fr.cnes.sirius.patrius.orbits.pvcoordinates

Class TimeStampedPVCoordinates

java.lang.Object

fr.cnes.sirius.patrius.orbits.pvcoordinates.PVCoordinates

fr.cnes.sirius.patrius.orbits.pvcoordinates.TimeStampedPVCoordinates

All Implemented Interfaces:

TimeShiftable<PVCoordinates>, TimeStamped, Serializable

public class TimeStampedPVCoordinates
extends PVCoordinates
implements TimeStamped

time-stamped version of PVCoordinates.

Instances of this class are guaranteed to be immutable.

Since:

3.1

Author:

Luc Maisonobe

See Also:

Serialized Form

Field Summary

Fields inherited from class fr.cnes.sirius.patrius.orbits.pvcoordinates.PVCoordinates

ZERO

Constructor Summary

Constructors

Constructor and Description
TimeStampedPVCoordinates(AbsoluteDate dateIn, double a, PVCoordinates pv) Multiplicative constructor
TimeStampedPVCoordinates(AbsoluteDate dateIn, double a1, PVCoordinates pv1, double a2, PVCoordinates pv2) Linear constructor
TimeStampedPVCoordinates(AbsoluteDate dateIn, double a1, PVCoordinates pv1, double a2, PVCoordinates pv2, double a3, PVCoordinates pv3) Linear constructor
TimeStampedPVCoordinates(AbsoluteDate dateIn, double a1, PVCoordinates pv1, double a2, PVCoordinates pv2, double a3, PVCoordinates pv3, double a4, PVCoordinates pv4) Linear constructor
TimeStampedPVCoordinates(AbsoluteDate dateIn, FieldVector3D<DerivativeStructure> p) Builds a TimeStampedPVCoordinates triplet from a FieldVector3D<DerivativeStructure>.
TimeStampedPVCoordinates(AbsoluteDate dateIn, PVCoordinates pv) Build from position velocity acceleration coordinates.
TimeStampedPVCoordinates(AbsoluteDate dateIn, PVCoordinates start, PVCoordinates end) Subtractive constructor
TimeStampedPVCoordinates(AbsoluteDate dateIn, Vector3D position, Vector3D velocity) Build from position and velocity.
TimeStampedPVCoordinates(AbsoluteDate dateIn, Vector3D position, Vector3D velocity, Vector3D acceleration) Builds a TimeStampedPVCoordinates triplet.

Method Summary

Modifier and Type	Method and Description
static Function<AbsoluteDate,TimeStampedPVCoordinates>	buildInterpolationFunction(TimeStampedPVCoordinates[] samples, int indexInf, int indexSup, CartesianDerivativesFilter filter, boolean computeAcceleration) Build an interpolation function for the TimeStampedPVCoordinates.
boolean	equals(Object object)
AbsoluteDate	getDate() Get the date.
int	hashCode()
static TimeStampedPVCoordinates	interpolate(AbsoluteDate date, CartesianDerivativesFilter filter, Collection<TimeStampedPVCoordinates> sample) Interpolate position-velocity.
TimeStampedPVCoordinates	shiftedBy(double dt) Get a time-shifted state.
String	toString() Return a string representation of this position/velocity pair.

Methods inherited from class fr.cnes.sirius.patrius.orbits.pvcoordinates.PVCoordinates

crossProduct, estimateVelocity, getAcceleration, getAngularVelocity, getMomentum, getPosition, getVelocity, negate, normalize, toArray, toDerivativeStructureVector

Methods inherited from class java.lang.Object

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

Constructor Detail

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                Vector3D position,
                                Vector3D velocity,
                                Vector3D acceleration)

Builds a TimeStampedPVCoordinates triplet.

Parameters:

dateIn - coordinates date

position - the position vector (m)

velocity - the velocity vector (m/s)

acceleration - the acceleration vector (m/s²)

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                Vector3D position,
                                Vector3D velocity)

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

Parameters:

dateIn - coordinates date

position - the position vector (m)

velocity - the velocity vector (m/s)

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                PVCoordinates pv)

Build from position velocity acceleration coordinates.

Parameters:

dateIn - coordinates date

pv - position velocity, and acceleration coordinates, in meters and seconds.

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                double a,
                                PVCoordinates pv)

Multiplicative constructor

Build a TimeStampedPVCoordinates from another one and a scale factor.

The TimeStampedPVCoordinates built will be a * pv

Parameters:

dateIn - date of the built coordinates

a - scale factor

pv - base (unscaled) PVCoordinates

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                PVCoordinates start,
                                PVCoordinates end)

Subtractive constructor

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

The TimeStampedPVCoordinates built will be end - start.

Parameters:

dateIn - date of the built coordinates

start - Starting PVCoordinates

end - ending PVCoordinates

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                double a1,
                                PVCoordinates pv1,
                                double a2,
                                PVCoordinates pv2)

Linear constructor

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

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

Parameters:

dateIn - date of the built coordinates

a1 - first scale factor

pv1 - first base (unscaled) PVCoordinates

a2 - second scale factor

pv2 - second base (unscaled) PVCoordinates

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                double a1,
                                PVCoordinates pv1,
                                double a2,
                                PVCoordinates pv2,
                                double a3,
                                PVCoordinates pv3)

Linear constructor

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

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

Parameters:

dateIn - date of the built coordinates

a1 - first scale factor

pv1 - first base (unscaled) PVCoordinates

a2 - second scale factor

pv2 - second base (unscaled) PVCoordinates

a3 - third scale factor

pv3 - third base (unscaled) PVCoordinates

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                double a1,
                                PVCoordinates pv1,
                                double a2,
                                PVCoordinates pv2,
                                double a3,
                                PVCoordinates pv3,
                                double a4,
                                PVCoordinates pv4)

Linear constructor

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

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

Parameters:

dateIn - date of the built coordinates

a1 - first scale factor

pv1 - first base (unscaled) PVCoordinates

a2 - second scale factor

pv2 - second base (unscaled) PVCoordinates

a3 - third scale factor

pv3 - third base (unscaled) PVCoordinates

a4 - fourth scale factor

pv4 - fourth base (unscaled) PVCoordinates

TimeStampedPVCoordinates

public TimeStampedPVCoordinates(AbsoluteDate dateIn,
                                FieldVector3D<DerivativeStructure> p)

Builds a TimeStampedPVCoordinates triplet from a FieldVector3D<DerivativeStructure>.

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

Parameters:

dateIn - date of the built coordinates

p - vector with time-derivatives embedded within the coordinates

Method Detail

getDate

public AbsoluteDate getDate()

Get the date.

Specified by:

getDate in interface TimeStamped

Returns:

date attached to the object

shiftedBy

public TimeStampedPVCoordinates 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 PVCoordinates

Parameters:

dt - time shift in seconds

Returns:

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

See Also:

AbsoluteDate.shiftedBy(double), Attitude.shiftedBy(double), Orbit.shiftedBy(double), SpacecraftState.shiftedBy(double)

toString

public String toString()

Return a string representation of this position/velocity pair.

Overrides:

toString in class PVCoordinates

Returns:

string representation of this position/velocity pair

equals

public boolean equals(Object object)

Overrides:

equals in class PVCoordinates

hashCode

public int hashCode()

Overrides:

hashCode in class PVCoordinates

interpolate

public static TimeStampedPVCoordinates interpolate(AbsoluteDate date,
                                                   CartesianDerivativesFilter filter,
                                                   Collection<TimeStampedPVCoordinates> 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:

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

buildInterpolationFunction

public static Function<AbsoluteDate,TimeStampedPVCoordinates> buildInterpolationFunction(TimeStampedPVCoordinates[] samples,
                                                                                         int indexInf,
                                                                                         int indexSup,
                                                                                         CartesianDerivativesFilter filter,
                                                                                         boolean computeAcceleration)

Build an interpolation function for the TimeStampedPVCoordinates.

Note: this interpolation function can produce small numerical differences compared to the interpolate(AbsoluteDate, CartesianDerivativesFilter, Collection) method, as both methods don't build the dataset abscissas the same way: this one with the first date of the samples as origin, the other with the interpolated date as origin.

Parameters:

samples - The samples of time stamped PV data. It should be sorted.

indexInf - Inferior index

indexSup - Superior index

filter - Filter describing which derivatives to use in TimeStampedPVCoordinates and interpolation

computeAcceleration - true if the acceleration should be computed, false otherwise

Returns:

interpolation function for the TimeStampedPVCoordinates