astro

Class SunPosition

java.lang.Object

astro.SunPosition

All Implemented Interfaces:

SolarPosition

public class SunPosition
extends Object
implements SolarPosition

A class calculating the position of the moon. It is based on the AstroLib package provided by Mark Huss. He gives no hint about the precision of the formulas used, but from a first test I estimate an accuracy of down to one arc minute.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SunPosition.Test Testing purpose mainly.

Nested classes/interfaces inherited from interface astro.SolarPosition

SolarPosition.Plato1, SolarPosition.Plato2

Field Summary

Fields

Modifier and Type	Field and Description
private static double	ASUN The constant coefficient.
private static double	BSUN The linear coefficient.
private Date	when The date for which the sun position is valid.

Constructor Summary

Constructors

Constructor and Description
SunPosition() Constructs a new moon position object.
SunPosition(Date fordate) Constructs a new moon position object for the given date.

Method Summary

Modifier and Type	Method and Description
double	getDec() Returns the declination of the moon for the center of the earth in radians.
double	getDistance()
double	getEclipticalLongitude() Returns the ecliptical longitude of the Sun for the center of the earth in radians.
double	getRa() Returns the right ascension of the moon for the center of the earth in radians.
void	setDate(Date fordate) Sets a (new) date for the moon position object.

Methods inherited from class java.lang.Object

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

Field Detail

ASUN

private static final double ASUN

The constant coefficient.

See Also:

Constant Field Values

BSUN

private static final double BSUN

The linear coefficient.

See Also:

Constant Field Values

when

private Date when

The date for which the sun position is valid.

Constructor Detail

SunPosition

public SunPosition()

Constructs a new moon position object. The position data may only be retrieved after a date was set.

SunPosition

public SunPosition(Date fordate)

Constructs a new moon position object for the given date. Data retrieval may proceed at once.

Method Detail

setDate

public void setDate(Date fordate)

Sets a (new) date for the moon position object. Right ascension and declination are invalidated.

Specified by:

setDate in interface SolarPosition

getEclipticalLongitude

public double getEclipticalLongitude()

Returns the ecliptical longitude of the Sun for the center of the earth in radians.

Specified by:

getEclipticalLongitude in interface SolarPosition

Throws:

IllegalArgumentException - If no date was set.

getDistance

public double getDistance()

getRa

public double getRa()

Returns the right ascension of the moon for the center of the earth in radians.

Specified by:

getRa in interface SolarPosition

Throws:

IllegalArgumentException - If no date was set.

getDec

public double getDec()

Returns the declination of the moon for the center of the earth in radians.

Specified by:

getDec in interface SolarPosition

Throws:

IllegalArgumentException - If no date was set.