java.lang.Object
- org.orekit.propagation.FieldAbstractPropagator<T>
- - org.orekit.propagation.analytical.FieldAbstractAnalyticalPropagator<T>
  - - org.orekit.propagation.analytical.FieldBrouwerLyddanePropagator<T>

Type Parameters:

T - type of the field elements

All Implemented Interfaces:

FieldPropagator<T>, FieldPVCoordinatesProvider<T>, ParameterDriversProvider
```
public class FieldBrouwerLyddanePropagator<T extends CalculusFieldElement<T>>
extends FieldAbstractAnalyticalPropagator<T>
```
This class propagates a FieldSpacecraftState using the analytical Brouwer-Lyddane model (from J2 to J5 zonal harmonics).
At the opposite of the FieldEcksteinHechlerPropagator, the Brouwer-Lyddane model is suited for elliptical orbits, there is no problem having a rather small eccentricity or inclination (Lyddane helped to solve this issue with the Brouwer model). Singularity for the critical inclination i = 63.4° is avoided using the method developed in Warren Phipps' 1992 thesis.
By default, Brouwer-Lyddane model considers only the perturbations due to zonal harmonics. However, for low Earth orbits, the magnitude of the perturbative acceleration due to atmospheric drag can be significant. Warren Phipps' 1992 thesis considered the atmospheric drag by time derivatives of the mean mean anomaly using the catch-all coefficient M2Driver. Usually, M2 is adjusted during an orbit determination process and it represents the combination of all unmodeled secular along-track effects (i.e. not just the atmospheric drag). The behavior of M2 is close to the FieldTLE.getBStar() parameter for the TLE. If the value of M2 is equal to 0.0, the along-track secular effects are not considered in the dynamical model. Typical values for M2 are not known. It depends on the orbit type. However, the value of M2 must be very small (e.g. between 1.0e-14 and 1.0e-15). The unit of M2 is rad/s². The along-track effects, represented by the secular rates of the mean semi-major axis and eccentricity, are computed following Eq. 2.38, 2.41, and 2.45 of Warren Phipps' thesis.

Since:

11.1

Author:

Melina Vanel, Bryan Cazabonne

See Also:

"Brouwer, Dirk. Solution of the problem of artificial satellite theory without drag. YALE UNIV NEW HAVEN CT NEW HAVEN United States, 1959.", "Lyddane, R. H. Small eccentricities or inclinations in the Brouwer theory of the artificial satellite. The Astronomical Journal 68 (1963): 555.", "Phipps Jr, Warren E. Parallelization of the Navy Space Surveillance Center (NAVSPASUR) Satellite Model. NAVAL POSTGRADUATE SCHOOL MONTEREY CA, 1992."

Field Summary
- Fields inherited from interface org.orekit.propagation.FieldPropagator
  DEFAULT_MASS

Constructor Summary

Constructors
Constructor	Description
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, double referenceRadius, T mu, double c20, double c30, double c40, double c50, double M2)`	Build a propagator from orbit and potential.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitudeProv, double referenceRadius, T mu, double c20, double c30, double c40, double c50, double M2)`	Build a propagator from orbit, attitude provider and potential.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitudeProv, UnnormalizedSphericalHarmonicsProvider provider, double M2)`	Build a propagator from orbit, attitude provider and potential provider.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitudeProv, T mass, double referenceRadius, T mu, double c20, double c30, double c40, double c50, double M2)`	Build a propagator from orbit, attitude provider, mass and potential.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitudeProv, T mass, double referenceRadius, T mu, double c20, double c30, double c40, double c50, PropagationType initialType, double M2)`	Build a propagator from orbit, attitude provider, mass and potential.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitudeProv, T mass, double referenceRadius, T mu, double c20, double c30, double c40, double c50, PropagationType initialType, double M2, double epsilon, int maxIterations)`	Build a propagator from orbit, attitude provider, mass and potential.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitudeProv, T mass, UnnormalizedSphericalHarmonicsProvider provider, double M2)`	Build a propagator from orbit, attitude provider, mass and potential provider.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitude, T mass, UnnormalizedSphericalHarmonicsProvider provider, UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics, double M2)`	Private helper constructor.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitude, T mass, UnnormalizedSphericalHarmonicsProvider provider, UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics, PropagationType initialType, double M2)`	Private helper constructor.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, AttitudeProvider attitudeProv, T mass, UnnormalizedSphericalHarmonicsProvider provider, PropagationType initialType, double M2)`	Build a propagator from orbit, attitude provider, mass and potential provider.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, UnnormalizedSphericalHarmonicsProvider provider, double M2)`	Build a propagator from orbit and potential provider.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, UnnormalizedSphericalHarmonicsProvider provider, PropagationType initialType, double M2)`	Build a propagator from orbit and potential provider.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, T mass, double referenceRadius, T mu, double c20, double c30, double c40, double c50, double M2)`	Build a propagator from orbit, mass and potential.
`FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit, T mass, UnnormalizedSphericalHarmonicsProvider provider, double M2)`	Build a propagator from orbit, mass and potential provider.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static <T extends CalculusFieldElement<T>> FieldKeplerianOrbit<T>`	`computeMeanOrbit(FieldOrbit<T> osculating, double referenceRadius, double mu, double c20, double c30, double c40, double c50, double M2Value, double epsilon, int maxIterations)`	Conversion from osculating to mean orbit.
`static <T extends CalculusFieldElement<T>> FieldKeplerianOrbit<T>`	`computeMeanOrbit(FieldOrbit<T> osculating, UnnormalizedSphericalHarmonicsProvider provider, UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics, double M2Value)`	Conversion from osculating to mean orbit.
`static <T extends CalculusFieldElement<T>> FieldKeplerianOrbit<T>`	`computeMeanOrbit(FieldOrbit<T> osculating, UnnormalizedSphericalHarmonicsProvider provider, UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics, double M2Value, double epsilon, int maxIterations)`	Conversion from osculating to mean orbit.
`double`	`getM2()`	Get the value of the M2 drag parameter.
`double`	`getM2(AbsoluteDate date)`	Get the value of the M2 drag parameter.
`protected T`	`getMass(FieldAbsoluteDate<T> date)`	Get the mass.
`List<ParameterDriver>`	`getParametersDrivers()`	Get the drivers for parameters.
`FieldKeplerianOrbit<T>`	`propagateOrbit(FieldAbsoluteDate<T> date, T[] parameters)`	Extrapolate an orbit up to a specific target date.
`void`	`resetInitialState(FieldSpacecraftState<T> state)`	Reset the propagator initial state.
`void`	`resetInitialState(FieldSpacecraftState<T> state, PropagationType stateType)`	Reset the propagator initial state.
`void`	`resetInitialState(FieldSpacecraftState<T> state, PropagationType stateType, double epsilon, int maxIterations)`	Reset the propagator initial state.
`protected void`	`resetIntermediateState(FieldSpacecraftState<T> state, boolean forward)`	Reset an intermediate state.
`protected void`	`resetIntermediateState(FieldSpacecraftState<T> state, boolean forward, double epsilon, int maxIterations)`	Reset an intermediate state.

Methods inherited from class org.orekit.propagation.analytical.FieldAbstractAnalyticalPropagator
acceptStep, addEventDetector, basicPropagate, clearEventsDetectors, getEphemerisGenerator, getEventsDetectors, getPvProvider, propagate

Methods inherited from class org.orekit.propagation.FieldAbstractPropagator
addAdditionalStateProvider, getAdditionalStateProviders, getAttitudeProvider, getField, getFrame, getInitialState, getManagedAdditionalStates, getMultiplexer, getPVCoordinates, getStartDate, initializeAdditionalStates, initializePropagation, isAdditionalStateManaged, propagate, setAttitudeProvider, setStartDate, stateChanged, updateAdditionalStates, updateUnmanagedStates

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

Methods inherited from interface org.orekit.propagation.FieldPropagator
clearStepHandlers, setStepHandler, setStepHandler

Methods inherited from interface org.orekit.utils.FieldPVCoordinatesProvider
getPosition

Methods inherited from interface org.orekit.utils.ParameterDriversProvider
getNbParametersDriversValue, getParameterDriver, getParameters, getParameters, getParameters, getParameters, getParametersAllValues, getParametersAllValues, isSupported

- Constructor Detail
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     double M2)
```
    Build a propagator from orbit and potential provider.
    Mass and attitude provider are set to unspecified non-null arbitrary values.
    
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    provider - for un-normalized zonal coefficients
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    See Also:
    
    FieldBrouwerLyddanePropagator(FieldOrbit, UnnormalizedSphericalHarmonicsProvider, PropagationType, double)
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitude,
                                     T mass,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics,
                                     double M2)
```
    Private helper constructor.
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitude - attitude provider
    
    mass - spacecraft mass
    
    provider - for un-normalized zonal coefficients
    
    harmonics - provider.onDate(initialOrbit.getDate())
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    See Also:
    
    FieldBrouwerLyddanePropagator(FieldOrbit, AttitudeProvider, CalculusFieldElement, UnnormalizedSphericalHarmonicsProvider, UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics, PropagationType, double)
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     double referenceRadius,
                                     T mu,
                                     double c20,
                                     double c30,
                                     double c40,
                                     double c50,
                                     double M2)
```
    Build a propagator from orbit and potential.
    Mass and attitude provider are set to unspecified non-null arbitrary values.
    
    The C_n,0 coefficients are the denormalized zonal coefficients, they are related to both the normalized coefficients C_n,0 and the J_n one as follows:
    
    C_n,0 = [(2-δ_0,m)(2n+1)(n-m)!/(n+m)!]^½ C_n,0
    C_n,0 = -J_n
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    referenceRadius - reference radius of the Earth for the potential model (m)
    
    mu - central attraction coefficient (m³/s²)
    
    c20 - un-normalized zonal coefficient (about -1.08e-3 for Earth)
    
    c30 - un-normalized zonal coefficient (about +2.53e-6 for Earth)
    
    c40 - un-normalized zonal coefficient (about +1.62e-6 for Earth)
    
    c50 - un-normalized zonal coefficient (about +2.28e-7 for Earth)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    See Also:
    
    Constants, FieldBrouwerLyddanePropagator(FieldOrbit, AttitudeProvider, double, CalculusFieldElement, double, double, double, double, double)
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     T mass,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     double M2)
```
    Build a propagator from orbit, mass and potential provider.
    Attitude law is set to an unspecified non-null arbitrary value.
    
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    mass - spacecraft mass
    
    provider - for un-normalized zonal coefficients
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    See Also:
    
    FieldBrouwerLyddanePropagator(FieldOrbit, AttitudeProvider, CalculusFieldElement, UnnormalizedSphericalHarmonicsProvider, double)
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     T mass,
                                     double referenceRadius,
                                     T mu,
                                     double c20,
                                     double c30,
                                     double c40,
                                     double c50,
                                     double M2)
```
    Build a propagator from orbit, mass and potential.
    Attitude law is set to an unspecified non-null arbitrary value.
    
    The C_n,0 coefficients are the denormalized zonal coefficients, they are related to both the normalized coefficients C_n,0 and the J_n one as follows:
    
    C_n,0 = [(2-δ_0,m)(2n+1)(n-m)!/(n+m)!]^½ C_n,0
    C_n,0 = -J_n
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    mass - spacecraft mass
    
    referenceRadius - reference radius of the Earth for the potential model (m)
    
    mu - central attraction coefficient (m³/s²)
    
    c20 - un-normalized zonal coefficient (about -1.08e-3 for Earth)
    
    c30 - un-normalized zonal coefficient (about +2.53e-6 for Earth)
    
    c40 - un-normalized zonal coefficient (about +1.62e-6 for Earth)
    
    c50 - un-normalized zonal coefficient (about +2.28e-7 for Earth)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    See Also:
    
    FieldBrouwerLyddanePropagator(FieldOrbit, AttitudeProvider, CalculusFieldElement, double, CalculusFieldElement, double, double, double, double, double)
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitudeProv,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     double M2)
```
    Build a propagator from orbit, attitude provider and potential provider.
    Mass is set to an unspecified non-null arbitrary value.
    
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitudeProv - attitude provider
    
    provider - for un-normalized zonal coefficients
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitudeProv,
                                     double referenceRadius,
                                     T mu,
                                     double c20,
                                     double c30,
                                     double c40,
                                     double c50,
                                     double M2)
```
    Build a propagator from orbit, attitude provider and potential.
    Mass is set to an unspecified non-null arbitrary value.
    
    The C_n,0 coefficients are the denormalized zonal coefficients, they are related to both the normalized coefficients C_n,0 and the J_n one as follows:
    
    C_n,0 = [(2-δ_0,m)(2n+1)(n-m)!/(n+m)!]^½ C_n,0
    C_n,0 = -J_n
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitudeProv - attitude provider
    
    referenceRadius - reference radius of the Earth for the potential model (m)
    
    mu - central attraction coefficient (m³/s²)
    
    c20 - un-normalized zonal coefficient (about -1.08e-3 for Earth)
    
    c30 - un-normalized zonal coefficient (about +2.53e-6 for Earth)
    
    c40 - un-normalized zonal coefficient (about +1.62e-6 for Earth)
    
    c50 - un-normalized zonal coefficient (about +2.28e-7 for Earth)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitudeProv,
                                     T mass,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     double M2)
```
    Build a propagator from orbit, attitude provider, mass and potential provider.
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitudeProv - attitude provider
    
    mass - spacecraft mass
    
    provider - for un-normalized zonal coefficients
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    See Also:
    
    FieldBrouwerLyddanePropagator(FieldOrbit, AttitudeProvider, CalculusFieldElement, UnnormalizedSphericalHarmonicsProvider, PropagationType, double)
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitudeProv,
                                     T mass,
                                     double referenceRadius,
                                     T mu,
                                     double c20,
                                     double c30,
                                     double c40,
                                     double c50,
                                     double M2)
```
    Build a propagator from orbit, attitude provider, mass and potential.
    The C_n,0 coefficients are the denormalized zonal coefficients, they are related to both the normalized coefficients C_n,0 and the J_n one as follows:
    
    C_n,0 = [(2-δ_0,m)(2n+1)(n-m)!/(n+m)!]^½ C_n,0
    C_n,0 = -J_n
    Using this constructor, an initial osculating orbit is considered.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitudeProv - attitude provider
    
    mass - spacecraft mass
    
    referenceRadius - reference radius of the Earth for the potential model (m)
    
    mu - central attraction coefficient (m³/s²)
    
    c20 - un-normalized zonal coefficient (about -1.08e-3 for Earth)
    
    c30 - un-normalized zonal coefficient (about +2.53e-6 for Earth)
    
    c40 - un-normalized zonal coefficient (about +1.62e-6 for Earth)
    
    c50 - un-normalized zonal coefficient (about +2.28e-7 for Earth)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    See Also:
    
    FieldBrouwerLyddanePropagator(FieldOrbit, AttitudeProvider, CalculusFieldElement, double, CalculusFieldElement, double, double, double, double, PropagationType, double)
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     PropagationType initialType,
                                     double M2)
```
    Build a propagator from orbit and potential provider.
    Mass and attitude provider are set to unspecified non-null arbitrary values.
    
    Using this constructor, it is possible to define the initial orbit as a mean Brouwer-Lyddane orbit or an osculating one.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    provider - for un-normalized zonal coefficients
    
    initialType - initial orbit type (mean Brouwer-Lyddane orbit or osculating orbit)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitudeProv,
                                     T mass,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     PropagationType initialType,
                                     double M2)
```
    Build a propagator from orbit, attitude provider, mass and potential provider.
    Using this constructor, it is possible to define the initial orbit as a mean Brouwer-Lyddane orbit or an osculating one.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitudeProv - attitude provider
    
    mass - spacecraft mass
    
    provider - for un-normalized zonal coefficients
    
    initialType - initial orbit type (mean Brouwer-Lyddane orbit or osculating orbit)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitude,
                                     T mass,
                                     UnnormalizedSphericalHarmonicsProvider provider,
                                     UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics,
                                     PropagationType initialType,
                                     double M2)
```
    Private helper constructor.
    Using this constructor, it is possible to define the initial orbit as a mean Brouwer-Lyddane orbit or an osculating one.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitude - attitude provider
    
    mass - spacecraft mass
    
    provider - for un-normalized zonal coefficients
    
    harmonics - provider.onDate(initialOrbit.getDate())
    
    initialType - initial orbit type (mean Brouwer-Lyddane orbit or osculating orbit)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitudeProv,
                                     T mass,
                                     double referenceRadius,
                                     T mu,
                                     double c20,
                                     double c30,
                                     double c40,
                                     double c50,
                                     PropagationType initialType,
                                     double M2)
```
    Build a propagator from orbit, attitude provider, mass and potential.
    The C_n,0 coefficients are the denormalized zonal coefficients, they are related to both the normalized coefficients C_n,0 and the J_n one as follows:
    
    C_n,0 = [(2-δ_0,m)(2n+1)(n-m)!/(n+m)!]^½ C_n,0
    C_n,0 = -J_n
    Using this constructor, it is possible to define the initial orbit as a mean Brouwer-Lyddane orbit or an osculating one.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitudeProv - attitude provider
    
    mass - spacecraft mass
    
    referenceRadius - reference radius of the Earth for the potential model (m)
    
    mu - central attraction coefficient (m³/s²)
    
    c20 - un-normalized zonal coefficient (about -1.08e-3 for Earth)
    
    c30 - un-normalized zonal coefficient (about +2.53e-6 for Earth)
    
    c40 - un-normalized zonal coefficient (about +1.62e-6 for Earth)
    
    c50 - un-normalized zonal coefficient (about +2.28e-7 for Earth)
    
    initialType - initial orbit type (mean Brouwer-Lyddane orbit or osculating orbit)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
  - FieldBrouwerLyddanePropagator
```
public FieldBrouwerLyddanePropagator(FieldOrbit<T> initialOrbit,
                                     AttitudeProvider attitudeProv,
                                     T mass,
                                     double referenceRadius,
                                     T mu,
                                     double c20,
                                     double c30,
                                     double c40,
                                     double c50,
                                     PropagationType initialType,
                                     double M2,
                                     double epsilon,
                                     int maxIterations)
```
    Build a propagator from orbit, attitude provider, mass and potential.
    The C_n,0 coefficients are the denormalized zonal coefficients, they are related to both the normalized coefficients C_n,0 and the J_n one as follows:
    
    C_n,0 = [(2-δ_0,m)(2n+1)(n-m)!/(n+m)!]^½ C_n,0
    C_n,0 = -J_n
    Using this constructor, it is possible to define the initial orbit as a mean Brouwer-Lyddane orbit or an osculating one.
    
    Parameters:
    
    initialOrbit - initial orbit
    
    attitudeProv - attitude provider
    
    mass - spacecraft mass
    
    referenceRadius - reference radius of the Earth for the potential model (m)
    
    mu - central attraction coefficient (m³/s²)
    
    c20 - un-normalized zonal coefficient (about -1.08e-3 for Earth)
    
    c30 - un-normalized zonal coefficient (about +2.53e-6 for Earth)
    
    c40 - un-normalized zonal coefficient (about +1.62e-6 for Earth)
    
    c50 - un-normalized zonal coefficient (about +2.28e-7 for Earth)
    
    initialType - initial orbit type (mean Brouwer-Lyddane orbit or osculating orbit)
    
    M2 - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not computed
    
    epsilon - convergence threshold for mean parameters conversion
    
    maxIterations - maximum iterations for mean parameters conversion
    
    Since:
    
    11.2
- Method Detail
  - computeMeanOrbit
```
public static <T extends CalculusFieldElement<T>> FieldKeplerianOrbit<T> computeMeanOrbit(FieldOrbit<T> osculating,
                                                                                          UnnormalizedSphericalHarmonicsProvider provider,
                                                                                          UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics,
                                                                                          double M2Value)
```
    Conversion from osculating to mean orbit.
    Compute mean orbit in a Brouwer-Lyddane sense, corresponding to the osculating SpacecraftState in input.
    
    Since the osculating orbit is obtained with the computation of short-periodic variation, the resulting output will depend on both the gravity field parameterized in input and the atmospheric drag represented by the m2 parameter.
    
    The computation is done through a fixed-point iteration process.
    
    Type Parameters:
    
    T - type of the filed elements
    
    Parameters:
    
    osculating - osculating orbit to convert
    
    provider - for un-normalized zonal coefficients
    
    harmonics - provider.onDate(osculating.getDate())
    
    M2Value - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not considered
    
    Returns:
    
    mean orbit in a Brouwer-Lyddane sense
    
    Since:
    
    11.2
  - computeMeanOrbit
```
public static <T extends CalculusFieldElement<T>> FieldKeplerianOrbit<T> computeMeanOrbit(FieldOrbit<T> osculating,
                                                                                          UnnormalizedSphericalHarmonicsProvider provider,
                                                                                          UnnormalizedSphericalHarmonicsProvider.UnnormalizedSphericalHarmonics harmonics,
                                                                                          double M2Value,
                                                                                          double epsilon,
                                                                                          int maxIterations)
```
    Conversion from osculating to mean orbit.
    Compute mean orbit in a Brouwer-Lyddane sense, corresponding to the osculating SpacecraftState in input.
    
    Since the osculating orbit is obtained with the computation of short-periodic variation, the resulting output will depend on both the gravity field parameterized in input and the atmospheric drag represented by the m2 parameter.
    
    The computation is done through a fixed-point iteration process.
    
    Type Parameters:
    
    T - type of the filed elements
    
    Parameters:
    
    osculating - osculating orbit to convert
    
    provider - for un-normalized zonal coefficients
    
    harmonics - provider.onDate(osculating.getDate())
    
    M2Value - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not considered
    
    epsilon - convergence threshold for mean parameters conversion
    
    maxIterations - maximum iterations for mean parameters conversion
    
    Returns:
    
    mean orbit in a Brouwer-Lyddane sense
    
    Since:
    
    11.2
  - computeMeanOrbit
```
public static <T extends CalculusFieldElement<T>> FieldKeplerianOrbit<T> computeMeanOrbit(FieldOrbit<T> osculating,
                                                                                          double referenceRadius,
                                                                                          double mu,
                                                                                          double c20,
                                                                                          double c30,
                                                                                          double c40,
                                                                                          double c50,
                                                                                          double M2Value,
                                                                                          double epsilon,
                                                                                          int maxIterations)
```
    Conversion from osculating to mean orbit.
    Compute mean orbit in a Brouwer-Lyddane sense, corresponding to the osculating SpacecraftState in input.
    
    Since the osculating orbit is obtained with the computation of short-periodic variation, the resulting output will depend on both the gravity field parameterized in input and the atmospheric drag represented by the m2 parameter.
    
    The computation is done through a fixed-point iteration process.
    
    Type Parameters:
    
    T - type of the filed elements
    
    Parameters:
    
    osculating - osculating orbit to convert
    
    referenceRadius - reference radius of the Earth for the potential model (m)
    
    mu - central attraction coefficient (m³/s²)
    
    c20 - un-normalized zonal coefficient (about -1.08e-3 for Earth)
    
    c30 - un-normalized zonal coefficient (about +2.53e-6 for Earth)
    
    c40 - un-normalized zonal coefficient (about +1.62e-6 for Earth)
    
    c50 - un-normalized zonal coefficient (about +2.28e-7 for Earth)
    
    M2Value - value of empirical drag coefficient in rad/s². If equal to BrouwerLyddanePropagator.M2 drag is not considered
    
    epsilon - convergence threshold for mean parameters conversion
    
    maxIterations - maximum iterations for mean parameters conversion
    
    Returns:
    
    mean orbit in a Brouwer-Lyddane sense
    
    Since:
    
    11.2
  - resetInitialState
```
public void resetInitialState(FieldSpacecraftState<T> state)
```
    Reset the propagator initial state.
    The new initial state to consider must be defined with an osculating orbit.
    
    Specified by:
    
    resetInitialState in interface FieldPropagator<T extends CalculusFieldElement<T>>
    
    Overrides:
    
    resetInitialState in class FieldAbstractPropagator<T extends CalculusFieldElement<T>>
    
    Parameters:
    
    state - new initial state to consider
    
    See Also:
    
    resetInitialState(FieldSpacecraftState, PropagationType)
  - resetInitialState
```
public void resetInitialState(FieldSpacecraftState<T> state,
                              PropagationType stateType)
```
    Reset the propagator initial state.
    
    Parameters:
    
    state - new initial state to consider
    
    stateType - mean Brouwer-Lyddane orbit or osculating orbit
  - resetInitialState
```
public void resetInitialState(FieldSpacecraftState<T> state,
                              PropagationType stateType,
                              double epsilon,
                              int maxIterations)
```
    Reset the propagator initial state.
    
    Parameters:
    
    state - new initial state to consider
    
    stateType - mean Brouwer-Lyddane orbit or osculating orbit
    
    epsilon - convergence threshold for mean parameters conversion
    
    maxIterations - maximum iterations for mean parameters conversion
    
    Since:
    
    11.2
  - resetIntermediateState
```
protected void resetIntermediateState(FieldSpacecraftState<T> state,
                                      boolean forward)
```
    Reset an intermediate state.
    
    Specified by:
    
    resetIntermediateState in class FieldAbstractAnalyticalPropagator<T extends CalculusFieldElement<T>>
    
    Parameters:
    
    state - new intermediate state to consider
    
    forward - if true, the intermediate state is valid for propagations after itself
  - resetIntermediateState
```
protected void resetIntermediateState(FieldSpacecraftState<T> state,
                                      boolean forward,
                                      double epsilon,
                                      int maxIterations)
```
    Reset an intermediate state.
    
    Parameters:
    
    state - new intermediate state to consider
    
    forward - if true, the intermediate state is valid for propagations after itself
    
    epsilon - convergence threshold for mean parameters conversion
    
    maxIterations - maximum iterations for mean parameters conversion
    
    Since:
    
    11.2
  - propagateOrbit
```
public FieldKeplerianOrbit<T> propagateOrbit(FieldAbsoluteDate<T> date,
                                             T[] parameters)
```
    Extrapolate an orbit up to a specific target date.
    
    Specified by:
    
    propagateOrbit in class FieldAbstractAnalyticalPropagator<T extends CalculusFieldElement<T>>
    
    Parameters:
    
    date - target date for the orbit
    
    parameters - model parameters
    
    Returns:
    
    extrapolated parameters
  - getM2
```
public double getM2()
```
    Get the value of the M2 drag parameter.
    
    Returns:
    
    the value of the M2 drag parameter
  - getM2
```
public double getM2(AbsoluteDate date)
```
    Get the value of the M2 drag parameter.
    
    Parameters:
    
    date - date at which the model parameters want to be known
    
    Returns:
    
    the value of the M2 drag parameter
  - getMass
```
protected T getMass(FieldAbsoluteDate<T> date)
```
    Get the mass.
    
    Specified by:
    
    getMass in class FieldAbstractAnalyticalPropagator<T extends CalculusFieldElement<T>>
    
    Parameters:
    
    date - target date for the orbit
    
    Returns:
    
    mass mass
  - getParametersDrivers
```
public List<ParameterDriver> getParametersDrivers()
```
    Get the drivers for parameters.
    
    Returns:
    
    drivers for parameters

Class FieldBrouwerLyddanePropagator<T extends CalculusFieldElement<T>>

Field Summary

Fields inherited from interface org.orekit.propagation.FieldPropagator

Constructor Summary

Method Summary

Methods inherited from class org.orekit.propagation.analytical.FieldAbstractAnalyticalPropagator

Methods inherited from class org.orekit.propagation.FieldAbstractPropagator

Methods inherited from class java.lang.Object

Methods inherited from interface org.orekit.propagation.FieldPropagator

Methods inherited from interface org.orekit.utils.FieldPVCoordinatesProvider

Methods inherited from interface org.orekit.utils.ParameterDriversProvider

Constructor Detail

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

FieldBrouwerLyddanePropagator

Method Detail

computeMeanOrbit

computeMeanOrbit

computeMeanOrbit

resetInitialState

resetInitialState

resetInitialState

resetIntermediateState

resetIntermediateState

propagateOrbit

getM2

getM2

getMass

getParametersDrivers