Class KeplerianOrbit
- java.lang.Object
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- org.orekit.orbits.Orbit
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- org.orekit.orbits.KeplerianOrbit
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- All Implemented Interfaces:
Serializable
,PositionAngleBased
,TimeShiftable<Orbit>
,TimeStamped
,PVCoordinatesProvider
public class KeplerianOrbit extends Orbit 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.- Author:
- Luc Maisonobe, Guylaine Prat, Fabien Maussion, Véronique Pommier-Maurussane
- See Also:
Orbit
,CircularOrbit
,CartesianOrbit
,EquinoctialOrbit
, Serialized Form
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Constructor Summary
Constructors Constructor Description KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, double aDot, double eDot, double iDot, double paDot, double raanDot, double anomalyDot, PositionAngleType type, Frame frame, AbsoluteDate date, double mu)
Creates a new instance with cached position angle same as value inputted.KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, double aDot, double eDot, double iDot, double paDot, double raanDot, double anomalyDot, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, AbsoluteDate date, double mu)
Creates a new instance.KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, PositionAngleType type, Frame frame, AbsoluteDate date, double mu)
Creates a new instance without derivatives and with cached position angle same as value inputted.KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, AbsoluteDate date, double mu)
Creates a new instance.KeplerianOrbit(Orbit op)
Constructor from any kind of orbital parameters.KeplerianOrbit(PVCoordinates pvCoordinates, Frame frame, AbsoluteDate date, double mu)
Constructor from Cartesian parameters.KeplerianOrbit(TimeStampedPVCoordinates pvCoordinates, Frame frame, double mu)
Constructor from Cartesian parameters.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
addKeplerContribution(PositionAngleType type, double gm, double[] pDot)
Add the contribution of the Keplerian motion to parameters derivativesprotected double[][]
computeJacobianEccentricWrtCartesian()
Compute the Jacobian of the orbital parameters with eccentric angle with respect to the Cartesian parameters.protected double[][]
computeJacobianMeanWrtCartesian()
Compute the Jacobian of the orbital parameters with mean angle with respect to the Cartesian parameters.protected double[][]
computeJacobianTrueWrtCartesian()
Compute the Jacobian of the orbital parameters with true angle with respect to the Cartesian parameters.double
getA()
Get the semi-major axis.double
getADot()
Get the semi-major axis derivative.double
getAnomaly(PositionAngleType type)
Get the anomaly.double
getAnomalyDot(PositionAngleType type)
Get the anomaly derivative.PositionAngleType
getCachedPositionAngleType()
Get the cachedPositionAngleType
.double
getE()
Get the eccentricity.double
getEccentricAnomaly()
Get the eccentric anomaly.double
getEccentricAnomalyDot()
Get the eccentric anomaly derivative.double
getEDot()
Get the eccentricity derivative.double
getEquinoctialEx()
Get the first component of the equinoctial eccentricity vector.double
getEquinoctialExDot()
Get the first component of the equinoctial eccentricity vector derivative.double
getEquinoctialEy()
Get the second component of the equinoctial eccentricity vector.double
getEquinoctialEyDot()
Get the second component of the equinoctial eccentricity vector derivative.double
getHx()
Get the first component of the inclination vector.double
getHxDot()
Get the first component of the inclination vector derivative.double
getHy()
Get the second component of the inclination vector.double
getHyDot()
Get the second component of the inclination vector derivative.double
getI()
Get the inclination.double
getIDot()
Get the inclination derivative.double
getLE()
Get the eccentric longitude argument.double
getLEDot()
Get the eccentric longitude argument derivative.double
getLM()
Get the mean longitude argument.double
getLMDot()
Get the mean longitude argument derivative.double
getLv()
Get the true longitude argument.double
getLvDot()
Get the true longitude argument derivative.double
getMeanAnomaly()
Get the mean anomaly.double
getMeanAnomalyDot()
Get the mean anomaly derivative.double
getPerigeeArgument()
Get the perigee argument.double
getPerigeeArgumentDot()
Get the perigee argument derivative.double
getRightAscensionOfAscendingNode()
Get the right ascension of the ascending node.double
getRightAscensionOfAscendingNodeDot()
Get the right ascension of the ascending node derivative.double
getTrueAnomaly()
Get the true anomaly.double
getTrueAnomalyDot()
Get the true anomaly derivative.OrbitType
getType()
Get the orbit type.boolean
hasRates()
Tells whether the instance holds rates (first-order time derivatives) for dependent variables.protected Vector3D
initPosition()
Compute the position coordinates from the canonical parameters.protected TimeStampedPVCoordinates
initPVCoordinates()
Compute the position/velocity coordinates from the canonical parameters.KeplerianOrbit
removeRates()
Create a new instance such thatPositionAngleBased.hasRates()
is false.KeplerianOrbit
shiftedBy(double dt)
Get a time-shifted orbit.String
toString()
Returns a string representation of this Keplerian parameters object.-
Methods inherited from class org.orekit.orbits.Orbit
fillHalfRow, fillHalfRow, fillHalfRow, fillHalfRow, fillHalfRow, fillHalfRow, getDate, getFrame, getJacobianWrtCartesian, getJacobianWrtParameters, getKeplerianMeanMotion, getKeplerianPeriod, getMeanAnomalyDotWrtA, getMu, getPosition, getPosition, getPosition, getPVCoordinates, getPVCoordinates, getPVCoordinates, hasDerivatives, hasNonKeplerianAcceleration, isElliptical
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.orekit.time.TimeStamped
durationFrom
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Constructor Detail
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KeplerianOrbit
public KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, AbsoluteDate date, double mu) throws IllegalArgumentException
Creates a new instance.- Parameters:
a
- semi-major axis (m), negative for hyperbolic orbitse
- 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 anomalycachedPositionAngleType
- type of cached anomalyframe
- the frame in which the parameters are defined (must be apseudo-inertial frame
)date
- date of the orbital parametersmu
- central attraction coefficient (m³/s²)- Throws:
IllegalArgumentException
- if frame is not apseudo-inertial frame
or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits- Since:
- 12.1
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KeplerianOrbit
public KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, PositionAngleType type, Frame frame, AbsoluteDate date, double mu) throws IllegalArgumentException
Creates a new instance without derivatives and with cached position angle same as value inputted.- Parameters:
a
- semi-major axis (m), negative for hyperbolic orbitse
- 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 anomalyframe
- the frame in which the parameters are defined (must be apseudo-inertial frame
)date
- date of the orbital parametersmu
- central attraction coefficient (m³/s²)- Throws:
IllegalArgumentException
- if frame is not apseudo-inertial frame
or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits
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KeplerianOrbit
public KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, double aDot, double eDot, double iDot, double paDot, double raanDot, double anomalyDot, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, AbsoluteDate date, double mu) throws IllegalArgumentException
Creates a new instance.- Parameters:
a
- semi-major axis (m), negative for hyperbolic orbitse
- 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 (m/s)eDot
- eccentricity derivativeiDot
- inclination derivative (rad/s)paDot
- perigee argument derivative (rad/s)raanDot
- right ascension of ascending node derivative (rad/s)anomalyDot
- mean, eccentric or true anomaly derivative (rad/s)type
- type of input anomalycachedPositionAngleType
- type of cached anomalyframe
- the frame in which the parameters are defined (must be apseudo-inertial frame
)date
- date of the orbital parametersmu
- central attraction coefficient (m³/s²)- Throws:
IllegalArgumentException
- if frame is not apseudo-inertial frame
or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits- Since:
- 12.1
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KeplerianOrbit
public KeplerianOrbit(double a, double e, double i, double pa, double raan, double anomaly, double aDot, double eDot, double iDot, double paDot, double raanDot, double anomalyDot, PositionAngleType type, Frame frame, AbsoluteDate date, double mu) throws IllegalArgumentException
Creates a new instance with cached position angle same as value inputted.- Parameters:
a
- semi-major axis (m), negative for hyperbolic orbitse
- 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 (m/s)eDot
- eccentricity derivativeiDot
- inclination derivative (rad/s)paDot
- perigee argument derivative (rad/s)raanDot
- right ascension of ascending node derivative (rad/s)anomalyDot
- mean, eccentric or true anomaly derivative (rad/s)type
- type of anomalyframe
- the frame in which the parameters are defined (must be apseudo-inertial frame
)date
- date of the orbital parametersmu
- central attraction coefficient (m³/s²)- Throws:
IllegalArgumentException
- if frame is not apseudo-inertial frame
or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits- Since:
- 9.0
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KeplerianOrbit
public KeplerianOrbit(TimeStampedPVCoordinates pvCoordinates, Frame frame, double mu) throws IllegalArgumentException
Constructor from Cartesian parameters.The acceleration provided in
pvCoordinates
is accessible usingOrbit.getPVCoordinates()
andOrbit.getPVCoordinates(Frame)
. All other methods usemu
and the position to compute the acceleration, includingshiftedBy(double)
andOrbit.getPVCoordinates(AbsoluteDate, Frame)
.- Parameters:
pvCoordinates
- the PVCoordinates of the satelliteframe
- the frame in which are defined thePVCoordinates
(must be apseudo-inertial frame
)mu
- central attraction coefficient (m³/s²)- Throws:
IllegalArgumentException
- if frame is not apseudo-inertial frame
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KeplerianOrbit
public KeplerianOrbit(PVCoordinates pvCoordinates, Frame frame, AbsoluteDate date, double mu) throws IllegalArgumentException
Constructor from Cartesian parameters.The acceleration provided in
pvCoordinates
is accessible usingOrbit.getPVCoordinates()
andOrbit.getPVCoordinates(Frame)
. All other methods usemu
and the position to compute the acceleration, includingshiftedBy(double)
andOrbit.getPVCoordinates(AbsoluteDate, Frame)
.- Parameters:
pvCoordinates
- the PVCoordinates of the satelliteframe
- the frame in which are defined thePVCoordinates
(must be apseudo-inertial frame
)date
- date of the orbital parametersmu
- central attraction coefficient (m³/s²)- Throws:
IllegalArgumentException
- if frame is not apseudo-inertial frame
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KeplerianOrbit
public KeplerianOrbit(Orbit op)
Constructor from any kind of orbital parameters.- Parameters:
op
- orbital parameters to copy
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Method Detail
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getType
public OrbitType getType()
Get the orbit type.
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getA
public double getA()
Get the semi-major axis.Note that the semi-major axis is considered negative for hyperbolic orbits.
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getADot
public double 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
Double.NaN
.- Specified by:
getADot
in classOrbit
- Returns:
- semi-major axis derivative (m/s)
- See Also:
Orbit.hasDerivatives()
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getE
public double getE()
Get the eccentricity.
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getEDot
public double getEDot()
Get the eccentricity derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getEDot
in classOrbit
- Returns:
- eccentricity derivative
- See Also:
Orbit.hasDerivatives()
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getI
public double getI()
Get the inclination.
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getIDot
public double getIDot()
Get the inclination derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getIDot
in classOrbit
- Returns:
- inclination derivative (rad/s)
- See Also:
Orbit.hasDerivatives()
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getPerigeeArgument
public double getPerigeeArgument()
Get the perigee argument.- Returns:
- perigee argument (rad)
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getPerigeeArgumentDot
public double getPerigeeArgumentDot()
Get the perigee argument derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Returns:
- perigee argument derivative (rad/s)
- Since:
- 9.0
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getRightAscensionOfAscendingNode
public double getRightAscensionOfAscendingNode()
Get the right ascension of the ascending node.- Returns:
- right ascension of the ascending node (rad)
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getRightAscensionOfAscendingNodeDot
public double getRightAscensionOfAscendingNodeDot()
Get the right ascension of the ascending node derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Returns:
- right ascension of the ascending node derivative (rad/s)
- Since:
- 9.0
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getTrueAnomaly
public double getTrueAnomaly()
Get the true anomaly.- Returns:
- true anomaly (rad)
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getTrueAnomalyDot
public double getTrueAnomalyDot()
Get the true anomaly derivative.- Returns:
- true anomaly derivative (rad/s)
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getEccentricAnomaly
public double getEccentricAnomaly()
Get the eccentric anomaly.- Returns:
- eccentric anomaly (rad)
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getEccentricAnomalyDot
public double getEccentricAnomalyDot()
Get the eccentric anomaly derivative.- Returns:
- eccentric anomaly derivative (rad/s)
- Since:
- 9.0
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getMeanAnomaly
public double getMeanAnomaly()
Get the mean anomaly.- Returns:
- mean anomaly (rad)
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getMeanAnomalyDot
public double getMeanAnomalyDot()
Get the mean anomaly derivative.- Returns:
- mean anomaly derivative (rad/s)
- Since:
- 9.0
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getAnomaly
public double getAnomaly(PositionAngleType type)
Get the anomaly.- Parameters:
type
- type of the angle- Returns:
- anomaly (rad)
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getAnomalyDot
public double getAnomalyDot(PositionAngleType type)
Get the anomaly derivative.- Parameters:
type
- type of the angle- Returns:
- anomaly derivative (rad/s)
- Since:
- 9.0
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getEquinoctialEx
public double getEquinoctialEx()
Get the first component of the equinoctial eccentricity vector.- Specified by:
getEquinoctialEx
in classOrbit
- Returns:
- first component of the equinoctial eccentricity vector
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getEquinoctialExDot
public double getEquinoctialExDot()
Get the first component of the equinoctial eccentricity vector derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getEquinoctialExDot
in classOrbit
- Returns:
- first component of the equinoctial eccentricity vector derivative
- See Also:
Orbit.hasDerivatives()
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getEquinoctialEy
public double getEquinoctialEy()
Get the second component of the equinoctial eccentricity vector.- Specified by:
getEquinoctialEy
in classOrbit
- Returns:
- second component of the equinoctial eccentricity vector
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getEquinoctialEyDot
public double getEquinoctialEyDot()
Get the second component of the equinoctial eccentricity vector derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getEquinoctialEyDot
in classOrbit
- Returns:
- second component of the equinoctial eccentricity vector derivative
- See Also:
Orbit.hasDerivatives()
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getHx
public double getHx()
Get the first component of the inclination vector.
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getHxDot
public double getHxDot()
Get the first component of the inclination vector derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getHxDot
in classOrbit
- Returns:
- first component of the inclination vector derivative
- See Also:
Orbit.hasDerivatives()
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getHy
public double getHy()
Get the second component of the inclination vector.
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getHyDot
public double getHyDot()
Get the second component of the inclination vector derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getHyDot
in classOrbit
- Returns:
- second component of the inclination vector derivative
- See Also:
Orbit.hasDerivatives()
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getLv
public double getLv()
Get the true longitude argument.
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getLvDot
public double getLvDot()
Get the true longitude argument derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getLvDot
in classOrbit
- Returns:
- d(v + ω + Ω)/dt true longitude argument derivative (rad/s)
- See Also:
Orbit.hasDerivatives()
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getLE
public double getLE()
Get the eccentric longitude argument.
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getLEDot
public double getLEDot()
Get the eccentric longitude argument derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getLEDot
in classOrbit
- Returns:
- d(E + ω + Ω)/dt eccentric longitude argument derivative (rad/s)
- See Also:
Orbit.hasDerivatives()
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getLM
public double getLM()
Get the mean longitude argument.
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getLMDot
public double getLMDot()
Get the mean longitude argument derivative.If the orbit was created without derivatives, the value returned is
Double.NaN
.- Specified by:
getLMDot
in classOrbit
- Returns:
- d(M + ω + Ω)/dt mean longitude argument derivative (rad/s)
- See Also:
Orbit.hasDerivatives()
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initPosition
protected Vector3D initPosition()
Compute the position coordinates from the canonical parameters.- Specified by:
initPosition
in classOrbit
- Returns:
- computed position coordinates
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initPVCoordinates
protected TimeStampedPVCoordinates initPVCoordinates()
Compute the position/velocity coordinates from the canonical parameters.- Specified by:
initPVCoordinates
in classOrbit
- Returns:
- computed position/velocity coordinates
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shiftedBy
public KeplerianOrbit shiftedBy(double dt)
Get a time-shifted orbit.The orbit can be slightly shifted to close dates. The shifting model is a Keplerian one if no derivatives are available in the orbit, or Keplerian plus quadratic effect of the non-Keplerian acceleration if derivatives are available. Shifting is not intended as a replacement for proper orbit propagation but should be sufficient for small time shifts or coarse accuracy.
- Specified by:
shiftedBy
in interfaceTimeShiftable<Orbit>
- Specified by:
shiftedBy
in classOrbit
- Parameters:
dt
- time shift in seconds- Returns:
- a new orbit, shifted with respect to the instance (which is immutable)
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computeJacobianMeanWrtCartesian
protected double[][] 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.The array returned by this method will not be modified.
- Specified by:
computeJacobianMeanWrtCartesian
in classOrbit
- Returns:
- 6x6 Jacobian matrix
- See Also:
Orbit.computeJacobianEccentricWrtCartesian()
,Orbit.computeJacobianTrueWrtCartesian()
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computeJacobianEccentricWrtCartesian
protected double[][] 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.The array returned by this method will not be modified.
- Specified by:
computeJacobianEccentricWrtCartesian
in classOrbit
- Returns:
- 6x6 Jacobian matrix
- See Also:
Orbit.computeJacobianMeanWrtCartesian()
,Orbit.computeJacobianTrueWrtCartesian()
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computeJacobianTrueWrtCartesian
protected double[][] 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.The array returned by this method will not be modified.
- Specified by:
computeJacobianTrueWrtCartesian
in classOrbit
- Returns:
- 6x6 Jacobian matrix
- See Also:
Orbit.computeJacobianMeanWrtCartesian()
,Orbit.computeJacobianEccentricWrtCartesian()
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addKeplerContribution
public void addKeplerContribution(PositionAngleType type, double gm, double[] pDot)
Add the contribution of the Keplerian motion to parameters derivativesThis method is used by integration-based propagators to evaluate the part of Keplerian motion to evolution of the orbital state.
- Specified by:
addKeplerContribution
in classOrbit
- Parameters:
type
- type of the position angle in the stategm
- attraction coefficient to usepDot
- 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)
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toString
public String toString()
Returns a string representation of this Keplerian parameters object.
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getCachedPositionAngleType
public PositionAngleType getCachedPositionAngleType()
Get the cachedPositionAngleType
.- Specified by:
getCachedPositionAngleType
in interfacePositionAngleBased
- Returns:
- cached type of position angle
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hasRates
public boolean hasRates()
Tells whether the instance holds rates (first-order time derivatives) for dependent variables.- Specified by:
hasRates
in interfacePositionAngleBased
- Returns:
- true if and only if holding rates
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removeRates
public KeplerianOrbit removeRates()
Create a new instance such thatPositionAngleBased.hasRates()
is false.- Specified by:
removeRates
in interfacePositionAngleBased
- Returns:
- new object without rates
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