Package org.orekit.orbits

Class FieldCircularOrbit<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.orbits.FieldOrbit<T>

org.orekit.orbits.FieldCircularOrbit<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 FieldCircularOrbit<T extends CalculusFieldElement<T>>
extends FieldOrbit<T>
implements PositionAngleBased

This class handles circular orbital parameters.

The parameters used internally are the circular elements which can be related to Keplerian elements as follows:

• a
• e_x = e cos(ω)
• e_y = e sin(ω)
• i
• Ω
• α_v = v + ω

where Ω stands for the Right Ascension of the Ascending Node and α_v stands for the true latitude argument

The conversion equations from and to Keplerian elements given above hold only when both sides are unambiguously defined, i.e. when orbit is neither equatorial nor circular. When orbit is circular (but not equatorial), the circular parameters are still unambiguously defined whereas some Keplerian elements (more precisely ω and Ω) become ambiguous. When orbit is equatorial, neither the Keplerian nor the circular parameters can be defined unambiguously. equinoctial orbits is the recommended way to represent orbits.

The instance CircularOrbit is guaranteed to be immutable.

Since:

9.0

Author:

Luc Maisonobe, Fabien Maussion, Véronique Pommier-Maurussane

See Also:

Orbit, KeplerianOrbit, CartesianOrbit, EquinoctialOrbit

Constructor Summary

Constructors

Constructor	Description
FieldCircularOrbit(Field<T> field, CircularOrbit op)	Constructor from Field and CircularOrbit.
FieldCircularOrbit(Field<T> field, Orbit op)	Constructor from Field and Orbit.
FieldCircularOrbit(FieldOrbit<T> op)	Constructor from any kind of orbital parameters.
FieldCircularOrbit(FieldPVCoordinates<T> PVCoordinates, Frame frame, FieldAbsoluteDate<T> date, T mu)	Constructor from Cartesian parameters.
FieldCircularOrbit(TimeStampedFieldPVCoordinates<T> pvCoordinates, Frame frame, T mu)	Constructor from Cartesian parameters.
FieldCircularOrbit(T a, T ex, T ey, T i, T raan, T alpha, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance without derivatives and with cached position angle same as value inputted.
FieldCircularOrbit(T a, T ex, T ey, T i, T raan, T alpha, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldCircularOrbit(T a, T ex, T ey, T i, T raan, T alpha, T aDot, T exDot, T eyDot, T iDot, T raanDot, T alphaDot, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldCircularOrbit(T a, T ex, T ey, T i, T raan, T alpha, T aDot, T exDot, T eyDot, T iDot, T raanDot, T alphaDot, 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.
static <T extends CalculusFieldElement<T>> T	eccentricToMean(T alphaE, T ex, T ey)	Deprecated.
static <T extends CalculusFieldElement<T>> T	eccentricToTrue(T alphaE, T ex, T ey)	Deprecated.
T	getA()	Get the semi-major axis.
T	getADot()	Get the semi-major axis derivative.
T	getAlpha(PositionAngleType type)	Get the latitude argument.
T	getAlphaDot(PositionAngleType type)	Get the latitude argument derivative.
T	getAlphaE()	Get the eccentric latitude argument.
T	getAlphaEDot()	Get the eccentric latitude argument derivative.
T	getAlphaM()	Get the mean latitude argument.
T	getAlphaMDot()	Get the mean latitude argument derivative.
T	getAlphaV()	Get the true latitude argument.
T	getAlphaVDot()	Get the true latitude argument derivative.
PositionAngleType	getCachedPositionAngleType()	Get the cached PositionAngleType.
T	getCircularEx()	Get the first component of the circular eccentricity vector.
T	getCircularExDot()	Get the first component of the circular eccentricity vector derivative.
T	getCircularEy()	Get the second component of the circular eccentricity vector.
T	getCircularEyDot()	Get the second component of the circular eccentricity vector derivative.
T	getE()	Get the eccentricity.
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	getRightAscensionOfAscendingNode()	Get the right ascension of the ascending node.
T	getRightAscensionOfAscendingNodeDot()	Get the right ascension of the ascending node derivative.
OrbitType	getType()	Get the orbit type.
boolean	hasDerivatives()	Check if orbit includes derivatives.
boolean	hasRates()	Tells whether the instance holds rates (first-order time derivatives) for dependent variables.
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.
static <T extends CalculusFieldElement<T>> T	meanToEccentric(T alphaM, T ex, T ey)	Deprecated.
FieldCircularOrbit<T>	removeRates()	Create a new instance such that PositionAngleBased.hasRates() is false.
FieldCircularOrbit<T>	shiftedBy(double dt)	Get a time-shifted instance.
FieldCircularOrbit<T>	shiftedBy(T dt)	Get a time-shifted orbit.
CircularOrbit	toOrbit()	Transforms the FieldOrbit instance into an Orbit instance.
String	toString()	Returns a string representation of this Orbit object.
static <T extends CalculusFieldElement<T>> T	trueToEccentric(T alphaV, T ex, T ey)	Deprecated.

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

Constructor Detail

FieldCircularOrbit

public FieldCircularOrbit(T a,
                          T ex,
                          T ey,
                          T i,
                          T raan,
                          T alpha,
                          PositionAngleType type,
                          PositionAngleType cachedPositionAngleType,
                          Frame frame,
                          FieldAbsoluteDate<T> date,
                          T mu)
                   throws IllegalArgumentException

Creates a new instance.

Parameters:

a - semi-major axis (m)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

i - inclination (rad)

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

alpha - an + ω, mean, eccentric or true latitude argument (rad)

type - type of latitude argument

cachedPositionAngleType - type of cached latitude argument

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

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if eccentricity is equal to 1 or larger or if frame is not a pseudo-inertial frame

Since:

12.1

FieldCircularOrbit

public FieldCircularOrbit(T a,
                          T ex,
                          T ey,
                          T i,
                          T raan,
                          T alpha,
                          PositionAngleType type,
                          Frame frame,
                          FieldAbsoluteDate<T> date,
                          T mu)
                   throws IllegalArgumentException

Creates a new instance without derivatives and with cached position angle same as value inputted.

Parameters:

a - semi-major axis (m)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

i - inclination (rad)

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

alpha - an + ω, mean, eccentric or true latitude argument (rad)

type - type of latitude argument

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

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if eccentricity is equal to 1 or larger or if frame is not a pseudo-inertial frame

FieldCircularOrbit

public FieldCircularOrbit(T a,
                          T ex,
                          T ey,
                          T i,
                          T raan,
                          T alpha,
                          T aDot,
                          T exDot,
                          T eyDot,
                          T iDot,
                          T raanDot,
                          T alphaDot,
                          PositionAngleType type,
                          Frame frame,
                          FieldAbsoluteDate<T> date,
                          T mu)
                   throws IllegalArgumentException

Creates a new instance.

Parameters:

a - semi-major axis (m)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

i - inclination (rad)

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

alpha - an + ω, mean, eccentric or true latitude argument (rad)

aDot - semi-major axis derivative (m/s)

exDot - d(e cos(ω))/dt, first component of circular eccentricity vector derivative

eyDot - d(e sin(ω))/dt, second component of circular eccentricity vector derivative

iDot - inclination derivative(rad/s)

raanDot - right ascension of ascending node derivative (rad/s)

alphaDot - d(an + ω), mean, eccentric or true latitude argument derivative (rad/s)

type - type of latitude argument

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

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if eccentricity is equal to 1 or larger or if frame is not a pseudo-inertial frame

FieldCircularOrbit

public FieldCircularOrbit(T a,
                          T ex,
                          T ey,
                          T i,
                          T raan,
                          T alpha,
                          T aDot,
                          T exDot,
                          T eyDot,
                          T iDot,
                          T raanDot,
                          T alphaDot,
                          PositionAngleType type,
                          PositionAngleType cachedPositionAngleType,
                          Frame frame,
                          FieldAbsoluteDate<T> date,
                          T mu)
                   throws IllegalArgumentException

Creates a new instance.

Parameters:

a - semi-major axis (m)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

i - inclination (rad)

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

alpha - an + ω, mean, eccentric or true latitude argument (rad)

aDot - semi-major axis derivative (m/s)

exDot - d(e cos(ω))/dt, first component of circular eccentricity vector derivative

eyDot - d(e sin(ω))/dt, second component of circular eccentricity vector derivative

iDot - inclination derivative(rad/s)

raanDot - right ascension of ascending node derivative (rad/s)

alphaDot - d(an + ω), mean, eccentric or true latitude argument derivative (rad/s)

type - type of latitude argument

cachedPositionAngleType - type of cached latitude argument

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

date - date of the orbital parameters

mu - central attraction coefficient (m³/s²)

Throws:

IllegalArgumentException - if eccentricity is equal to 1 or larger or if frame is not a pseudo-inertial frame

Since:

12.1

FieldCircularOrbit

public FieldCircularOrbit(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 FieldPVCoordinates in inertial frame

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

FieldCircularOrbit

public FieldCircularOrbit(FieldPVCoordinates<T> PVCoordinates,
                          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:

PVCoordinates - the FieldPVCoordinates in inertial frame

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

FieldCircularOrbit

public FieldCircularOrbit(FieldOrbit<T> op)

Constructor from any kind of orbital parameters.

Parameters:

op - orbital parameters to copy

FieldCircularOrbit

public FieldCircularOrbit(Field<T> field,
                          CircularOrbit op)

Constructor from Field and CircularOrbit.

Build a FieldCircularOrbit from non-Field CircularOrbit.

Parameters:

field - CalculusField to base object on

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

Since:

12.0

FieldCircularOrbit

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

Constructor from Field and Orbit.

Build a FieldCircularOrbit 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)

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

getCircularEx

public T getCircularEx()

Get the first component of the circular eccentricity vector.

Returns:

ex = e cos(ω), first component of the circular eccentricity vector

getCircularExDot

public T getCircularExDot()

Get the first component of the circular eccentricity vector derivative.

Returns:

d(ex)/dt = d(e cos(ω))/dt, first component of the circular eccentricity vector derivative

getCircularEy

public T getCircularEy()

Get the second component of the circular eccentricity vector.

Returns:

ey = e sin(ω), second component of the circular eccentricity vector

getCircularEyDot

public T getCircularEyDot()

Get the second component of the circular eccentricity vector derivative.

Returns:

d(ey)/dt = d(e sin(ω))/dt, second component of the circular 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

getAlphaV

public T getAlphaV()

Get the true latitude argument.

Returns:

v + ω true latitude argument (rad)

getAlphaVDot

public T getAlphaVDot()

Get the true latitude argument derivative.

Returns:

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

getAlphaE

public T getAlphaE()

Get the eccentric latitude argument.

Returns:

E + ω eccentric latitude argument (rad)

getAlphaEDot

public T getAlphaEDot()

Get the eccentric latitude argument derivative.

Returns:

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

getAlphaM

public T getAlphaM()

Get the mean latitude argument.

Returns:

M + ω mean latitude argument (rad)

getAlphaMDot

public T getAlphaMDot()

Get the mean latitude argument derivative.

Returns:

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

getAlpha

public T getAlpha(PositionAngleType type)

Get the latitude argument.

Parameters:

type - type of the angle

Returns:

latitude argument (rad)

getAlphaDot

public T getAlphaDot(PositionAngleType type)

Get the latitude argument derivative.

Parameters:

type - type of the angle

Returns:

latitude argument derivative (rad/s)

eccentricToTrue

@Deprecated
public static <T extends CalculusFieldElement<T>> T eccentricToTrue(T alphaE,
                                                                    T ex,
                                                                    T ey)

Deprecated.

Computes the true latitude argument from the eccentric latitude argument.

Type Parameters:

T - Type of the field elements

Parameters:

alphaE - = E + ω eccentric latitude argument (rad)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

Returns:

the true latitude argument.

trueToEccentric

@Deprecated
public static <T extends CalculusFieldElement<T>> T trueToEccentric(T alphaV,
                                                                    T ex,
                                                                    T ey)

Deprecated.

Computes the eccentric latitude argument from the true latitude argument.

Type Parameters:

T - Type of the field elements

Parameters:

alphaV - = v + ω true latitude argument (rad)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

Returns:

the eccentric latitude argument.

meanToEccentric

@Deprecated
public static <T extends CalculusFieldElement<T>> T meanToEccentric(T alphaM,
                                                                    T ex,
                                                                    T ey)

Deprecated.

Computes the eccentric latitude argument from the mean latitude argument.

Type Parameters:

T - Type of the field elements

Parameters:

alphaM - = M + ω mean latitude argument (rad)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

Returns:

the eccentric latitude argument.

eccentricToMean

@Deprecated
public static <T extends CalculusFieldElement<T>> T eccentricToMean(T alphaE,
                                                                    T ex,
                                                                    T ey)

Deprecated.

Computes the mean latitude argument from the eccentric latitude argument.

Type Parameters:

T - Type of the field elements

Parameters:

alphaE - = E + ω eccentric latitude argument (rad)

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

Returns:

the mean latitude argument.

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)

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)

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)

hasDerivatives

public boolean hasDerivatives()

Check if orbit includes derivatives.

Specified by:

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

Returns:

true if orbit includes derivatives

See Also:

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

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

shiftedBy

public FieldCircularOrbit<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 FieldCircularOrbit<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 Orbit 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

hasRates

public boolean hasRates()

Tells whether the instance holds rates (first-order time derivatives) for dependent variables.

Specified by:

hasRates in interface PositionAngleBased

Returns:

true if and only if holding rates

removeRates

public FieldCircularOrbit<T> removeRates()

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

Specified by:

removeRates in interface PositionAngleBased

Returns:

new object without rates

toOrbit

public CircularOrbit 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