Package org.orekit.orbits

Class FieldCircularOrbit<T extends CalculusFieldElement<T>>

  • Type Parameters:
    T - type of the field elements
    All Implemented Interfaces:
    PositionAngleBased<FieldCircularOrbit<T>>, FieldTimeShiftable<FieldOrbit<T>,​T>, FieldTimeStamped<T>, TimeShiftable<FieldOrbit<T>>, FieldPVCoordinatesProvider<T>
    public class FieldCircularOrbit<T extends CalculusFieldElement<T>>
extends FieldOrbit<T>
implements PositionAngleBased<FieldCircularOrbit<T>>
    This class handles circular orbital parameters.

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

    • a
    • ex = e cos(ω)
    • ey = e sin(ω)
    • i
    • Ω
    • αv = v + ω
    where Ω stands for the Right Ascension of the Ascending Node and αv 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 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​(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

      • 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)

      • 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)

      • 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)

      • 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)

      • 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)

      • withFrame

        public FieldCircularOrbit<T> withFrame​(Frame inertialFrame)
        Create a new object representing the same physical orbital state, but attached to a different reference frame. If the new frame is not inertial, an exception will be thrown.
        Specified by:
        withFrame in class FieldOrbit<T extends CalculusFieldElement<T>>
        Parameters:
        inertialFrame - reference frame of output orbit
        Returns:
        orbit with different frame

      • 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

      • 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