net.time4j.calendar.astro

Interface SolarTime.Calculator

All Known Implementing Classes:

StdSolarCalculator

Enclosing class:

SolarTime

public static interface SolarTime.Calculator

An SPI-interface representing a facade for the calculation engine regarding sunrise or sunset.

Since:

3.34/4.29

See Also:

ServiceLoader

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	NOAA Deprecated.
static java.lang.String	SIMPLE Deprecated.

Method Summary

Modifier and Type	Method and Description
double	declination(double jde) Determines the declination of sun.
double	equationOfTime(double jde) Calculates the difference between true and mean solar time.
double	getFeature(double jde, java.lang.String nameOfFeature) Calculates a value suitable for given time and feature.
double	getGeodeticAngle(double latitude, int altitude) Calculates the additional geodetic angle due to the extra altitude of the observer.
double	getZenithAngle(double latitude, int altitude) Calculates the angle of the sun relative to the zenith at sunrise or sunset.
java.lang.String	name() Obtains the name of the calculation method.
Moment	sunrise(CalendarDate date, double latitude, double longitude, double zenith) Calculates the moment of sunrise.
Moment	sunset(CalendarDate date, double latitude, double longitude, double zenith) Calculates the moment of sunset.

Field Detail

NOAA

@Deprecated
static final java.lang.String NOAA

Deprecated.

Follows closely the algorithms published by NOAA (National Oceanic and Atmospheric Administration).

See StdSolarCalculator.NOAA.

See Also:

Constant Field Values

SIMPLE

@Deprecated
static final java.lang.String SIMPLE

Deprecated.

Simple and relatively fast but rather imprecise calculator.

See StdSolarCalculator.SIMPLE.

See Also:

Constant Field Values

Method Detail

name

java.lang.String name()

Obtains the name of the calculation method.

Returns:

String

sunrise

Moment sunrise(CalendarDate date,
               double latitude,
               double longitude,
               double zenith)

Calculates the moment of sunrise.

Parameters:

date - the local calendar date

latitude - geographical latitude in degrees, positive for North, negative for South

longitude - geographical longitude in degrees, positive for East, negative for West

zenith - the distance of the center of the sun from geographical local zenith in degrees

Returns:

moment of sunrise if it exists for given parameters else null (polar day or night)

Throws:

java.lang.IllegalArgumentException - if any parameter is out of range

sunset

Moment sunset(CalendarDate date,
              double latitude,
              double longitude,
              double zenith)

Calculates the moment of sunset.

Parameters:

date - the local calendar date

latitude - geographical latitude in degrees, positive for North, negative for South

longitude - geographical longitude in degrees, positive for East, negative for West

zenith - the distance of the center of the sun from geographical local zenith in degrees

Returns:

moment of sunset if it exists for given parameters else null (polar day or night)

Throws:

java.lang.IllegalArgumentException - if any parameter is out of range

equationOfTime

double equationOfTime(double jde)

Calculates the difference between true and mean solar time.

Parameters:

jde - julian day in ephemeris time

Returns:

value in seconds

declination

double declination(double jde)

Determines the declination of sun.

Parameters:

jde - julian day in ephemeris time

Returns:

declination of sun in degrees

getFeature

double getFeature(double jde,
                  java.lang.String nameOfFeature)

Calculates a value suitable for given time and feature.

Subclasses overriding this method document which features are supported. At least the feature "declination" must be supported by subclasses.

Parameters:

jde - julian day in ephemeris time

nameOfFeature - describes what kind of value shall be calculated

Returns:

result value or Double.NaN if the feature is not supported

See Also:

declination(double)

getGeodeticAngle

double getGeodeticAngle(double latitude,
                        int altitude)

Calculates the additional geodetic angle due to the extra altitude of the observer.

The default implementation just returns 0.0.

Parameters:

latitude - the geographical latitude in degrees

altitude - the altitude of the observer in meters

Returns:

geodetic angle correction in degrees

Since:

3.36/4.31

getZenithAngle

double getZenithAngle(double latitude,
                      int altitude)

Calculates the angle of the sun relative to the zenith at sunrise or sunset.

The default implementation just uses the standard refraction angle of 34 arc minutes, adds to it 90° and the geodetic angle correction.

Parameters:

latitude - the geographical latitude in degrees

altitude - the altitude of the observer in meters

Returns:

effective zenith angle in degrees

Since:

3.36/4.31