fr.cnes.sirius.patrius.orbits

Class AnomalyUtils

java.lang.Object

fr.cnes.sirius.patrius.orbits.AnomalyUtils

public final class AnomalyUtils
extends Object

Utility class describing anomalies conversion features to switch between mean, eccentric and true anomalies.

Specific methods for elliptic or hyperbolic orbits can be used.
Specific methods are available depending if the eccentricity is expressed with one component (e) or two components (ex / ey).

Since:

4.17

Author:

Thibaut BONIT

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_ITERATIONS_DEFAULT_VALUE Default value for the maximum number of iterations for convergence algorithms.

Method Summary

Modifier and Type	Method and Description
static double	eccentricToMeanElliptic(double e, double eccentricAnomaly) Convert eccentric anomaly → mean anomaly (elliptic orbit).
static double	eccentricToMeanElliptic(double ex, double ey, double alphaE) Convert eccentric latitude/longitude argument → mean latitude/longitude argument (elliptic orbit).
static double	eccentricToMeanHyperbolic(double e, double eccentricAnomaly) Convert eccentric anomaly → mean anomaly (hyperbolic orbit).
static double	eccentricToMeanHyperbolic(double ex, double ey, double alphaE) Convert eccentric latitude/longitude argument → mean latitude/longitude argument (hyperbolic orbit).
static double	eccentricToTrueElliptic(double e, double eccentricAnomaly) Convert eccentric anomaly → true anomaly (elliptic orbit).
static double	eccentricToTrueElliptic(double ex, double ey, double alphaE) Convert eccentric latitude/longitude argument → true latitude/longitude argument (elliptic orbit).
static double	eccentricToTrueHyperbolic(double e, double eccentricAnomaly) Convert eccentric anomaly → true anomaly (hyperbolic orbit).
static double	eccentricToTrueHyperbolic(double ex, double ey, double alphaE) Convert eccentric latitude/longitude argument → true latitude/longitude argument (hyperbolic orbit).
static Pair<Double,PositionAngle>	getInitializedValue(double meanVal, double eccentricVal, double trueVal) Evaluate which of the three values is initialized ({@code !
static double[]	initializeValues(double value, PositionAngle type) Return an array describing the given value according to the given type and Double.NaN for the other elements.
static double	meanToEccentricElliptic(double e, double meanAnomaly) Convert mean anomaly → eccentric anomaly (elliptic orbit).
static double	meanToEccentricElliptic(double ex, double ey, double alphaM) Convert mean latitude/longitude argument → eccentric latitude/longitude argument (elliptic orbit).
static double	meanToEccentricHyperbolic(double e, double meanAnomaly) Convert mean anomaly → eccentric anomaly (hyperbolic orbit).
static double	meanToEccentricHyperbolic(double ex, double ey, double alphaM) Convert mean latitude/longitude argument → eccentric latitude/longitude argument (hyperbolic orbit).
static void	setMaxIterations(int maxIterations) Setter for the maximum number of iterations for convergence algorithms.
static double	trueToEccentricElliptic(double e, double trueAnomaly) Convert true anomaly → eccentric anomaly (elliptic orbit).
static double	trueToEccentricElliptic(double ex, double ey, double alphaV) Convert true latitude/longitude argument → eccentric latitude/longitude argument (elliptic orbit).
static double	trueToEccentricHyperbolic(double e, double trueAnomaly) Convert true anomaly → eccentric anomaly (hyperbolic orbit).
static double	trueToEccentricHyperbolic(double ex, double ey, double alphaV) Convert true latitude/longitude argument → eccentric latitude/longitude argument (hyperbolic orbit).

Methods inherited from class java.lang.Object

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

Field Detail

MAX_ITERATIONS_DEFAULT_VALUE

public static final int MAX_ITERATIONS_DEFAULT_VALUE

Default value for the maximum number of iterations for convergence algorithms.

See Also:

Constant Field Values

Method Detail

meanToEccentricElliptic

public static double meanToEccentricElliptic(double e,
                                             double meanAnomaly)

Convert mean anomaly → eccentric anomaly (elliptic orbit).

The algorithm used here for solving Kepler equation has been published in: "Procedures for solving Kepler's Equation", A. W. Odell and R. H. Gooding, Celestial Mechanics 38 (1986) 307-334

Parameters:

e - eccentricity (e >= 0)

meanAnomaly - mean anomaly (rad)

Returns:

the eccentric anomaly (rad)

meanToEccentricElliptic

public static double meanToEccentricElliptic(double ex,
                                             double ey,
                                             double alphaM)

Convert mean latitude/longitude argument → eccentric latitude/longitude argument (elliptic orbit).

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaM - = M + ω mean latitude/longitude argument (rad)

Returns:

the eccentric latitude/longitude argument (rad)

Throws:

ConvergenceException - if the algorithm fails to converge

meanToEccentricHyperbolic

public static double meanToEccentricHyperbolic(double e,
                                               double meanAnomaly)

Convert mean anomaly → eccentric anomaly (hyperbolic orbit).

The algorithm used here for solving hyperbolic Kepler equation is a naive initialization and classical Halley method for iterations.

Parameters:

e - eccentricity (e >= 0)

meanAnomaly - mean anomaly (rad)

Returns:

the eccentric anomaly (rad)

Throws:

ConvergenceException - if the algorithm fails to converge

meanToEccentricHyperbolic

public static double meanToEccentricHyperbolic(double ex,
                                               double ey,
                                               double alphaM)

Convert mean latitude/longitude argument → eccentric latitude/longitude argument (hyperbolic orbit).

The algorithm used here for solving hyperbolic Kepler equation is a naive initialization and classical Halley method for iterations adapted to circular parameters.

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaM - mean latitude/longitude argument (rad)

Returns:

the eccentric latitude/longitude argument (rad)

Throws:

ConvergenceException - if the algorithm fails to converge

trueToEccentricElliptic

public static double trueToEccentricElliptic(double e,
                                             double trueAnomaly)

Convert true anomaly → eccentric anomaly (elliptic orbit).

Parameters:

e - eccentricity (e >= 0)

trueAnomaly - true anomaly (rad)

Returns:

the eccentric anomaly (rad)

trueToEccentricElliptic

public static double trueToEccentricElliptic(double ex,
                                             double ey,
                                             double alphaV)

Convert true latitude/longitude argument → eccentric latitude/longitude argument (elliptic orbit).

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaV - true latitude/longitude argument (rad)

Returns:

the eccentric latitude/longitude argument (rad)

trueToEccentricHyperbolic

public static double trueToEccentricHyperbolic(double e,
                                               double trueAnomaly)

Convert true anomaly → eccentric anomaly (hyperbolic orbit).

Parameters:

e - eccentricity (e >= 0)

trueAnomaly - true anomaly (rad)

Returns:

the eccentric anomaly (rad)

trueToEccentricHyperbolic

public static double trueToEccentricHyperbolic(double ex,
                                               double ey,
                                               double alphaV)

Convert true latitude/longitude argument → eccentric latitude/longitude argument (hyperbolic orbit).

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaV - true latitude/longitude argument (rad)

Returns:

the eccentric latitude/longitude argument (rad)

eccentricToMeanElliptic

public static double eccentricToMeanElliptic(double e,
                                             double eccentricAnomaly)

Convert eccentric anomaly → mean anomaly (elliptic orbit).

Parameters:

e - eccentricity (e >= 0)

eccentricAnomaly - eccentric anomaly (rad)

Returns:

the mean anomaly (rad)

eccentricToMeanElliptic

public static double eccentricToMeanElliptic(double ex,
                                             double ey,
                                             double alphaE)

Convert eccentric latitude/longitude argument → mean latitude/longitude argument (elliptic orbit).

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaE - eccentric argument of latitude/longitude (rad)

Returns:

the mean latitude/longitude argument (rad)

eccentricToMeanHyperbolic

public static double eccentricToMeanHyperbolic(double e,
                                               double eccentricAnomaly)

Convert eccentric anomaly → mean anomaly (hyperbolic orbit).

Parameters:

e - eccentricity (e >= 0)

eccentricAnomaly - eccentric anomaly (rad)

Returns:

the mean anomaly (rad)

eccentricToMeanHyperbolic

public static double eccentricToMeanHyperbolic(double ex,
                                               double ey,
                                               double alphaE)

Convert eccentric latitude/longitude argument → mean latitude/longitude argument (hyperbolic orbit).

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaE - eccentric argument of latitude/longitude (rad)

Returns:

the mean latitude/longitude argument (rad)

eccentricToTrueElliptic

public static double eccentricToTrueElliptic(double e,
                                             double eccentricAnomaly)

Convert eccentric anomaly → true anomaly (elliptic orbit).

Parameters:

e - eccentricity (e >= 0)

eccentricAnomaly - eccentric anomaly (rad)

Returns:

the true anomaly (rad)

eccentricToTrueElliptic

public static double eccentricToTrueElliptic(double ex,
                                             double ey,
                                             double alphaE)

Convert eccentric latitude/longitude argument → true latitude/longitude argument (elliptic orbit).

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaE - eccentric argument of latitude/longitude (rad)

Returns:

the true latitude/longitude argument (rad)

eccentricToTrueHyperbolic

public static double eccentricToTrueHyperbolic(double e,
                                               double eccentricAnomaly)

Convert eccentric anomaly → true anomaly (hyperbolic orbit).

Parameters:

e - eccentricity (e >= 0)

eccentricAnomaly - hyperbolic eccentric anomaly (rad)

Returns:

the true anomaly (rad)

eccentricToTrueHyperbolic

public static double eccentricToTrueHyperbolic(double ex,
                                               double ey,
                                               double alphaE)

Convert eccentric latitude/longitude argument → true latitude/longitude argument (hyperbolic orbit).

Parameters:

ex - e cos(ω), first component of circular eccentricity vector

ey - e sin(ω), second component of circular eccentricity vector

alphaE - eccentric argument of latitude/longitude (rad)

Returns:

the true latitude/longitude argument (rad)

initializeValues

public static double[] initializeValues(double value,
                                        PositionAngle type)

Return an array describing the given value according to the given type and Double.NaN for the other elements.

Array index:

• [0]: Mean value
• [1]: Eccentric value
• [2]: True value

Parameters:

value - Value

type - Type

Returns:

the array describing the mean, eccentric and true values

Throws:

IllegalArgumentException - if the provided value is Double.NaN

getInitializedValue

public static Pair<Double,PositionAngle> getInitializedValue(double meanVal,
                                                             double eccentricVal,
                                                             double trueVal)

Evaluate which of the three values is initialized (!= Double.NaN), then return it with its associated type.
The first initialized value is returned, evaluated in this order: true, mean, eccentric.

Note: the method purpose is to avoid unnecessary computations to use already initialized values.
In that matter computation methods should NEVER be called to provide the inputs.
To be more explicit through an example, don't call "getInitializedValue(getMeanAnomaly(), getEccentricAnomaly(), getTrueAnomaly())", but instead "getInitializedValue(this.meanAnomaly, this.eccentricAnomaly, this.trueAnomaly)"

Parameters:

meanVal - Mean value

eccentricVal - Eccentric value

trueVal - True value

Returns:

the first initialized value and its type

setMaxIterations

public static void setMaxIterations(int maxIterations)

Setter for the maximum number of iterations for convergence algorithms.

Parameters:

maxIterations - the value to set