net.e175.klaus.solarpositioning

Class Grena3

java.lang.Object

net.e175.klaus.solarpositioning.Grena3

public final class Grena3
extends Object

Calculate topocentric solar position, i.e. the location of the sun on the sky for a certain point in time on a certain point of the Earth's surface. This follows the no. 3 algorithm described in Grena, 'Five new algorithms for the computation of sun position from 2010 to 2110', Solar Energy 86 (2012) pp. 1323-1337. This is not a port of the C code, but a re-implementation based on the published procedure.

Author:

Klaus Brunner

Method Summary

Modifier and Type	Method and Description
static AzimuthZenithAngle	calculateSolarPosition(GregorianCalendar date, double latitude, double longitude, double deltaT) Calculate topocentric solar position, i.e.
static AzimuthZenithAngle	calculateSolarPosition(GregorianCalendar date, double latitude, double longitude, double deltaT, double pressure, double temperature) Calculate topocentric solar position, i.e.

Methods inherited from class java.lang.Object

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

Method Detail

calculateSolarPosition

public static AzimuthZenithAngle calculateSolarPosition(GregorianCalendar date,
                                                        double latitude,
                                                        double longitude,
                                                        double deltaT)

Calculate topocentric solar position, i.e. the location of the sun on the sky for a certain point in time on a certain point of the Earth's surface. This follows the no. 3 algorithm described in Grena, 'Five new algorithms for the computation of sun position from 2010 to 2110', Solar Energy 86 (2012) pp. 1323-1337. The algorithm is supposed to work for the years 2010 to 2110, with a maximum error of 0.01 degrees. This method does not perform refraction correction.

Parameters:

date - Observer's local date and time.

latitude - Observer's latitude, in degrees (negative south of equator).

longitude - Observer's longitude, in degrees (negative west of Greenwich).

deltaT - Difference between earth rotation time and terrestrial time (or Universal Time and Terrestrial Time), in seconds. See http://asa.usno.navy.mil/SecK/DeltaT.html. For the year 2015, a reasonably accurate default would be 68.

Returns:

Topocentric solar position (azimuth measured eastward from north)

See Also:

AzimuthZenithAngle

calculateSolarPosition

public static AzimuthZenithAngle calculateSolarPosition(GregorianCalendar date,
                                                        double latitude,
                                                        double longitude,
                                                        double deltaT,
                                                        double pressure,
                                                        double temperature)

Calculate topocentric solar position, i.e. the location of the sun on the sky for a certain point in time on a certain point of the Earth's surface. This follows the no. 3 algorithm described in Grena, 'Five new algorithms for the computation of sun position from 2010 to 2110', Solar Energy 86 (2012) pp. 1323-1337. The algorithm is supposed to work for the years 2010 to 2110, with a maximum error of 0.01 degrees.

Parameters:

date - Observer's local date and time.

latitude - Observer's latitude, in degrees (negative south of equator).

longitude - Observer's longitude, in degrees (negative west of Greenwich).

deltaT - Difference between earth rotation time and terrestrial time (or Universal Time and Terrestrial Time), in seconds. See http://asa.usno.navy.mil/SecK/DeltaT.html. For the year 2015, a reasonably accurate default would be 68.

pressure - Annual average local pressure, in millibars (or hectopascals). Used for refraction correction of zenith angle. If unsure, 1000 is a reasonable default.

temperature - Annual average local temperature, in degrees Celsius. Used for refraction correction of zenith angle.

Returns:

Topocentric solar position (azimuth measured eastward from north)

See Also:

AzimuthZenithAngle