Package org.orekit.orbits

Class FieldKeplerianOrbit<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.orbits.FieldOrbit<T>

org.orekit.orbits.FieldKeplerianOrbit<T>

Type Parameters:

T - type of the field elements

All Implemented Interfaces:

PositionAngleBased, FieldTimeShiftable<FieldOrbit<T>,T>, FieldTimeStamped<T>, TimeShiftable<FieldOrbit<T>>, FieldPVCoordinatesProvider<T>

public class FieldKeplerianOrbit<T extends CalculusFieldElement<T>>
extends FieldOrbit<T>
implements PositionAngleBased

This class handles traditional Keplerian orbital parameters.

The parameters used internally are the classical Keplerian elements:

     a
     e
     i
     ω
     Ω
     v
   

where ω stands for the Perigee Argument, Ω stands for the Right Ascension of the Ascending Node and v stands for the true anomaly.

This class supports hyperbolic orbits, using the convention that semi major axis is negative for such orbits (and of course eccentricity is greater than 1).

When orbit is either equatorial or circular, some Keplerian elements (more precisely ω and Ω) become ambiguous so this class should not be used for such orbits. For this reason, equinoctial orbits is the recommended way to represent orbits.

The instance KeplerianOrbit is guaranteed to be immutable.

Since:

9.0

Author:

Luc Maisonobe, Guylaine Prat, Fabien Maussion, Véronique Pommier-Maurussane, Andrea Antolino

See Also:

Orbit, CircularOrbit, CartesianOrbit, EquinoctialOrbit

Field Summary

Fields inherited from class org.orekit.orbits.FieldOrbit

TOLERANCE_POSITION_ANGLE_RATE

Constructor Summary

Constructors

Constructor	Description
FieldKeplerianOrbit(Field<T> field, KeplerianOrbit op)	Constructor from Field and KeplerianOrbit.
FieldKeplerianOrbit(Field<T> field, Orbit op)	Constructor from Field and Orbit.
FieldKeplerianOrbit(FieldOrbit<T> op)	Constructor from any kind of orbital parameters.
FieldKeplerianOrbit(FieldPVCoordinates<T> FieldPVCoordinates, Frame frame, FieldAbsoluteDate<T> date, T mu)	Constructor from Cartesian parameters.
FieldKeplerianOrbit(TimeStampedFieldPVCoordinates<T> pvCoordinates, Frame frame, T mu)	Constructor from Cartesian parameters.
FieldKeplerianOrbit(T a, T e, T i, T pa, T raan, T anomaly, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldKeplerianOrbit(T a, T e, T i, T pa, T raan, T anomaly, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldKeplerianOrbit(T a, T e, T i, T pa, T raan, T anomaly, T aDot, T eDot, T iDot, T paDot, T raanDot, T anomalyDot, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldKeplerianOrbit(T a, T e, T i, T pa, T raan, T anomaly, T aDot, T eDot, T iDot, T paDot, T raanDot, T anomalyDot, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
void	addKeplerContribution(PositionAngleType type, T gm, T[] pDot)	Add the contribution of the Keplerian motion to parameters derivatives
protected T[][]	computeJacobianEccentricWrtCartesian()	Compute the Jacobian of the orbital parameters with eccentric angle with respect to the Cartesian parameters.
protected T[][]	computeJacobianMeanWrtCartesian()	Compute the Jacobian of the orbital parameters with mean angle with respect to the Cartesian parameters.
protected T[][]	computeJacobianTrueWrtCartesian()	Compute the Jacobian of the orbital parameters with true angle with respect to the Cartesian parameters.
T	getA()	Get the semi-major axis.
T	getADot()	Get the semi-major axis derivative.
T	getAnomaly(PositionAngleType type)	Get the anomaly.
T	getAnomalyDot(PositionAngleType type)	Get the anomaly derivative.
PositionAngleType	getCachedPositionAngleType()	Get the cached PositionAngleType.
T	getE()	Get the eccentricity.
T	getEccentricAnomaly()	Get the eccentric anomaly.
T	getEccentricAnomalyDot()	Get the eccentric anomaly derivative.
T	getEDot()	Get the eccentricity derivative.
T	getEquinoctialEx()	Get the first component of the equinoctial eccentricity vector.
T	getEquinoctialExDot()	Get the first component of the equinoctial eccentricity vector derivative.
T	getEquinoctialEy()	Get the second component of the equinoctial eccentricity vector.
T	getEquinoctialEyDot()	Get the second component of the equinoctial eccentricity vector derivative.
T	getHx()	Get the first component of the inclination vector.
T	getHxDot()	Get the first component of the inclination vector derivative.
T	getHy()	Get the second component of the inclination vector.
T	getHyDot()	Get the second component of the inclination vector derivative.
T	getI()	Get the inclination.
T	getIDot()	Get the inclination derivative.
T	getLE()	Get the eccentric longitude argument.
T	getLEDot()	Get the eccentric longitude argument derivative.
T	getLM()	Get the mean longitude argument.
T	getLMDot()	Get the mean longitude argument derivative.
T	getLv()	Get the true longitude argument.
T	getLvDot()	Get the true longitude argument derivative.
T	getMeanAnomaly()	Get the mean anomaly.
T	getMeanAnomalyDot()	Get the mean anomaly derivative.
T	getPerigeeArgument()	Get the perigee argument.
T	getPerigeeArgumentDot()	Get the perigee argument derivative.
T	getRightAscensionOfAscendingNode()	Get the right ascension of the ascending node.
T	getRightAscensionOfAscendingNodeDot()	Get the right ascension of the ascending node derivative.
T	getTrueAnomaly()	Get the true anomaly.
T	getTrueAnomalyDot()	Get the true anomaly derivative.
OrbitType	getType()	Get the orbit type.
boolean	hasNonKeplerianAcceleration()	Check if orbit includes non-Keplerian rates.
boolean	hasNonKeplerianRates()	Tells whether the instance holds rates (first-order time derivatives) for dependent variables that are incompatible with Keplerian motion.
protected FieldVector3D<T>	initPosition()	Compute the position coordinates from the canonical parameters.
protected TimeStampedFieldPVCoordinates<T>	initPVCoordinates()	Compute the position/velocity coordinates from the canonical parameters.
FieldKeplerianOrbit<T>	shiftedBy(double dt)	Get a time-shifted instance.
FieldKeplerianOrbit<T>	shiftedBy(T dt)	Get a time-shifted orbit.
KeplerianOrbit	toOrbit()	Transforms the FieldOrbit instance into an Orbit instance.
String	toString()	Returns a string representation of this Keplerian parameters object.
FieldKeplerianOrbit<T>	withFrame(Frame inertialFrame)	Create a new object representing the same physical orbital state, but attached to a different reference frame.
FieldKeplerianOrbit<T>	withKeplerianRates()	Create a new instance such that PositionAngleBased.hasNonKeplerianRates() is false.

Methods inherited from class org.orekit.orbits.FieldOrbit

fillHalfRow, fillHalfRow, fillHalfRow, fillHalfRow, fillHalfRow, fillHalfRow, getDate, getField, getFrame, getJacobianWrtCartesian, getJacobianWrtParameters, getKeplerianMeanMotion, getKeplerianPeriod, getMeanAnomalyDotWrtA, getMu, getOne, getPosition, getPosition, getPosition, getPVCoordinates, getPVCoordinates, getPVCoordinates, getZero, hasNonKeplerianAcceleration, isElliptical

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.time.FieldTimeStamped

durationFrom

Methods inherited from interface org.orekit.time.TimeShiftable

shiftedBy

Constructor Detail

FieldKeplerianOrbit

public FieldKeplerianOrbit(T a,
                           T e,
                           T i,
                           T pa,
                           T raan,
                           T anomaly,
                           PositionAngleType type,
                           PositionAngleType cachedPositionAngleType,
                           Frame frame,
                           FieldAbsoluteDate<T> date,
                           T mu)
                    throws IllegalArgumentException

Creates a new instance.

Parameters:

a - semi-major axis (m), negative for hyperbolic orbits

e - eccentricity (positive or equal to 0)

i - inclination (rad)

pa - perigee argument (ω, rad)

raan - right ascension of ascending node (Ω, rad)

anomaly - mean, eccentric or true anomaly (rad)

type - type of anomaly

cachedPositionAngleType - type of cached anomaly

frame - the frame in which the parameters are defined (must be a pseudo-inertial frame)

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits

Since:

12.1

FieldKeplerianOrbit

public FieldKeplerianOrbit(T a,
                           T e,
                           T i,
                           T pa,
                           T raan,
                           T anomaly,
                           PositionAngleType type,
                           Frame frame,
                           FieldAbsoluteDate<T> date,
                           T mu)
                    throws IllegalArgumentException

Creates a new instance.

Parameters:

a - semi-major axis (m), negative for hyperbolic orbits

e - eccentricity (positive or equal to 0)

i - inclination (rad)

pa - perigee argument (ω, rad)

raan - right ascension of ascending node (Ω, rad)

anomaly - mean, eccentric or true anomaly (rad)

type - type of anomaly

frame - the frame in which the parameters are defined (must be a pseudo-inertial frame)

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits

Since:

12.1

FieldKeplerianOrbit

public FieldKeplerianOrbit(T a,
                           T e,
                           T i,
                           T pa,
                           T raan,
                           T anomaly,
                           T aDot,
                           T eDot,
                           T iDot,
                           T paDot,
                           T raanDot,
                           T anomalyDot,
                           PositionAngleType type,
                           PositionAngleType cachedPositionAngleType,
                           Frame frame,
                           FieldAbsoluteDate<T> date,
                           T mu)
                    throws IllegalArgumentException

Creates a new instance.

Parameters:

a - semi-major axis (m), negative for hyperbolic orbits

e - eccentricity (positive or equal to 0)

i - inclination (rad)

pa - perigee argument (ω, rad)

raan - right ascension of ascending node (Ω, rad)

anomaly - mean, eccentric or true anomaly (rad)

aDot - semi-major axis derivative, null if unknown (m/s)

eDot - eccentricity derivative, null if unknown

iDot - inclination derivative, null if unknown (rad/s)

paDot - perigee argument derivative, null if unknown (rad/s)

raanDot - right ascension of ascending node derivative, null if unknown (rad/s)

anomalyDot - mean, eccentric or true anomaly derivative, null if unknown (rad/s)

type - type of anomaly

cachedPositionAngleType - type of cached anomaly

frame - the frame in which the parameters are defined (must be a pseudo-inertial frame)

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits

Since:

12.1

FieldKeplerianOrbit

public FieldKeplerianOrbit(T a,
                           T e,
                           T i,
                           T pa,
                           T raan,
                           T anomaly,
                           T aDot,
                           T eDot,
                           T iDot,
                           T paDot,
                           T raanDot,
                           T anomalyDot,
                           PositionAngleType type,
                           Frame frame,
                           FieldAbsoluteDate<T> date,
                           T mu)
                    throws IllegalArgumentException

Creates a new instance.

Parameters:

a - semi-major axis (m), negative for hyperbolic orbits

e - eccentricity (positive or equal to 0)

i - inclination (rad)

pa - perigee argument (ω, rad)

raan - right ascension of ascending node (Ω, rad)

anomaly - mean, eccentric or true anomaly (rad)

aDot - semi-major axis derivative, null if unknown (m/s)

eDot - eccentricity derivative, null if unknown

iDot - inclination derivative, null if unknown (rad/s)

paDot - perigee argument derivative, null if unknown (rad/s)

raanDot - right ascension of ascending node derivative, null if unknown (rad/s)

anomalyDot - mean, eccentric or true anomaly derivative, null if unknown (rad/s)

type - type of anomaly

frame - the frame in which the parameters are defined (must be a pseudo-inertial frame)

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits

FieldKeplerianOrbit

public FieldKeplerianOrbit(TimeStampedFieldPVCoordinates<T> pvCoordinates,
                           Frame frame,
                           T mu)
                    throws IllegalArgumentException

Constructor from Cartesian parameters.

The acceleration provided in FieldPVCoordinates is accessible using FieldOrbit.getPVCoordinates() and FieldOrbit.getPVCoordinates(Frame). All other methods use mu and the position to compute the acceleration, including shiftedBy(CalculusFieldElement) and FieldOrbit.getPVCoordinates(FieldAbsoluteDate, Frame).

Parameters:

pvCoordinates - the PVCoordinates of the satellite

frame - the frame in which are defined the FieldPVCoordinates (must be a pseudo-inertial frame)

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if frame is not a pseudo-inertial frame

FieldKeplerianOrbit

public FieldKeplerianOrbit(FieldPVCoordinates<T> FieldPVCoordinates,
                           Frame frame,
                           FieldAbsoluteDate<T> date,
                           T mu)
                    throws IllegalArgumentException

Constructor from Cartesian parameters.

The acceleration provided in FieldPVCoordinates is accessible using FieldOrbit.getPVCoordinates() and FieldOrbit.getPVCoordinates(Frame). All other methods use mu and the position to compute the acceleration, including shiftedBy(CalculusFieldElement) and FieldOrbit.getPVCoordinates(FieldAbsoluteDate, Frame).

Parameters:

FieldPVCoordinates - the PVCoordinates of the satellite

frame - the frame in which are defined the FieldPVCoordinates (must be a pseudo-inertial frame)

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if frame is not a pseudo-inertial frame

FieldKeplerianOrbit

public FieldKeplerianOrbit(FieldOrbit<T> op)

Constructor from any kind of orbital parameters.

Parameters:

op - orbital parameters to copy

FieldKeplerianOrbit

public FieldKeplerianOrbit(Field<T> field,
                           KeplerianOrbit op)

Constructor from Field and KeplerianOrbit.

Build a FieldKeplerianOrbit from non-Field KeplerianOrbit.

Parameters:

field - CalculusField to base object on

op - non-field orbit with only "constant" terms

Since:

12.0

FieldKeplerianOrbit

public FieldKeplerianOrbit(Field<T> field,
                           Orbit op)

Constructor from Field and Orbit.

Build a FieldKeplerianOrbit from any non-Field Orbit.

Parameters:

field - CalculusField to base object on

op - non-field orbit with only "constant" terms

Since:

12.0

Method Detail

getType

public OrbitType getType()

Get the orbit type.

Specified by:

getType in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

orbit type

getA

public T getA()

Get the semi-major axis.

Note that the semi-major axis is considered negative for hyperbolic orbits.

Specified by:

getA in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

semi-major axis (m)

getADot

public T getADot()

Get the semi-major axis derivative.

Note that the semi-major axis is considered negative for hyperbolic orbits.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getADot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

semi-major axis derivative (m/s)

getE

public T getE()

Get the eccentricity.

Specified by:

getE in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

eccentricity

getEDot

public T getEDot()

Get the eccentricity derivative.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getEDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

eccentricity derivative

getI

public T getI()

Get the inclination.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getI in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

inclination (rad)

getIDot

public T getIDot()

Get the inclination derivative.

Specified by:

getIDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

inclination derivative (rad/s)

getPerigeeArgument

public T getPerigeeArgument()

Get the perigee argument.

Returns:

perigee argument (rad)

getPerigeeArgumentDot

public T getPerigeeArgumentDot()

Get the perigee argument derivative.

Returns:

perigee argument derivative (rad/s)

getRightAscensionOfAscendingNode

public T getRightAscensionOfAscendingNode()

Get the right ascension of the ascending node.

Returns:

right ascension of the ascending node (rad)

getRightAscensionOfAscendingNodeDot

public T getRightAscensionOfAscendingNodeDot()

Get the right ascension of the ascending node derivative.

Returns:

right ascension of the ascending node derivative (rad/s)

getTrueAnomaly

public T getTrueAnomaly()

Get the true anomaly.

Returns:

true anomaly (rad)

getTrueAnomalyDot

public T getTrueAnomalyDot()

Get the true anomaly derivative.

Returns:

true anomaly derivative (rad/s)

getEccentricAnomaly

public T getEccentricAnomaly()

Get the eccentric anomaly.

Returns:

eccentric anomaly (rad)

getEccentricAnomalyDot

public T getEccentricAnomalyDot()

Get the eccentric anomaly derivative.

Returns:

eccentric anomaly derivative (rad/s)

getMeanAnomaly

public T getMeanAnomaly()

Get the mean anomaly.

Returns:

mean anomaly (rad)

getMeanAnomalyDot

public T getMeanAnomalyDot()

Get the mean anomaly derivative.

Returns:

mean anomaly derivative (rad/s)

getAnomaly

public T getAnomaly(PositionAngleType type)

Get the anomaly.

Parameters:

type - type of the angle

Returns:

anomaly (rad)

getAnomalyDot

public T getAnomalyDot(PositionAngleType type)

Get the anomaly derivative.

Parameters:

type - type of the angle

Returns:

anomaly derivative (rad/s)

hasNonKeplerianAcceleration

public boolean hasNonKeplerianAcceleration()

Check if orbit includes non-Keplerian rates.

Overrides:

hasNonKeplerianAcceleration in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

true if orbit includes non-Keplerian derivatives

See Also:

FieldOrbit.getADot(), FieldOrbit.getEquinoctialExDot(), FieldOrbit.getEquinoctialEyDot(), FieldOrbit.getHxDot(), FieldOrbit.getHyDot(), FieldOrbit.getLEDot(), FieldOrbit.getLvDot(), FieldOrbit.getLMDot(), FieldOrbit.getEDot(), FieldOrbit.getIDot()

getEquinoctialEx

public T getEquinoctialEx()

Get the first component of the equinoctial eccentricity vector.

Specified by:

getEquinoctialEx in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

first component of the equinoctial eccentricity vector

getEquinoctialExDot

public T getEquinoctialExDot()

Get the first component of the equinoctial eccentricity vector derivative.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getEquinoctialExDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

first component of the equinoctial eccentricity vector derivative

getEquinoctialEy

public T getEquinoctialEy()

Get the second component of the equinoctial eccentricity vector.

Specified by:

getEquinoctialEy in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

second component of the equinoctial eccentricity vector

getEquinoctialEyDot

public T getEquinoctialEyDot()

Get the second component of the equinoctial eccentricity vector derivative.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getEquinoctialEyDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

second component of the equinoctial eccentricity vector derivative

getHx

public T getHx()

Get the first component of the inclination vector.

Specified by:

getHx in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

first component of the inclination vector

getHxDot

public T getHxDot()

Get the first component of the inclination vector derivative.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getHxDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

first component of the inclination vector derivative

getHy

public T getHy()

Get the second component of the inclination vector.

Specified by:

getHy in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

second component of the inclination vector

getHyDot

public T getHyDot()

Get the second component of the inclination vector derivative.

Specified by:

getHyDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

second component of the inclination vector derivative

getLv

public T getLv()

Get the true longitude argument.

Specified by:

getLv in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

v + ω + Ω true longitude argument (rad)

getLvDot

public T getLvDot()

Get the true longitude argument derivative.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getLvDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

d(v + ω + Ω)/dt true longitude argument derivative (rad/s)

getLE

public T getLE()

Get the eccentric longitude argument.

Specified by:

getLE in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

E + ω + Ω eccentric longitude argument (rad)

getLEDot

public T getLEDot()

Get the eccentric longitude argument derivative.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getLEDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

d(E + ω + Ω)/dt eccentric longitude argument derivative (rad/s)

getLM

public T getLM()

Get the mean longitude argument.

Specified by:

getLM in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

M + ω + Ω mean longitude argument (rad)

getLMDot

public T getLMDot()

Get the mean longitude argument derivative.

If the orbit was created without derivatives, the value returned is null.

Specified by:

getLMDot in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

d(M + ω + Ω)/dt mean longitude argument derivative (rad/s)

initPosition

protected FieldVector3D<T> initPosition()

Compute the position coordinates from the canonical parameters.

Specified by:

initPosition in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

computed position coordinates

initPVCoordinates

protected TimeStampedFieldPVCoordinates<T> initPVCoordinates()

Compute the position/velocity coordinates from the canonical parameters.

Specified by:

initPVCoordinates in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

computed position/velocity coordinates

withFrame

public FieldKeplerianOrbit<T> withFrame(Frame inertialFrame)

Create a new object representing the same physical orbital state, but attached to a different reference frame. If the new frame is not inertial, an exception will be thrown.

Specified by:

withFrame in class FieldOrbit<T extends CalculusFieldElement<T>>

Parameters:

inertialFrame - reference frame of output orbit

Returns:

orbit with different frame

shiftedBy

public FieldKeplerianOrbit<T> shiftedBy(double dt)

Get a time-shifted instance.

Specified by:

shiftedBy in interface TimeShiftable<T extends CalculusFieldElement<T>>

Parameters:

dt - time shift in seconds

Returns:

a new instance, shifted with respect to instance (which is not changed)

shiftedBy

public FieldKeplerianOrbit<T> shiftedBy(T dt)

Get a time-shifted orbit.

The orbit can be slightly shifted to close dates. This shift is based on a simple Keplerian model. It is not intended as a replacement for proper orbit and attitude propagation but should be sufficient for small time shifts or coarse accuracy.

Specified by:

shiftedBy in interface FieldTimeShiftable<FieldOrbit<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Specified by:

shiftedBy in class FieldOrbit<T extends CalculusFieldElement<T>>

Parameters:

dt - time shift in seconds

Returns:

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

computeJacobianMeanWrtCartesian

protected T[][] computeJacobianMeanWrtCartesian()

Compute the Jacobian of the orbital parameters with mean angle with respect to the Cartesian parameters.

Element jacobian[i][j] is the derivative of parameter i of the orbit with respect to Cartesian coordinate j. This means each row correspond to one orbital parameter whereas columns 0 to 5 correspond to the Cartesian coordinates x, y, z, xDot, yDot and zDot.

Specified by:

computeJacobianMeanWrtCartesian in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

6x6 Jacobian matrix

See Also:

FieldOrbit.computeJacobianEccentricWrtCartesian(), FieldOrbit.computeJacobianTrueWrtCartesian()

computeJacobianEccentricWrtCartesian

protected T[][] computeJacobianEccentricWrtCartesian()

Compute the Jacobian of the orbital parameters with eccentric angle with respect to the Cartesian parameters.

Element jacobian[i][j] is the derivative of parameter i of the orbit with respect to Cartesian coordinate j. This means each row correspond to one orbital parameter whereas columns 0 to 5 correspond to the Cartesian coordinates x, y, z, xDot, yDot and zDot.

Specified by:

computeJacobianEccentricWrtCartesian in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

6x6 Jacobian matrix

See Also:

FieldOrbit.computeJacobianMeanWrtCartesian(), FieldOrbit.computeJacobianTrueWrtCartesian()

computeJacobianTrueWrtCartesian

protected T[][] computeJacobianTrueWrtCartesian()

Compute the Jacobian of the orbital parameters with true angle with respect to the Cartesian parameters.

Element jacobian[i][j] is the derivative of parameter i of the orbit with respect to Cartesian coordinate j. This means each row correspond to one orbital parameter whereas columns 0 to 5 correspond to the Cartesian coordinates x, y, z, xDot, yDot and zDot.

Specified by:

computeJacobianTrueWrtCartesian in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

6x6 Jacobian matrix

See Also:

FieldOrbit.computeJacobianMeanWrtCartesian(), FieldOrbit.computeJacobianEccentricWrtCartesian()

addKeplerContribution

public void addKeplerContribution(PositionAngleType type,
                                  T gm,
                                  T[] pDot)

Add the contribution of the Keplerian motion to parameters derivatives

This method is used by integration-based propagators to evaluate the part of Keplerian motion to evolution of the orbital state.

Specified by:

addKeplerContribution in class FieldOrbit<T extends CalculusFieldElement<T>>

Parameters:

type - type of the position angle in the state

gm - attraction coefficient to use

pDot - array containing orbital state derivatives to update (the Keplerian part must be added to the array components, as the array may already contain some non-zero elements corresponding to non-Keplerian parts)

toString

public String toString()

Returns a string representation of this Keplerian parameters object.

Overrides:

toString in class Object

Returns:

a string representation of this object

getCachedPositionAngleType

public PositionAngleType getCachedPositionAngleType()

Get the cached PositionAngleType.

Specified by:

getCachedPositionAngleType in interface PositionAngleBased

Returns:

cached type of position angle

hasNonKeplerianRates

public boolean hasNonKeplerianRates()

Tells whether the instance holds rates (first-order time derivatives) for dependent variables that are incompatible with Keplerian motion.

Specified by:

hasNonKeplerianRates in interface PositionAngleBased

Returns:

true if and only if holding non-Keplerian rates

withKeplerianRates

public FieldKeplerianOrbit<T> withKeplerianRates()

Create a new instance such that PositionAngleBased.hasNonKeplerianRates() is false.

Specified by:

withKeplerianRates in interface PositionAngleBased

Returns:

new object without rates

toOrbit

public KeplerianOrbit toOrbit()

Transforms the FieldOrbit instance into an Orbit instance.

Specified by:

toOrbit in class FieldOrbit<T extends CalculusFieldElement<T>>

Returns:

Orbit instance with same properties