Package org.orekit.orbits

Class FieldKeplerianOrbit<T extends CalculusFieldElement<T>>

java.lang.Object
org.orekit.orbits.FieldOrbit<T>
org.orekit.orbits.FieldKeplerianOrbit<T>
Type Parameters:
T - type of the field elements
All Implemented Interfaces:
PositionAngleBased<FieldKeplerianOrbit<T>>, FieldTimeShiftable<ShiftableFieldPVCoordinatesHolder<FieldOrbit<T>,T>,T>, FieldTimeStamped<T>, TimeShiftable<ShiftableFieldPVCoordinatesHolder<FieldOrbit<T>,T>>, FieldPVCoordinatesProvider<T>, ShiftableFieldPVCoordinatesHolder<FieldOrbit<T>,T>
public class FieldKeplerianOrbit<T extends CalculusFieldElement<T>> extends FieldOrbit<T> implements PositionAngleBased<FieldKeplerianOrbit<T>>
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.

Since:
9.0
Author:
Luc Maisonobe, Guylaine Prat, Fabien Maussion, Véronique Pommier-Maurussane, Andrea Antolino
See Also:

  • Constructor Details

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(FieldKeplerianParameters<T> elements, Frame frame, FieldAbsoluteDate<T> date, T mu) throws IllegalArgumentException
      Creates a new instance.
      Parameters:
      elements - Keplerian elements
      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 frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits
      Since:
      14.0

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(T a, T e, T i, T pa, T raan, T anomaly, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu) throws IllegalArgumentException
      Creates a new instance.
      Parameters:
      a - semi-major axis (m), negative for hyperbolic orbits
      e - 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 anomaly
      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 frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits
      Since:
      12.1

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(FieldKeplerianParameters<T> elements, T aDot, T eDot, T iDot, T paDot, T raanDot, T anomalyDot, PositionAngleType cachedPositionAngleType, Frame frame, FieldAbsoluteDate<T> date, T mu) throws IllegalArgumentException
      Creates a new instance.
      Parameters:
      elements - Keplerian elements
      aDot - semi-major axis derivative, null if unknown (m/s)
      eDot - eccentricity derivative, null if unknown
      iDot - inclination derivative, null if unknown (rad/s)
      paDot - perigee argument derivative, null if unknown (rad/s)
      raanDot - right ascension of ascending node derivative, null if unknown (rad/s)
      anomalyDot - mean, eccentric or true anomaly derivative, null if unknown (rad/s)
      cachedPositionAngleType - type of cached anomaly
      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 frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits
      Since:
      14.0

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(T a, T e, T i, T pa, T raan, T anomaly, T aDot, T eDot, T iDot, T paDot, T raanDot, T anomalyDot, PositionAngleType type, Frame frame, FieldAbsoluteDate<T> date, T mu) throws IllegalArgumentException
      Creates a new instance.
      Parameters:
      a - semi-major axis (m), negative for hyperbolic orbits
      e - 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, null if unknown (m/s)
      eDot - eccentricity derivative, null if unknown
      iDot - inclination derivative, null if unknown (rad/s)
      paDot - perigee argument derivative, null if unknown (rad/s)
      raanDot - right ascension of ascending node derivative, null if unknown (rad/s)
      anomalyDot - mean, eccentric or true anomaly derivative, null if unknown (rad/s)
      type - type of anomaly
      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 frame is not a pseudo-inertial frame or a and e don't match for hyperbolic orbits, or v is out of range for hyperbolic orbits

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(TimeStampedFieldPVCoordinates<T> pvCoordinates, Frame frame, T mu) throws IllegalArgumentException
      Constructor from Cartesian parameters.

      The acceleration provided in FieldPVCoordinates is accessible using FieldOrbit.getPVCoordinates() and FieldOrbit.getPVCoordinates(Frame). All other methods use mu and the position to compute the acceleration, including shiftedBy(CalculusFieldElement) and FieldOrbit.getPVCoordinates(FieldAbsoluteDate, Frame).

      Parameters:
      pvCoordinates - the PVCoordinates of the satellite
      frame - the frame in which are defined the FieldPVCoordinates (must be a pseudo-inertial frame)
      mu - central attraction coefficient (m³/s²)
      Throws:
      IllegalArgumentException - if frame is not a pseudo-inertial frame

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(FieldPVCoordinates<T> FieldPVCoordinates, Frame frame, FieldAbsoluteDate<T> date, T mu) throws IllegalArgumentException
      Constructor from Cartesian parameters.

      The acceleration provided in FieldPVCoordinates is accessible using FieldOrbit.getPVCoordinates() and FieldOrbit.getPVCoordinates(Frame). All other methods use mu and the position to compute the acceleration, including shiftedBy(CalculusFieldElement) and FieldOrbit.getPVCoordinates(FieldAbsoluteDate, Frame).

      Parameters:
      FieldPVCoordinates - the PVCoordinates of the satellite
      frame - the frame in which are defined the FieldPVCoordinates (must be a pseudo-inertial frame)
      date - date of the orbital parameters
      mu - central attraction coefficient (m³/s²)
      Throws:
      IllegalArgumentException - if frame is not a pseudo-inertial frame

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(FieldOrbit<T> op)
      Constructor from any kind of orbital parameters.
      Parameters:
      op - orbital parameters to copy

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(Field<T> field, KeplerianOrbit op)
      Constructor from Field and KeplerianOrbit.

      Build a FieldKeplerianOrbit from non-Field KeplerianOrbit.

      Parameters:
      field - CalculusField to base object on
      op - non-field orbit with only "constant" terms
      Since:
      12.0

    • FieldKeplerianOrbit

      public FieldKeplerianOrbit(Field<T> field, Orbit op)
      Constructor from Field and Orbit.

      Build a FieldKeplerianOrbit from any non-Field Orbit.

      Parameters:
      field - CalculusField to base object on
      op - non-field orbit with only "constant" terms
      Since:
      12.0

  • Method Details

    • 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)

    • 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)

    • getPerigeeArgument

      public T getPerigeeArgument()
      Get the perigee argument.
      Returns:
      perigee argument (rad)

    • getPerigeeArgumentDot

      public T getPerigeeArgumentDot()
      Get the perigee argument derivative.
      Returns:
      perigee argument derivative (rad/s)

    • getRightAscensionOfAscendingNode

      public T getRightAscensionOfAscendingNode()
      Get the right ascension of the ascending node.
      Returns:
      right ascension of the ascending node (rad)

    • getRightAscensionOfAscendingNodeDot

      public T getRightAscensionOfAscendingNodeDot()
      Get the right ascension of the ascending node derivative.
      Returns:
      right ascension of the ascending node derivative (rad/s)

    • getTrueAnomaly

      public T getTrueAnomaly()
      Get the true anomaly.
      Returns:
      true anomaly (rad)

    • getTrueAnomalyDot

      public T getTrueAnomalyDot()
      Get the true anomaly derivative.
      Returns:
      true anomaly derivative (rad/s)

    • getEccentricAnomaly

      public T getEccentricAnomaly()
      Get the eccentric anomaly.
      Returns:
      eccentric anomaly (rad)

    • getEccentricAnomalyDot

      public T getEccentricAnomalyDot()
      Get the eccentric anomaly derivative.
      Returns:
      eccentric anomaly derivative (rad/s)

    • getMeanAnomaly

      public T getMeanAnomaly()
      Get the mean anomaly.
      Returns:
      mean anomaly (rad)

    • getMeanAnomalyDot

      public T getMeanAnomalyDot()
      Get the mean anomaly derivative.
      Returns:
      mean anomaly derivative (rad/s)

    • getAnomaly

      public T getAnomaly(PositionAngleType type)
      Get the anomaly.
      Parameters:
      type - type of the angle
      Returns:
      anomaly (rad)

    • getAnomalyDot

      public T getAnomalyDot(PositionAngleType type)
      Get the anomaly derivative.
      Parameters:
      type - type of the angle
      Returns:
      anomaly derivative (rad/s)

    • getKeplerianParameters

      public FieldKeplerianParameters<T> getKeplerianParameters()
      Method providing with the Keplerian elements, using the cached type for the anomaly.
      Returns:
      Keplerian elements
      Since:
      14.0

    • 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:

    • 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)

    • 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 FieldKeplerianOrbit<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 FieldKeplerianOrbit<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 FieldKeplerianOrbit<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 FieldKeplerianOrbit<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)

    • shiftedBy

      public FieldKeplerianOrbit<T> shiftedBy(TimeOffset 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)

    • 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:

    • 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:

    • 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:

    • 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 Keplerian 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 FieldKeplerianOrbit<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 KeplerianOrbit 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