FieldAngularCoordinates (ORbit Extrapolation KIT 9.2 API)

java.lang.Object
- org.orekit.utils.FieldAngularCoordinates<T>

Type Parameters:

T - the type of the field elements

Direct Known Subclasses:

TimeStampedFieldAngularCoordinates
```
public class FieldAngularCoordinates<T extends RealFieldElement<T>>
extends Object
```
Simple container for rotation / rotation rate pairs, using RealFieldElement.
The state can be slightly shifted to close dates. This shift is based on a simple quadratic model. It is not intended as a replacement for proper attitude propagation but should be sufficient for either small time shifts or coarse accuracy.

This class is the angular counterpart to FieldPVCoordinates.

Instances of this class are guaranteed to be immutable.

Since:

6.0

Author:

Luc Maisonobe

See Also:

AngularCoordinates

Constructor Summary

Constructors
Constructor	Description
`FieldAngularCoordinates(Field<T> field, AngularCoordinates ang)`	Builds a FieldAngularCoordinates from a field and a regular AngularCoordinates.
`FieldAngularCoordinates(FieldRotation<FieldDerivativeStructure<T>> r)`	Builds a FieldAngularCoordinates from a `FieldRotation`<`FieldDerivativeStructure`>.
`FieldAngularCoordinates(FieldRotation<T> rotation, FieldVector3D<T> rotationRate)`	Builds a rotation/rotation rate pair.
`FieldAngularCoordinates(FieldRotation<T> rotation, FieldVector3D<T> rotationRate, FieldVector3D<T> rotationAcceleration)`	Builds a rotation / rotation rate / rotation acceleration triplet.
`FieldAngularCoordinates(FieldPVCoordinates<T> u1, FieldPVCoordinates<T> u2, FieldPVCoordinates<T> v1, FieldPVCoordinates<T> v2, double tolerance)`	Build the rotation that transforms a pair of pv coordinates into another one.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`FieldAngularCoordinates<T>`	`addOffset(FieldAngularCoordinates<T> offset)`	Add an offset from the instance.
`FieldPVCoordinates<T>`	`applyTo(FieldPVCoordinates<T> pv)`	Apply the rotation to a pv coordinates.
`FieldPVCoordinates<T>`	`applyTo(PVCoordinates pv)`	Apply the rotation to a pv coordinates.
`TimeStampedFieldPVCoordinates<T>`	`applyTo(TimeStampedFieldPVCoordinates<T> pv)`	Apply the rotation to a pv coordinates.
`TimeStampedFieldPVCoordinates<T>`	`applyTo(TimeStampedPVCoordinates pv)`	Apply the rotation to a pv coordinates.
`static <T extends RealFieldElement<T>> FieldAngularCoordinates<T>`	`createFromModifiedRodrigues(T[][] r)`	Convert a modified Rodrigues vector and derivatives to angular coordinates.
`static <T extends RealFieldElement<T>> FieldVector3D<T>`	`estimateRate(FieldRotation<T> start, FieldRotation<T> end, double dt)`	Estimate rotation rate between two orientations.
`static <T extends RealFieldElement<T>> FieldVector3D<T>`	`estimateRate(FieldRotation<T> start, FieldRotation<T> end, T dt)`	Estimate rotation rate between two orientations.
`static <T extends RealFieldElement<T>> FieldAngularCoordinates<T>`	`getIdentity(Field<T> field)`	Fixed orientation parallel with reference frame (identity rotation, zero rotation rate and acceleration).
`T[][]`	`getModifiedRodrigues(double sign)`	Convert rotation, rate and acceleration to modified Rodrigues vector and derivatives.
`FieldRotation<T>`	`getRotation()`	Get the rotation.
`FieldVector3D<T>`	`getRotationAcceleration()`	Get the rotation acceleration.
`FieldVector3D<T>`	`getRotationRate()`	Get the rotation rate.
`FieldAngularCoordinates<T>`	`revert()`	Revert a rotation / rotation rate / rotation acceleration triplet.
`FieldAngularCoordinates<T>`	`shiftedBy(double dt)`	Get a time-shifted state.
`FieldAngularCoordinates<T>`	`shiftedBy(T dt)`	Get a time-shifted state.
`FieldAngularCoordinates<T>`	`subtractOffset(FieldAngularCoordinates<T> offset)`	Subtract an offset from the instance.
`AngularCoordinates`	`toAngularCoordinates()`	Convert to a regular angular coordinates.
`FieldRotation<FieldDerivativeStructure<T>>`	`toDerivativeStructureRotation(int order)`	Transform the instance to a `FieldRotation`<`FieldDerivativeStructure`>.

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

- Constructor Detail
  - FieldAngularCoordinates
```
public FieldAngularCoordinates(FieldRotation<T> rotation,
                               FieldVector3D<T> rotationRate)
```
    Builds a rotation/rotation rate pair.
    
    Parameters:
    
    rotation - rotation
    
    rotationRate - rotation rate Ω (rad/s)
  - FieldAngularCoordinates
```
public FieldAngularCoordinates(FieldRotation<T> rotation,
                               FieldVector3D<T> rotationRate,
                               FieldVector3D<T> rotationAcceleration)
```
    Builds a rotation / rotation rate / rotation acceleration triplet.
    
    Parameters:
    
    rotation - i.e. the orientation of the vehicle
    
    rotationRate - rotation rate rate Ω, i.e. the spin vector (rad/s)
    
    rotationAcceleration - angular acceleration vector dΩ/dt (rad²/s²)
  - FieldAngularCoordinates
```
public FieldAngularCoordinates(FieldPVCoordinates<T> u1,
                               FieldPVCoordinates<T> u2,
                               FieldPVCoordinates<T> v1,
                               FieldPVCoordinates<T> v2,
                               double tolerance)
                        throws OrekitException
```
    Build the rotation that transforms a pair of pv coordinates into another one.
    WARNING! This method requires much more stringent assumptions on its parameters than the similar constructor from the FieldRotation class. As far as the FieldRotation constructor is concerned, the v\u2082 vector from the second pair can be slightly misaligned. The FieldRotation constructor will compensate for this misalignment and create a rotation that ensure v\u2081 = r(u\u2081) and v\u2082 \u2208 plane (r(u\u2081), r(u\u2082)). THIS IS NOT TRUE ANYMORE IN THIS CLASS! As derivatives are involved and must be preserved, this constructor works only if the two pairs are fully consistent, i.e. if a rotation exists that fulfill all the requirements: v\u2081 = r(u\u2081), v\u2082 = r(u\u2082), dv\u2081/dt = dr(u\u2081)/dt, dv\u2082/dt = dr(u\u2082)/dt, d²v\u2081/dt² = d²r(u\u2081)/dt², d²v\u2082/dt² = d²r(u\u2082)/dt².
    
    Parameters:
    
    u1 - first vector of the origin pair
    
    u2 - second vector of the origin pair
    
    v1 - desired image of u1 by the rotation
    
    v2 - desired image of u2 by the rotation
    
    tolerance - relative tolerance factor used to check singularities
    
    Throws:
    
    OrekitException - if the vectors are inconsistent for the rotation to be found (null, aligned, ...)
  - FieldAngularCoordinates
```
public FieldAngularCoordinates(Field<T> field,
                               AngularCoordinates ang)
```
    Builds a FieldAngularCoordinates from a field and a regular AngularCoordinates.
    
    Parameters:
    
    field - field for the components
    
    ang - AngularCoordinates to convert
  - FieldAngularCoordinates
```
public FieldAngularCoordinates(FieldRotation<FieldDerivativeStructure<T>> r)
```
    Builds a FieldAngularCoordinates from a FieldRotation<FieldDerivativeStructure>.
    The rotation components must have time as their only derivation parameter and have consistent derivation orders.
    
    Parameters:
    
    r - rotation with time-derivatives embedded within the coordinates
    
    Since:
    
    9.2
- Method Detail
  - getIdentity
```
public static <T extends RealFieldElement<T>> FieldAngularCoordinates<T> getIdentity(Field<T> field)
```
    Fixed orientation parallel with reference frame (identity rotation, zero rotation rate and acceleration).
    
    Type Parameters:
    
    T - the type of the field elements
    
    Parameters:
    
    field - field for the components
    
    Returns:
    
    a new fixed orientation parallel with reference frame
  - toDerivativeStructureRotation
```
public FieldRotation<FieldDerivativeStructure<T>> toDerivativeStructureRotation(int order)
                                                                         throws OrekitException
```
    Transform the instance to a FieldRotation<FieldDerivativeStructure>.
    The DerivativeStructure coordinates correspond to time-derivatives up to the user-specified order.
    
    Parameters:
    
    order - derivation order for the vector components
    
    Returns:
    
    rotation with time-derivatives embedded within the coordinates
    
    Throws:
    
    OrekitException - if the user specified order is too large
    
    Since:
    
    9.2
  - estimateRate
```
public static <T extends RealFieldElement<T>> FieldVector3D<T> estimateRate(FieldRotation<T> start,
                                                                            FieldRotation<T> end,
                                                                            double dt)
```
    Estimate rotation rate between two orientations.
    Estimation is based on a simple fixed rate rotation during the time interval between the two orientations.
    
    Type Parameters:
    
    T - the type of the field elements
    
    Parameters:
    
    start - start orientation
    
    end - end orientation
    
    dt - time elapsed between the dates of the two orientations
    
    Returns:
    
    rotation rate allowing to go from start to end orientations
  - estimateRate
```
public static <T extends RealFieldElement<T>> FieldVector3D<T> estimateRate(FieldRotation<T> start,
                                                                            FieldRotation<T> end,
                                                                            T dt)
```
    Estimate rotation rate between two orientations.
    Estimation is based on a simple fixed rate rotation during the time interval between the two orientations.
    
    Type Parameters:
    
    T - the type of the field elements
    
    Parameters:
    
    start - start orientation
    
    end - end orientation
    
    dt - time elapsed between the dates of the two orientations
    
    Returns:
    
    rotation rate allowing to go from start to end orientations
  - revert
```
public FieldAngularCoordinates<T> revert()
```
    Revert a rotation / rotation rate / rotation acceleration triplet.
    Build a triplet which reverse the effect of another triplet.
    
    Returns:
    
    a new triplet whose effect is the reverse of the effect of the instance
  - shiftedBy
```
public FieldAngularCoordinates<T> shiftedBy(double dt)
```
    Get a time-shifted state.
    The state can be slightly shifted to close dates. This shift is based on a simple quadratic model. It is not intended as a replacement for proper attitude propagation but should be sufficient for either small time shifts or coarse accuracy.
    
    Parameters:
    
    dt - time shift in seconds
    
    Returns:
    
    a new state, shifted with respect to the instance (which is immutable)
  - shiftedBy
```
public FieldAngularCoordinates<T> shiftedBy(T dt)
```
    Get a time-shifted state.
    The state can be slightly shifted to close dates. This shift is based on a simple quadratic model. It is not intended as a replacement for proper attitude propagation but should be sufficient for either small time shifts or coarse accuracy.
    
    Parameters:
    
    dt - time shift in seconds
    
    Returns:
    
    a new state, shifted with respect to the instance (which is immutable)
  - getRotation
```
public FieldRotation<T> getRotation()
```
    Get the rotation.
    
    Returns:
    
    the rotation.
  - getRotationRate
```
public FieldVector3D<T> getRotationRate()
```
    Get the rotation rate.
    
    Returns:
    
    the rotation rate vector (rad/s).
  - getRotationAcceleration
```
public FieldVector3D<T> getRotationAcceleration()
```
    Get the rotation acceleration.
    
    Returns:
    
    the rotation acceleration vector dΩ/dt (rad²/s²).
  - addOffset
```
public FieldAngularCoordinates<T> addOffset(FieldAngularCoordinates<T> offset)
```
    Add an offset from the instance.
    We consider here that the offset rotation is applied first and the instance is applied afterward. Note that angular coordinates do not commute under this operation, i.e. a.addOffset(b) and b.addOffset(a) lead to different results in most cases.
    
    The two methods addOffset and subtractOffset are designed so that round trip applications are possible. This means that both ac1.subtractOffset(ac2).addOffset(ac2) and ac1.addOffset(ac2).subtractOffset(ac2) return angular coordinates equal to ac1.
    
    Parameters:
    
    offset - offset to subtract
    
    Returns:
    
    new instance, with offset subtracted
    
    See Also:
    
    subtractOffset(FieldAngularCoordinates)
  - subtractOffset
```
public FieldAngularCoordinates<T> subtractOffset(FieldAngularCoordinates<T> offset)
```
    Subtract an offset from the instance.
    We consider here that the offset Rotation is applied first and the instance is applied afterward. Note that angular coordinates do not commute under this operation, i.e. a.subtractOffset(b) and b.subtractOffset(a) lead to different results in most cases.
    
    The two methods addOffset and subtractOffset are designed so that round trip applications are possible. This means that both ac1.subtractOffset(ac2).addOffset(ac2) and ac1.addOffset(ac2).subtractOffset(ac2) return angular coordinates equal to ac1.
    
    Parameters:
    
    offset - offset to subtract
    
    Returns:
    
    new instance, with offset subtracted
    
    See Also:
    
    addOffset(FieldAngularCoordinates)
  - toAngularCoordinates
```
public AngularCoordinates toAngularCoordinates()
```
    Convert to a regular angular coordinates.
    
    Returns:
    
    a regular angular coordinates
  - applyTo
```
public FieldPVCoordinates<T> applyTo(PVCoordinates pv)
```
    Apply the rotation to a pv coordinates.
    
    Parameters:
    
    pv - vector to apply the rotation to
    
    Returns:
    
    a new pv coordinates which is the image of u by the rotation
  - applyTo
```
public TimeStampedFieldPVCoordinates<T> applyTo(TimeStampedPVCoordinates pv)
```
    Apply the rotation to a pv coordinates.
    
    Parameters:
    
    pv - vector to apply the rotation to
    
    Returns:
    
    a new pv coordinates which is the image of u by the rotation
  - applyTo
```
public FieldPVCoordinates<T> applyTo(FieldPVCoordinates<T> pv)
```
    Apply the rotation to a pv coordinates.
    
    Parameters:
    
    pv - vector to apply the rotation to
    
    Returns:
    
    a new pv coordinates which is the image of u by the rotation
    
    Since:
    
    9.0
  - applyTo
```
public TimeStampedFieldPVCoordinates<T> applyTo(TimeStampedFieldPVCoordinates<T> pv)
```
    Apply the rotation to a pv coordinates.
    
    Parameters:
    
    pv - vector to apply the rotation to
    
    Returns:
    
    a new pv coordinates which is the image of u by the rotation
    
    Since:
    
    9.0
  - getModifiedRodrigues
```
public T[][] getModifiedRodrigues(double sign)
```
    Convert rotation, rate and acceleration to modified Rodrigues vector and derivatives.
    The modified Rodrigues vector is tan(θ/4) u where θ and u are the rotation angle and axis respectively.
    
    Parameters:
    
    sign - multiplicative sign for quaternion components
    
    Returns:
    
    modified Rodrigues vector and derivatives (vector on row 0, first derivative on row 1, second derivative on row 2)
    
    Since:
    
    9.0
    
    See Also:
    
    createFromModifiedRodrigues(RealFieldElement[][])
  - createFromModifiedRodrigues
```
public static <T extends RealFieldElement<T>> FieldAngularCoordinates<T> createFromModifiedRodrigues(T[][] r)
```
    Convert a modified Rodrigues vector and derivatives to angular coordinates.
    
    Type Parameters:
    
    T - the type of the field elements
    
    Parameters:
    
    r - modified Rodrigues vector (with first and second times derivatives)
    
    Returns:
    
    angular coordinates
    
    Since:
    
    9.0
    
    See Also:
    
    getModifiedRodrigues(double)

Class FieldAngularCoordinates<T extends RealFieldElement<T>>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FieldAngularCoordinates

FieldAngularCoordinates

FieldAngularCoordinates

FieldAngularCoordinates

FieldAngularCoordinates

Method Detail

getIdentity

toDerivativeStructureRotation

estimateRate

estimateRate

revert

shiftedBy

shiftedBy

getRotation

getRotationRate

getRotationAcceleration

addOffset

subtractOffset

toAngularCoordinates

applyTo

applyTo

applyTo

applyTo

getModifiedRodrigues

createFromModifiedRodrigues