org.orekit.propagation.semianalytical.dsst.utilities

Class FieldAuxiliaryElements<T extends RealFieldElement<T>>

java.lang.Object

org.orekit.propagation.semianalytical.dsst.utilities.FieldAuxiliaryElements<T>

public class FieldAuxiliaryElements<T extends RealFieldElement<T>>
extends Object

Container class for common parameters used by all DSST forces.

Most of them are defined in Danielson paper at § 2.1.

Field Summary

Fields

Modifier and Type	Field and Description
static double	TWO_PI \(2\pi\) .

Constructor Summary

Constructors

Constructor and Description
FieldAuxiliaryElements(FieldOrbit<T> orbit, int retrogradeFactor) Simple constructor.

Method Summary

Modifier and Type	Method and Description
T	getAlpha() Get direction cosine α for central body.
T	getB() Get B = sqrt(1 - e²).
T	getBeta() Get direction cosine β for central body.
T	getC() Get C = 1 + p² + q².
FieldAbsoluteDate<T>	getDate() Get the date of the orbit.
T	getEcc() Get the eccentricity.
Frame	getFrame() Get the definition frame of the orbit.
T	getGamma() Get direction cosine γ for central body.
T	getH() Get the y component of eccentricity vector.
T	getK() Get the x component of eccentricity vector.
T	getKeplerianPeriod() Get the Keplerian period.
T	getLe() Get the eccentric longitude.
T	getLM() Get the mean longitude.
T	getLv() Get the true longitude.
T	getMeanMotion() Get the Keplerian mean motion.
T	getP() Get the y component of inclination vector.
T	getQ() Get the x component of inclination vector.
int	getRetrogradeFactor() Get the retrograde factor.
T	getSma() Get the semi-major axis.
FieldVector3D<T>	getVectorF() Get equinoctial frame vector f.
FieldVector3D<T>	getVectorG() Get equinoctial frame vector g.
FieldVector3D<T>	getVectorW() Get equinoctial frame vector w.
T	normalizeAngle(T a, T center) Normalize an angle in a 2π wide interval around a center value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TWO_PI

public static final double TWO_PI

\(2\pi\) .

See Also:

Constant Field Values

Constructor Detail

FieldAuxiliaryElements

public FieldAuxiliaryElements(FieldOrbit<T> orbit,
                              int retrogradeFactor)

Simple constructor.

Parameters:

orbit - related mean orbit for auxiliary elements

retrogradeFactor - retrograde factor I [Eq. 2.1.2-(2)]

Method Detail

normalizeAngle

public T normalizeAngle(T a,
                        T center)

Normalize an angle in a 2π wide interval around a center value.

This method has three main uses:

• normalize an angle between 0 and 2π:
  a = MathUtils.normalizeAngle(a, FastMath.PI);
• normalize an angle between -π and +π
  a = MathUtils.normalizeAngle(a, 0.0);
• compute the angle between two defining angular positions:
  angle = MathUtils.normalizeAngle(end, start) - start;

Note that due to numerical accuracy and since π cannot be represented exactly, the result interval is closed, it cannot be half-closed as would be more satisfactory in a purely mathematical view.

Parameters:

a - angle to normalize

center - center of the desired 2π interval for the result

Returns:

a-2kπ with integer k and center-π <= a-2kπ <= center+π

getDate

public FieldAbsoluteDate<T> getDate()

Get the date of the orbit.

Returns:

the date

getFrame

public Frame getFrame()

Get the definition frame of the orbit.

Returns:

the definition frame

getEcc

public T getEcc()

Get the eccentricity.

Returns:

ecc

getMeanMotion

public T getMeanMotion()

Get the Keplerian mean motion.

Returns:

n

getKeplerianPeriod

public T getKeplerianPeriod()

Get the Keplerian period.

Returns:

period

getSma

public T getSma()

Get the semi-major axis.

Returns:

the semi-major axis a

getK

public T getK()

Get the x component of eccentricity vector.

This element called k in DSST corresponds to ex for the EquinoctialOrbit

Returns:

k

getH

public T getH()

Get the y component of eccentricity vector.

This element called h in DSST corresponds to ey for the EquinoctialOrbit

Returns:

h

getQ

public T getQ()

Get the x component of inclination vector.

This element called q in DSST corresponds to hx for the EquinoctialOrbit

Returns:

q

getP

public T getP()

Get the y component of inclination vector.

This element called p in DSST corresponds to hy for the EquinoctialOrbit

Returns:

p

getLM

public T getLM()

Get the mean longitude.

Returns:

lm

getLv

public T getLv()

Get the true longitude.

Returns:

lv

getLe

public T getLe()

Get the eccentric longitude.

Returns:

le

getRetrogradeFactor

public int getRetrogradeFactor()

Get the retrograde factor.

Returns:

the retrograde factor I

getB

public T getB()

Get B = sqrt(1 - e²).

Returns:

B

getC

public T getC()

Get C = 1 + p² + q².

Returns:

C

getVectorF

public FieldVector3D<T> getVectorF()

Get equinoctial frame vector f.

Returns:

f vector

getVectorG

public FieldVector3D<T> getVectorG()

Get equinoctial frame vector g.

Returns:

g vector

getVectorW

public FieldVector3D<T> getVectorW()

Get equinoctial frame vector w.

Returns:

w vector

getAlpha

public T getAlpha()

Get direction cosine α for central body.

Returns:

α

getBeta

public T getBeta()

Get direction cosine β for central body.

Returns:

β

getGamma

public T getGamma()

Get direction cosine γ for central body.

Returns:

γ