public class TimeStampedAngularCoordinates extends AngularCoordinates implements TimeStamped
IDENTITY| Constructor and Description |
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TimeStampedAngularCoordinates(AbsoluteDate date,
FieldRotation<DerivativeStructure> r)
Builds a TimeStampedAngularCoordinates from a
FieldRotation<DerivativeStructure>. |
TimeStampedAngularCoordinates(AbsoluteDate date,
PVCoordinates u,
PVCoordinates v)
Build one of the rotations that transform one pv coordinates into another one.
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TimeStampedAngularCoordinates(AbsoluteDate date,
PVCoordinates u1,
PVCoordinates u2,
PVCoordinates v1,
PVCoordinates v2,
double tolerance)
Build the rotation that transforms a pair of pv coordinates into another pair.
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TimeStampedAngularCoordinates(AbsoluteDate date,
Rotation rotation,
Vector3D rotationRate,
Vector3D rotationAcceleration)
Builds a rotation/rotation rate pair.
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| Modifier and Type | Method and Description |
|---|---|
TimeStampedAngularCoordinates |
addOffset(AngularCoordinates offset)
Add an offset from the instance.
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AbsoluteDate |
getDate()
Get the date.
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static TimeStampedAngularCoordinates |
interpolate(AbsoluteDate date,
AngularDerivativesFilter filter,
Collection<TimeStampedAngularCoordinates> sample)
Interpolate angular coordinates.
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TimeStampedAngularCoordinates |
revert()
Revert a rotation/rotation rate pair.
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TimeStampedAngularCoordinates |
shiftedBy(double dt)
Get a time-shifted state.
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TimeStampedAngularCoordinates |
subtractOffset(AngularCoordinates offset)
Subtract an offset from the instance.
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applyTo, applyTo, createFromModifiedRodrigues, estimateRate, getModifiedRodrigues, getRotation, getRotationAcceleration, getRotationRate, interpolate, toDerivativeStructureRotationpublic TimeStampedAngularCoordinates(AbsoluteDate date, Rotation rotation, Vector3D rotationRate, Vector3D rotationAcceleration)
date - coordinates daterotation - rotationrotationRate - rotation rate Ω (rad/s)rotationAcceleration - rotation acceleration dΩ/dt (rad²/s²)public TimeStampedAngularCoordinates(AbsoluteDate date, PVCoordinates u1, PVCoordinates u2, PVCoordinates v1, PVCoordinates v2, double tolerance) throws OrekitException
WARNING! This method requires much more stringent assumptions on
its parameters than the similar constructor from the Rotation class.
As far as the Rotation constructor is concerned, the v₂ vector from
the second pair can be slightly misaligned. The Rotation constructor will
compensate for this misalignment and create a rotation that ensure v₁ = r(u₁) and v₂ ∈ plane (r(u₁), r(u₂)). 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: v₁ = r(u₁), v₂ = r(u₂), dv₁/dt = dr(u₁)/dt, dv₂/dt
= dr(u₂)/dt, d²v₁/dt² = d²r(u₁)/dt², d²v₂/dt² = d²r(u₂)/dt².
date - coordinates dateu1 - first vector of the origin pairu2 - second vector of the origin pairv1 - desired image of u1 by the rotationv2 - desired image of u2 by the rotationtolerance - relative tolerance factor used to check singularitiesOrekitException - if the vectors components cannot be converted to
DerivativeStructure with proper orderpublic TimeStampedAngularCoordinates(AbsoluteDate date, PVCoordinates u, PVCoordinates v) throws OrekitException
Except for a possible scale factor, if the instance were applied to the vector u it will produce the vector v. There is an infinite number of such rotations, this constructor choose the one with the smallest associated angle (i.e. the one whose axis is orthogonal to the (u, v) plane). If u and v are collinear, an arbitrary rotation axis is chosen.
date - coordinates dateu - origin vectorv - desired image of u by the rotationOrekitException - if the vectors components cannot be converted to
DerivativeStructure with proper orderpublic TimeStampedAngularCoordinates(AbsoluteDate date, FieldRotation<DerivativeStructure> r)
FieldRotation<DerivativeStructure>.
The rotation components must have time as their only derivation parameter and have consistent derivation orders.
date - coordinates dater - rotation with time-derivatives embedded within the coordinatespublic AbsoluteDate getDate()
getDate in interface TimeStampedpublic TimeStampedAngularCoordinates revert()
revert in class AngularCoordinatespublic TimeStampedAngularCoordinates shiftedBy(double dt)
The state can be slightly shifted to close dates. This shift is based on a simple linear model. It is not intended as a replacement for proper attitude propagation but should be sufficient for either small time shifts or coarse accuracy.
shiftedBy in interface TimeShiftable<AngularCoordinates>shiftedBy in class AngularCoordinatesdt - time shift in secondspublic TimeStampedAngularCoordinates addOffset(AngularCoordinates offset)
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.
addOffset in class AngularCoordinatesoffset - offset to subtractsubtractOffset(AngularCoordinates)public TimeStampedAngularCoordinates subtractOffset(AngularCoordinates offset)
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.
subtractOffset in class AngularCoordinatesoffset - offset to subtractaddOffset(AngularCoordinates)public static TimeStampedAngularCoordinates interpolate(AbsoluteDate date, AngularDerivativesFilter filter, Collection<TimeStampedAngularCoordinates> sample) throws OrekitException
The interpolated instance is created by polynomial Hermite interpolation on Rodrigues vector ensuring rotation rate remains the exact derivative of rotation.
This method is based on Sergei Tanygin's paper Attitude Interpolation, changing the norm of the vector to match the modified Rodrigues vector as described in Malcolm D. Shuster's paper A Survey of Attitude Representations. This change avoids the singularity at π. There is still a singularity at 2π, which is handled by slightly offsetting all rotations when this singularity is detected.
Note that even if first and second time derivatives (rotation rates and acceleration) from sample can be ignored, the interpolated instance always includes interpolated derivatives. This feature can be used explicitly to compute these derivatives when it would be too complex to compute them from an analytical formula: just compute a few sample points from the explicit formula and set the derivatives to zero in these sample points, then use interpolation to add derivatives consistent with the rotations.
date - interpolation datefilter - filter for derivatives from the sample to use in interpolationsample - sample points on which interpolation should be doneOrekitException - if the number of point is too small for interpolatingCopyright © 2002-2015 CS Systèmes d'information. All rights reserved.