoordinates	interpolate(Frame frame, AbsoluteDate date, CartesianDerivativesFilter filter, Stream<AbsolutePVCoordinates> sample) Interpolate position-velocity.
AbsolutePVCoordinates	shiftedBy(double dt) Get a time-shifted state.
PVCoordinatesProvider	toTaylorProvider() Create a local provider using simply Taylor expansion through shiftedBy(double).

Methods inherited from class org.orekit.utils.TimeStampedPVCoordinates

getDate, interpolate, interpolate, toString, toString, toTaylorProvider

Methods inherited from class org.orekit.utils.PVCoordinates

crossProduct, estimateVelocity, getAcceleration, getAngularVelocity, getMomentum, getPosition, getVelocity, negate, normalize, toDerivativeStructurePV, toDerivativeStructureVector, toUnivariateDerivative1PV, toUnivariateDerivative1Vector, toUnivariateDerivative2PV, toUnivariateDerivative2Vector

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.orekit.time.TimeStamped

getDate

Methods inherited from interface org.orekit.time.TimeInterpolable

interpolate

Constructor Detail

AbsolutePVCoordinates

public AbsolutePVCoordinates(Frame frame,
                             AbsoluteDate date,
                             Vector3D position,
                             Vector3D velocity,
                             Vector3D acceleration)

Build from position, velocity, acceleration.

Parameters:

frame - the frame in which the coordinates are defined

date - coordinates date

position - the position vector (m)

velocity - the velocity vector (m/s)

acceleration - the acceleration vector (m/sÂý)

AbsolutePVCoordinates

public AbsolutePVCoordinates(Frame frame,
                             AbsoluteDate date,
                             Vector3D position,
                             Vector3D velocity)

Build from position and velocity. Acceleration is set to zero.

Parameters:

frame - the frame in which the coordinates are defined

date - coordinates date

position - the position vector (m)

velocity - the velocity vector (m/s)

AbsolutePVCoordinates

public AbsolutePVCoordinates(Frame frame,
                             AbsoluteDate date,
                             PVCoordinates pva)

Build from frame, date and PVA coordinates.

Parameters:

frame - the frame in which the coordinates are defined

date - date of the coordinates

pva - TimeStampedPVCoordinates

AbsolutePVCoordinates

public AbsolutePVCoordinates(Frame frame,
                             TimeStampedPVCoordinates pva)

Build from frame and TimeStampedPVCoordinates.

Parameters:

frame - the frame in which the coordinates are defined

pva - TimeStampedPVCoordinates

AbsolutePVCoordinates

public AbsolutePVCoordinates(AbsoluteDate date,
                             double a,
                             AbsolutePVCoordinates AbsPva)

Multiplicative constructor

Build a AbsolutePVCoordinates from another one and a scale factor.

The TimeStampedPVCoordinates built will be a * AbsPva

Parameters:

date - date of the built coordinates

a - scale factor

AbsPva - base (unscaled) AbsolutePVCoordinates

AbsolutePVCoordinates

public AbsolutePVCoordinates(AbsoluteDate date,
                             AbsolutePVCoordinates start,
                             AbsolutePVCoordinates end)

Subtractive constructor

Build a relative AbsolutePVCoordinates from a start and an end position.

The AbsolutePVCoordinates built will be end - start.

In case start and end use two different pseudo-inertial frames, the new AbsolutePVCoordinates arbitrarily be defined in the start frame.

Parameters:

date - date of the built coordinates

start - Starting AbsolutePVCoordinates

end - ending AbsolutePVCoordinates

AbsolutePVCoordinates

public AbsolutePVCoordinates(AbsoluteDate date,
                             double a1,
                             AbsolutePVCoordinates absPv1,
                             double a2,
                             AbsolutePVCoordinates absPv2)

Linear constructor

Build a AbsolutePVCoordinates from two other ones and corresponding scale factors.

The AbsolutePVCoordinates built will be a1 * u1 + a2 * u2

In case the AbsolutePVCoordinates use different pseudo-inertial frames, the new AbsolutePVCoordinates arbitrarily be defined in the first frame.

Parameters:

date - date of the built coordinates

a1 - first scale factor

absPv1 - first base (unscaled) AbsolutePVCoordinates

a2 - second scale factor

absPv2 - second base (unscaled) AbsolutePVCoordinates

AbsolutePVCoordinates

public AbsolutePVCoordinates(AbsoluteDate date,
                             double a1,
                             AbsolutePVCoordinates absPv1,
                             double a2,
                             AbsolutePVCoordinates absPv2,
                             double a3,
                             AbsolutePVCoordinates absPv3)

Linear constructor

Build a AbsolutePVCoordinates from three other ones and corresponding scale factors.

The AbsolutePVCoordinates built will be a1 * u1 + a2 * u2 + a3 * u3

In case the AbsolutePVCoordinates use different pseudo-inertial frames, the new AbsolutePVCoordinates arbitrarily be defined in the first frame.

Parameters:

date - date of the built coordinates

a1 - first scale factor

absPv1 - first base (unscaled) AbsolutePVCoordinates

a2 - second scale factor

absPv2 - second base (unscaled) AbsolutePVCoordinates

a3 - third scale factor

absPv3 - third base (unscaled) AbsolutePVCoordinates

AbsolutePVCoordinates

public AbsolutePVCoordinates(AbsoluteDate date,
                             double a1,
                             AbsolutePVCoordinates absPv1,
                             double a2,
                             AbsolutePVCoordinates absPv2,
                             double a3,
                             AbsolutePVCoordinates absPv3,
                             double a4,
                             AbsolutePVCoordinates absPv4)

Linear constructor

Build a AbsolutePVCoordinates from four other ones and corresponding scale factors.

The AbsolutePVCoordinates built will be a1 * u1 + a2 * u2 + a3 * u3 + a4 * u4

In case the AbsolutePVCoordinates use different pseudo-inertial frames, the new AbsolutePVCoordinates arbitrarily be defined in the first frame.

Parameters:

date - date of the built coordinates

a1 - first scale factor

absPv1 - first base (unscaled) AbsolutePVCoordinates

a2 - second scale factor

absPv2 - second base (unscaled) AbsolutePVCoordinates

a3 - third scale factor

absPv3 - third base (unscaled) AbsolutePVCoordinates

a4 - fourth scale factor

absPv4 - fourth base (unscaled) AbsolutePVCoordinates

AbsolutePVCoordinates

public AbsolutePVCoordinates(Frame frame,
                             AbsoluteDate date,
                             FieldVector3D<U> p)

Builds a AbsolutePVCoordinates triplet from a FieldVector3D<Derivative>.

The vector components must have time as their only derivation parameter and have consistent derivation orders.

Type Parameters:

U - type of the derivative

Parameters:

frame - the frame in which the parameters are defined

date - date of the built coordinates

p - vector with time-derivatives embedded within the coordinates

Method Detail

shiftedBy

public AbsolutePVCoordinates shiftedBy(double dt)

Get a time-shifted state.

The state can be slightly shifted to close dates. This shift is based on a simple Taylor expansion. It is not intended as a replacement for proper orbit propagation (it is not even Keplerian!) but should be sufficient for either small time shifts or coarse accuracy.

Specified by:

shiftedBy in interface TimeShiftable<PVCoordinates>

Overrides:

shiftedBy in class TimeStampedPVCoordinates

Parameters:

dt - time shift in seconds

Returns:

a new state, shifted with respect to the instance (which is immutable)

toTaylorProvider

public PVCoordinatesProvider toTaylorProvider()

Create a local provider using simply Taylor expansion through shiftedBy(double).

The time evolution is based on a simple Taylor expansion. It is not intended as a replacement for proper orbit propagation (it is not even Keplerian!) but should be sufficient for either small time shifts or coarse accuracy.

Returns:

provider based on Taylor expansion, for small time shifts around instance date

getFrame

public Frame getFrame()

Get the frame in which the coordinates are defined.

Returns:

frame in which the coordinates are defined

getPVCoordinates

public TimeStampedPVCoordinates getPVCoordinates()

Get the TimeStampedPVCoordinates.

Returns:

TimeStampedPVCoordinates

getPVCoordinates

public TimeStampedPVCoordinates getPVCoordinates(Frame outputFrame)

Get the TimeStampedPVCoordinates in a specified frame.

Parameters:

outputFrame - frame in which the position/velocity coordinates shall be computed

Returns:

TimeStampedPVCoordinates

Throws:

OrekitException - if transformation between frames cannot be computed

See Also:

getPVCoordinates()

getPVCoordinates

public TimeStampedPVCoordinates getPVCoordinates(AbsoluteDate otherDate,
                                                 Frame outputFrame)

Description copied from interface: PVCoordinatesProvider

Get the PVCoordinates of the body in the selected frame.

Specified by:

getPVCoordinates in interface PVCoordinatesProvider

Parameters:

otherDate - current date

outputFrame - the frame where to define the position

Returns:

time-stamped position/velocity of the body (m and m/s)

interpolate

public AbsolutePVCoordinates interpolate(AbsoluteDate date,
                                         Stream<AbsolutePVCoordinates> sample)

Description copied from interface: TimeInterpolable

Get an interpolated instance.

Note that the state of the current instance may not be used in the interpolation process, only its type and non interpolable fields are used (for example central attraction coefficient or frame when interpolating orbits). The interpolable fields taken into account are taken only from the states of the sample points. So if the state of the instance must be used, the instance should be included in the sample points.

Note that this method is designed for small samples only (say up to about 10-20 points) so it can be implemented using polynomial interpolation (typically Hermite interpolation). Using too much points may induce Runge's phenomenon and numerical problems (including NaN appearing).

Specified by:

interpolate in interface TimeInterpolable<AbsolutePVCoordinates>

Parameters:

date - interpolation date

sample - sample points on which interpolation should be done

Returns:

a new instance, interpolated at specified date

interpolate

public static AbsolutePVCoordinates interpolate(Frame frame,
                                                AbsoluteDate date,
                                                CartesianDerivativesFilter filter,
                                                Stream<AbsolutePVCoordinates> sample)

Interpolate position-velocity.

The interpolated instance is created by polynomial Hermite interpolation ensuring velocity remains the exact derivative of position.

Note that even if first time derivatives (velocities) from sample can be ignored, the interpolated instance always includes interpolated derivatives. This feature can be used explicitly to compute these derivatives when it would be too complex to compute them from an analytical formula: just compute a few sample points from the explicit formula and set the derivatives to zero in these sample points, then use interpolation to add derivatives consistent with the positions.

Parameters:

frame - frame for the interpolted instance

date - interpolation date

filter - filter for derivatives from the sample to use in interpolation

sample - sample points on which interpolation should be done

Returns:

a new position-velocity, interpolated at specified date

Throws:

OrekitIllegalArgumentException - if some elements in the sample do not have the same defining frame as other