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

Specification:

All implementations must have a public no-arg constructor.

Method Summary

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

Method Detail

name

String name()

Obtains the name of the calculation method.

Returns:

String

sunrise

Optional<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 not present (polar day or night)

Throws:

IllegalArgumentException - if any parameter is out of range

sunset

Optional<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 not present (polar day or night)

Throws:

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

getFeature

default double getFeature(double jde,
                          String nameOfFeature)

Calculates a value suitable for given time and feature.

Subclasses overriding this method document which features are supported. At least the feature of "declination" should be supported.

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

getGeodeticAngle

default 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

default 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