Package org.orekit.orbits

Class FieldEquinoctialOrbit<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.orbits.FieldOrbit<T>

org.orekit.orbits.FieldEquinoctialOrbit<T>

Type Parameters:

T - type of the field elements

All Implemented Interfaces:

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

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

This class handles equinoctial orbital parameters, which can support both circular and equatorial orbits.

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

     a
     ex = e cos(ω + Ω)
     ey = e sin(ω + Ω)
     hx = tan(i/2) cos(Ω)
     hy = tan(i/2) sin(Ω)
     lv = v + ω + Ω
   

where ω stands for the Perigee Argument and Ω stands for the Right Ascension of the Ascending Node.

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 either equatorial or circular, the equinoctial parameters are still unambiguously defined whereas some Keplerian elements (more precisely ω and Ω) become ambiguous. For this reason, equinoctial parameters are the recommended way to represent orbits. Note however than the present implementation does not handle non-elliptical cases.

The instance EquinoctialOrbit is guaranteed to be immutable.

Since:

9.0

Author:

Mathieu Roméro, Luc Maisonobe, Guylaine Prat, Fabien Maussion, Véronique Pommier-Maurussane

See Also:

Orbit, KeplerianOrbit, CircularOrbit, CartesianOrbit

Field Summary

Fields inherited from class org.orekit.orbits.FieldOrbit

TOLERANCE_POSITION_ANGLE_RATE

Constructor Summary

Constructors

Constructor	Description
FieldEquinoctialOrbit(Field<T> field, EquinoctialOrbit op)	Constructor from Field and EquinoctialOrbit.
FieldEquinoctialOrbit(Field<T> field, Orbit op)	Constructor from Field and Orbit.
FieldEquinoctialOrbit(FieldOrbit<T> op)	Constructor from any kind of orbital parameters.
FieldEquinoctialOrbit(FieldPVCoordinates<T> pvCoordinates, Frame frame, FieldAbsoluteDate<T> date, T mu)	Constructor from Cartesian parameters.
FieldEquinoctialOrbit(TimeStampedFieldPVCoordinates<T> pvCoordinates, Frame frame, T mu)	Constructor from Cartesian parameters.
FieldEquinoctialOrbit(T a, T ex, T ey, T hx, T hy, T l, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldEquinoctialOrbit(T a, T ex, T ey, T hx, T hy, T l, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldEquinoctialOrbit(T a, T ex, T ey, T hx, T hy, T l, T aDot, T exDot, T eyDot, T hxDot, T hyDot, T lDot, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu)	Creates a new instance.
FieldEquinoctialOrbit(T a, T ex, T ey, T hx, T hy, T l, T aDot, T exDot, T eyDot, T hxDot, T hyDot, T lDot, 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.
PositionAngleType	getCachedPositionAngleType()	Get the cached PositionAngleType.
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	getL(PositionAngleType type)	Get the longitude argument.
T	getLDot(PositionAngleType type)	Get the longitude argument 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.
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.
FieldEquinoctialOrbit<T>	inFrame(Frame inertialFrame)	Create a new object representing the same physical orbital state, but attached to a different reference frame.
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.
FieldEquinoctialOrbit<T>	shiftedBy(double dt)	Get a time-shifted orbit.
FieldEquinoctialOrbit<T>	shiftedBy(TimeOffset dt)	Get a time-shifted instance.
FieldEquinoctialOrbit<T>	shiftedBy(T dt)	Get a time-shifted orbit.
EquinoctialOrbit	toOrbit()	Transforms the FieldOrbit instance into an Orbit instance.
String	toString()	Returns a string representation of this equinoctial parameters object.
FieldEquinoctialOrbit<T>	withCachedPositionAngleType(PositionAngleType positionAngleType)	Creates a new instance with the provided type used for caching.
FieldEquinoctialOrbit<T>	withKeplerianRates()	Creates a new instance such that PositionAngleBased.hasNonKeplerianRates() is false.

Methods inherited from class org.orekit.orbits.FieldOrbit

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

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, durationFrom

Methods inherited from interface org.orekit.utils.ShiftableFieldPVCoordinatesHolder

getPosition, getPosition, getPVCoordinates, getVelocity, getVelocity, getVelocity

Constructor Detail

FieldEquinoctialOrbit

public FieldEquinoctialOrbit(T a,
                             T ex,
                             T ey,
                             T hx,
                             T hy,
                             T l,
                             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 + Ω), first component of eccentricity vector

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

hx - tan(i/2) cos(Ω), first component of inclination vector

hy - tan(i/2) sin(Ω), second component of inclination vector

l - (M or E or v) + ω + Ω, mean, eccentric or true longitude argument (rad)

type - type of longitude argument

cachedPositionAngleType - type of cached longitude argument

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

Since:

12.1

FieldEquinoctialOrbit

public FieldEquinoctialOrbit(T a,
                             T ex,
                             T ey,
                             T hx,
                             T hy,
                             T l,
                             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 + Ω), first component of eccentricity vector

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

hx - tan(i/2) cos(Ω), first component of inclination vector

hy - tan(i/2) sin(Ω), second component of inclination vector

l - (M or E or v) + ω + Ω, mean, eccentric or true longitude argument (rad)

type - type of longitude argument

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

FieldEquinoctialOrbit

public FieldEquinoctialOrbit(T a,
                             T ex,
                             T ey,
                             T hx,
                             T hy,
                             T l,
                             T aDot,
                             T exDot,
                             T eyDot,
                             T hxDot,
                             T hyDot,
                             T lDot,
                             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 + Ω), first component of eccentricity vector

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

hx - tan(i/2) cos(Ω), first component of inclination vector

hy - tan(i/2) sin(Ω), second component of inclination vector

l - (M or E or v) + ω + Ω, mean, eccentric or true longitude argument (rad)

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

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

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

hxDot - d(tan(i/2) cos(Ω))/dt, first component of inclination vector derivative

hyDot - d(tan(i/2) sin(Ω))/dt, second component of inclination vector derivative

lDot - d(M or E or v) + ω + Ω)/dr, mean, eccentric or true longitude argument derivative (rad/s)

type - type of longitude argument

cachedPositionAngleType - of cached longitude argument

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

Since:

12.1

FieldEquinoctialOrbit

public FieldEquinoctialOrbit(T a,
                             T ex,
                             T ey,
                             T hx,
                             T hy,
                             T l,
                             T aDot,
                             T exDot,
                             T eyDot,
                             T hxDot,
                             T hyDot,
                             T lDot,
                             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 + Ω), first component of eccentricity vector

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

hx - tan(i/2) cos(Ω), first component of inclination vector

hy - tan(i/2) sin(Ω), second component of inclination vector

l - (M or E or v) + ω + Ω, mean, eccentric or true longitude argument (rad)

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

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

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

hxDot - d(tan(i/2) cos(Ω))/dt, first component of inclination vector derivative

hyDot - d(tan(i/2) sin(Ω))/dt, second component of inclination vector derivative

lDot - d(M or E or v) + ω + Ω)/dr, mean, eccentric or true longitude argument derivative (rad/s)

type - type of longitude argument

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

Since:

12.1

FieldEquinoctialOrbit

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

Constructor from Cartesian parameters.

The acceleration provided in pvCoordinates 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 ShiftableFieldPVCoordinatesHolder.getPVCoordinates(FieldAbsoluteDate, Frame).

Parameters:

pvCoordinates - the position, velocity and acceleration

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

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

FieldEquinoctialOrbit

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

Constructor from Cartesian parameters.

The acceleration provided in pvCoordinates 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 ShiftableFieldPVCoordinatesHolder.getPVCoordinates(FieldAbsoluteDate, Frame).

Parameters:

pvCoordinates - the position end velocity

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

FieldEquinoctialOrbit

public FieldEquinoctialOrbit(FieldOrbit<T> op)

Constructor from any kind of orbital parameters.

Parameters:

op - orbital parameters to copy

FieldEquinoctialOrbit

public FieldEquinoctialOrbit(Field<T> field,
                             EquinoctialOrbit op)

Constructor from Field and EquinoctialOrbit.

Build a FieldEquinoctialOrbit from non-Field EquinoctialOrbit.

Parameters:

field - CalculusField to base object on

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

Since:

12.0

FieldEquinoctialOrbit

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

Constructor from Field and Orbit.

Build a FieldEquinoctialOrbit 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

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)

getL

public T getL(PositionAngleType type)

Get the longitude argument.

Parameters:

type - type of the angle

Returns:

longitude argument (rad)

getLDot

public T getLDot(PositionAngleType type)

Get the longitude argument derivative.

Parameters:

type - type of the angle

Returns:

longitude argument 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()

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)

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

inFrame

public FieldEquinoctialOrbit<T> inFrame(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:

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

Parameters:

inertialFrame - reference frame of output orbit

Returns:

orbit with different frame

withCachedPositionAngleType

public FieldEquinoctialOrbit<T> withCachedPositionAngleType(PositionAngleType positionAngleType)

Creates a new instance with the provided type used for caching.

Specified by:

withCachedPositionAngleType in interface PositionAngleBased<T extends CalculusFieldElement<T>>

Parameters:

positionAngleType - position angle type to use for caching value

Returns:

new object

shiftedBy

public FieldEquinoctialOrbit<T> shiftedBy(double 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 TimeShiftable<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)

shiftedBy

public FieldEquinoctialOrbit<T> shiftedBy(TimeOffset dt)

Get a time-shifted instance.

Specified by:

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

Parameters:

dt - time shift

Returns:

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

shiftedBy

public FieldEquinoctialOrbit<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<ShiftableFieldPVCoordinatesHolder<FieldOrbit<T extends CalculusFieldElement<T>>,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 equinoctial 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<T extends CalculusFieldElement<T>>

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<T extends CalculusFieldElement<T>>

Returns:

true if and only if holding non-Keplerian rates

withKeplerianRates

public FieldEquinoctialOrbit<T> withKeplerianRates()

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

Specified by:

withKeplerianRates in interface PositionAngleBased<T extends CalculusFieldElement<T>>

Returns:

new object without rates

toOrbit

public EquinoctialOrbit 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