java.lang.Object
- org.orekit.orbits.Orbit
- - org.orekit.orbits.CircularOrbit

All Implemented Interfaces:

Serializable, PositionAngleBased, TimeShiftable<Orbit>, TimeStamped, PVCoordinatesProvider
```
public class CircularOrbit
extends Orbit
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.
Author:

Luc Maisonobe, Fabien Maussion, Véronique Pommier-Maurussane

See Also:

Orbit, KeplerianOrbit, CartesianOrbit, EquinoctialOrbit, Serialized Form

Constructor Summary

Constructors
Constructor	Description
`CircularOrbit(double a, double ex, double ey, double i, double raan, double alpha, double aDot, double exDot, double eyDot, double iDot, double raanDot, double alphaDot, PositionAngleType type, Frame frame, AbsoluteDate date, double mu)`	Creates a new instance with derivatives and with cached position angle same as value inputted.
`CircularOrbit(double a, double ex, double ey, double i, double raan, double alpha, double aDot, double exDot, double eyDot, double iDot, double raanDot, double alphaDot, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, AbsoluteDate date, double mu)`	Creates a new instance.
`CircularOrbit(double a, double ex, double ey, double i, double raan, double alpha, PositionAngleType type, Frame frame, AbsoluteDate date, double mu)`	Creates a new instance without derivatives and with cached position angle same as value inputted.
`CircularOrbit(double a, double ex, double ey, double i, double raan, double alpha, PositionAngleType type, PositionAngleType cachedPositionAngleType, Frame frame, AbsoluteDate date, double mu)`	Creates a new instance.
`CircularOrbit(Orbit op)`	Constructor from any kind of orbital parameters.
`CircularOrbit(PVCoordinates pvCoordinates, Frame frame, AbsoluteDate date, double mu)`	Constructor from Cartesian parameters.
`CircularOrbit(TimeStampedPVCoordinates pvCoordinates, Frame frame, double mu)`	Constructor from Cartesian parameters.

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 derivatives
`protected 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`	`getAlpha(PositionAngleType type)`	Get the latitude argument.
`double`	`getAlphaDot(PositionAngleType type)`	Get the latitude argument derivative.
`double`	`getAlphaE()`	Get the eccentric latitude argument.
`double`	`getAlphaEDot()`	Get the eccentric latitude argument derivative.
`double`	`getAlphaM()`	Get the mean latitude argument.
`double`	`getAlphaMDot()`	Get the mean latitude argument derivative.
`double`	`getAlphaV()`	Get the true latitude argument.
`double`	`getAlphaVDot()`	Get the true latitude argument derivative.
`PositionAngleType`	`getCachedPositionAngleType()`	Get the cached `PositionAngleType`.
`double`	`getCircularEx()`	Get the first component of the circular eccentricity vector.
`double`	`getCircularExDot()`	Get the first component of the circular eccentricity vector derivative.
`double`	`getCircularEy()`	Get the second component of the circular eccentricity vector.
`double`	`getCircularEyDot()`	Get the second component of the circular eccentricity vector derivative.
`double`	`getE()`	Get the eccentricity.
`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`	`getRightAscensionOfAscendingNode()`	Get the right ascension of the ascending node.
`double`	`getRightAscensionOfAscendingNodeDot()`	Get the right ascension of the ascending node 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.
`CircularOrbit`	`removeRates()`	Create a new instance such that `PositionAngleBased.hasRates()` is false.
`CircularOrbit`	`shiftedBy(double dt)`	Get a time-shifted orbit.
`CircularOrbit`	`shiftedBy(TimeOffset dt)`	Get a time-shifted orbit.
`String`	`toString()`	Returns a string representation of this Orbit 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

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.orekit.time.TimeStamped
durationFrom

- Constructor Detail
  - CircularOrbit
```
public CircularOrbit(double a,
                     double ex,
                     double ey,
                     double i,
                     double raan,
                     double alpha,
                     PositionAngleType type,
                     PositionAngleType cachedPositionAngleType,
                     Frame frame,
                     AbsoluteDate date,
                     double 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
  - CircularOrbit
```
public CircularOrbit(double a,
                     double ex,
                     double ey,
                     double i,
                     double raan,
                     double alpha,
                     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)
    
    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
  - CircularOrbit
```
public CircularOrbit(double a,
                     double ex,
                     double ey,
                     double i,
                     double raan,
                     double alpha,
                     double aDot,
                     double exDot,
                     double eyDot,
                     double iDot,
                     double raanDot,
                     double alphaDot,
                     PositionAngleType type,
                     PositionAngleType cachedPositionAngleType,
                     Frame frame,
                     AbsoluteDate date,
                     double 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
  - CircularOrbit
```
public CircularOrbit(double a,
                     double ex,
                     double ey,
                     double i,
                     double raan,
                     double alpha,
                     double aDot,
                     double exDot,
                     double eyDot,
                     double iDot,
                     double raanDot,
                     double alphaDot,
                     PositionAngleType type,
                     Frame frame,
                     AbsoluteDate date,
                     double mu)
              throws IllegalArgumentException
```
    Creates a new instance with 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)
    
    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
  - CircularOrbit
```
public CircularOrbit(TimeStampedPVCoordinates pvCoordinates,
                     Frame frame,
                     double mu)
              throws IllegalArgumentException
```
    Constructor from Cartesian parameters.
    The acceleration provided in pvCoordinates is accessible using Orbit.getPVCoordinates() and Orbit.getPVCoordinates(Frame). All other methods use mu and the position to compute the acceleration, including shiftedBy(double) and Orbit.getPVCoordinates(AbsoluteDate, Frame).
    
    Parameters:
    
    pvCoordinates - the PVCoordinates in inertial frame
    
    frame - the frame in which are defined the PVCoordinates (must be a pseudo-inertial frame)
    
    mu - central attraction coefficient (m³/s²)
    
    Throws:
    
    IllegalArgumentException - if frame is not a pseudo-inertial frame
  - CircularOrbit
```
public CircularOrbit(PVCoordinates pvCoordinates,
                     Frame frame,
                     AbsoluteDate date,
                     double mu)
              throws IllegalArgumentException
```
    Constructor from Cartesian parameters.
    The acceleration provided in pvCoordinates is accessible using Orbit.getPVCoordinates() and Orbit.getPVCoordinates(Frame). All other methods use mu and the position to compute the acceleration, including shiftedBy(double) and Orbit.getPVCoordinates(AbsoluteDate, Frame).
    
    Parameters:
    
    pvCoordinates - the PVCoordinates in inertial frame
    
    frame - the frame in which are defined the PVCoordinates (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
  - CircularOrbit
```
public CircularOrbit(Orbit op)
```
    Constructor from any kind of orbital parameters.
    
    Parameters:
    
    op - orbital parameters to copy
- Method Detail
  - getType
```
public OrbitType getType()
```
    Get the orbit type.
    
    Specified by:
    
    getType in class Orbit
    
    Returns:
    
    orbit type
  - getA
```
public double getA()
```
    Get the semi-major axis.
    Note that the semi-major axis is considered negative for hyperbolic orbits.
    
    Specified by:
    
    getA in class Orbit
    
    Returns:
    
    semi-major axis (m)
  - 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 class Orbit
    
    Returns:
    
    semi-major axis derivative (m/s)
    
    See Also:
    
    Orbit.hasDerivatives()
  - getEquinoctialEx
```
public double getEquinoctialEx()
```
    Get the first component of the equinoctial eccentricity vector.
    
    Specified by:
    
    getEquinoctialEx in class Orbit
    
    Returns:
    
    first component of the equinoctial eccentricity vector
  - 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 class Orbit
    
    Returns:
    
    first component of the equinoctial eccentricity vector derivative
    
    See Also:
    
    Orbit.hasDerivatives()
  - getEquinoctialEy
```
public double getEquinoctialEy()
```
    Get the second component of the equinoctial eccentricity vector.
    
    Specified by:
    
    getEquinoctialEy in class Orbit
    
    Returns:
    
    second component of the equinoctial eccentricity vector
  - 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 class Orbit
    
    Returns:
    
    second component of the equinoctial eccentricity vector derivative
    
    See Also:
    
    Orbit.hasDerivatives()
  - getCircularEx
```
public double getCircularEx()
```
    Get the first component of the circular eccentricity vector.
    
    Returns:
    
    ex = e cos(ω), first component of the circular eccentricity vector
  - getCircularExDot
```
public double getCircularExDot()
```
    Get the first component of the circular eccentricity vector derivative.
    
    Returns:
    
    ex = e cos(ω), first component of the circular eccentricity vector derivative
    
    Since:
    
    9.0
  - getCircularEy
```
public double getCircularEy()
```
    Get the second component of the circular eccentricity vector.
    
    Returns:
    
    ey = e sin(ω), second component of the circular eccentricity vector
  - getCircularEyDot
```
public double getCircularEyDot()
```
    Get the second component of the circular eccentricity vector derivative.
    
    Returns:
    
    ey = e sin(ω), second component of the circular eccentricity vector derivative
  - getHx
```
public double getHx()
```
    Get the first component of the inclination vector.
    
    Specified by:
    
    getHx in class Orbit
    
    Returns:
    
    first component of the inclination vector
  - 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 class Orbit
    
    Returns:
    
    first component of the inclination vector derivative
    
    See Also:
    
    Orbit.hasDerivatives()
  - getHy
```
public double getHy()
```
    Get the second component of the inclination vector.
    
    Specified by:
    
    getHy in class Orbit
    
    Returns:
    
    second component of the inclination vector
  - 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 class Orbit
    
    Returns:
    
    second component of the inclination vector derivative
    
    See Also:
    
    Orbit.hasDerivatives()
  - getAlphaV
```
public double getAlphaV()
```
    Get the true latitude argument.
    
    Returns:
    
    v + ω true latitude argument (rad)
  - getAlphaVDot
```
public double getAlphaVDot()
```
    Get the true latitude argument derivative.
    If the orbit was created without derivatives, the value returned is Double.NaN.
    
    Returns:
    
    v + ω true latitude argument derivative (rad/s)
    
    Since:
    
    9.0
  - getAlphaE
```
public double getAlphaE()
```
    Get the eccentric latitude argument.
    
    Returns:
    
    E + ω eccentric latitude argument (rad)
  - getAlphaEDot
```
public double getAlphaEDot()
```
    Get the eccentric latitude argument derivative.
    If the orbit was created without derivatives, the value returned is Double.NaN.
    
    Returns:
    
    d(E + ω)/dt eccentric latitude argument derivative (rad/s)
    
    Since:
    
    9.0
  - getAlphaM
```
public double getAlphaM()
```
    Get the mean latitude argument.
    
    Returns:
    
    M + ω mean latitude argument (rad)
  - getAlphaMDot
```
public double getAlphaMDot()
```
    Get the mean latitude argument derivative.
    If the orbit was created without derivatives, the value returned is Double.NaN.
    
    Returns:
    
    d(M + ω)/dt mean latitude argument derivative (rad/s)
    
    Since:
    
    9.0
  - getAlpha
```
public double getAlpha(PositionAngleType type)
```
    Get the latitude argument.
    
    Parameters:
    
    type - type of the angle
    
    Returns:
    
    latitude argument (rad)
  - getAlphaDot
```
public double getAlphaDot(PositionAngleType type)
```
    Get the latitude argument derivative.
    If the orbit was created without derivatives, the value returned is Double.NaN.
    
    Parameters:
    
    type - type of the angle
    
    Returns:
    
    latitude argument derivative (rad/s)
    
    Since:
    
    9.0
  - getE
```
public double getE()
```
    Get the eccentricity.
    
    Specified by:
    
    getE in class Orbit
    
    Returns:
    
    eccentricity
  - 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 class Orbit
    
    Returns:
    
    eccentricity derivative
    
    See Also:
    
    Orbit.hasDerivatives()
  - getI
```
public double getI()
```
    Get the inclination.
    
    Specified by:
    
    getI in class Orbit
    
    Returns:
    
    inclination (rad)
  - 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 class Orbit
    
    Returns:
    
    inclination derivative (rad/s)
    
    See Also:
    
    Orbit.hasDerivatives()
  - getRightAscensionOfAscendingNode
```
public double getRightAscensionOfAscendingNode()
```
    Get the right ascension of the ascending node.
    
    Returns:
    
    right ascension of the ascending node (rad)
  - 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
  - getLv
```
public double getLv()
```
    Get the true longitude argument.
    
    Specified by:
    
    getLv in class Orbit
    
    Returns:
    
    v + ω + Ω true longitude argument (rad)
  - 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 class Orbit
    
    Returns:
    
    d(v + ω + Ω)/dt true longitude argument derivative (rad/s)
    
    See Also:
    
    Orbit.hasDerivatives()
  - getLE
```
public double getLE()
```
    Get the eccentric longitude argument.
    
    Specified by:
    
    getLE in class Orbit
    
    Returns:
    
    E + ω + Ω eccentric longitude argument (rad)
  - 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 class Orbit
    
    Returns:
    
    d(E + ω + Ω)/dt eccentric longitude argument derivative (rad/s)
    
    See Also:
    
    Orbit.hasDerivatives()
  - getLM
```
public double getLM()
```
    Get the mean longitude argument.
    
    Specified by:
    
    getLM in class Orbit
    
    Returns:
    
    M + ω + Ω mean longitude argument (rad)
  - 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 class Orbit
    
    Returns:
    
    d(M + ω + Ω)/dt mean longitude argument derivative (rad/s)
    
    See Also:
    
    Orbit.hasDerivatives()
  - initPosition
```
protected Vector3D initPosition()
```
    Compute the position coordinates from the canonical parameters.
    
    Specified by:
    
    initPosition in class Orbit
    
    Returns:
    
    computed position coordinates
  - initPVCoordinates
```
protected TimeStampedPVCoordinates initPVCoordinates()
```
    Compute the position/velocity coordinates from the canonical parameters.
    
    Specified by:
    
    initPVCoordinates in class Orbit
    
    Returns:
    
    computed position/velocity coordinates
  - shiftedBy
```
public CircularOrbit 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 interface TimeShiftable<Orbit>
    
    Specified by:
    
    shiftedBy in class Orbit
    
    Parameters:
    
    dt - time shift in seconds
    
    Returns:
    
    a new orbit, shifted with respect to the instance (which is immutable)
  - shiftedBy
```
public CircularOrbit shiftedBy(TimeOffset 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 interface TimeShiftable<Orbit>
    
    Specified by:
    
    shiftedBy in class Orbit
    
    Parameters:
    
    dt - time shift
    
    Returns:
    
    a new orbit, shifted with respect to the instance (which is immutable)
  - 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 class Orbit
    
    Returns:
    
    6x6 Jacobian matrix
    
    See Also:
    
    Orbit.computeJacobianEccentricWrtCartesian(), Orbit.computeJacobianTrueWrtCartesian()
  - 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 class Orbit
    
    Returns:
    
    6x6 Jacobian matrix
    
    See Also:
    
    Orbit.computeJacobianMeanWrtCartesian(), Orbit.computeJacobianTrueWrtCartesian()
  - 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 class Orbit
    
    Returns:
    
    6x6 Jacobian matrix
    
    See Also:
    
    Orbit.computeJacobianMeanWrtCartesian(), Orbit.computeJacobianEccentricWrtCartesian()
  - addKeplerContribution
```
public void addKeplerContribution(PositionAngleType type,
                                  double gm,
                                  double[] 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 Orbit
    
    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 CircularOrbit removeRates()
```
    Create a new instance such that PositionAngleBased.hasRates() is false.
    
    Specified by:
    
    removeRates in interface PositionAngleBased
    
    Returns:
    
    new object without rates

Class CircularOrbit

Constructor Summary

Method Summary

Methods inherited from class org.orekit.orbits.Orbit

Methods inherited from class java.lang.Object

Methods inherited from interface org.orekit.time.TimeStamped

Constructor Detail

CircularOrbit

CircularOrbit

CircularOrbit

CircularOrbit

CircularOrbit

CircularOrbit

CircularOrbit

Method Detail

getType

getA

getADot

getEquinoctialEx

getEquinoctialExDot

getEquinoctialEy

getEquinoctialEyDot

getCircularEx

getCircularExDot

getCircularEy

getCircularEyDot

getHx

getHxDot

getHy

getHyDot

getAlphaV

getAlphaVDot

getAlphaE

getAlphaEDot

getAlphaM

getAlphaMDot

getAlpha

getAlphaDot

getE

getEDot

getI

getIDot

getRightAscensionOfAscendingNode

getRightAscensionOfAscendingNodeDot

getLv

getLvDot

getLE

getLEDot

getLM

getLMDot

initPosition

initPVCoordinates

shiftedBy

shiftedBy

computeJacobianMeanWrtCartesian

computeJacobianEccentricWrtCartesian

computeJacobianTrueWrtCartesian

addKeplerContribution

toString

getCachedPositionAngleType

hasRates

removeRates