solarGeom

Solar geometery

A set of methods that compute solar geometry objects. This is a Python implementation of Javier Corripio’s R-package ‘insol’. Documented here:

https://doi.org/10.1080/713811744

validated against original R-package code from Corripio

Example:

Attributes:

Todo:

solarGeom.declination(jd)

Computes the declination of the Sun for a given Julian Day.

jd: Julian Day and decimal fraction. cat(“USAGE: declination(jd)

“)

solarGeom.eqtime(jd)

Computes the equation of time for a given Julian Day.

jd: Julian Day and decimal fraction. cat(“USAGE: eqtime(jd)

“)

solarGeom.hourangle(jd, longitude, timezone)

Hour angle, internal function for solar position.

jd: Julian Day and decimal fraction. latitude: Latitude of observer in degrees and decimal fraction. longitude: Longitude of observer in degrees and decimal fraction. timezone: in hours, west of Greenwich is negative eg CH is “1”

cat(“USAGE: hourangle(jd,longitude,timezone)

julian day, degrees, hours.

Return radians

“)

solarGeom.hourangleMD(jd, longitude, timezone, statsize, timesize)

Hour angle, internal function for solar position.

THIS IS MLTIDIMENSIONAL VERSION LONGITUDE/TIMEZONE are vectors (of stations) not scalars

jd: Julian Day and decimal fraction. latitude: Latitude of observer in degrees and decimal fraction. longitude: Longitude of observer in degrees and decimal fraction. timezone: in hours, west of Greenwich is negative eg CH is “1”

cat(“USAGE: hourangle(jd,longitude,timezone)

julian day, degrees, hours.

Return radians

“)

solarGeom.normalvector(slope, aspect)

Calculates a unit vector normal to a surface defined by slope inclination and slope orientation.

slope: slope of position in degrees aspect: aspect of position in degrees print(“USAGE: normalvector(slope,aspect)

“)

solarGeom.sunpos(sunv)

Returns a matrix of azimuth and zenith angles of the sun given the unit vectors from the observer to the direction of the sun. Plus sun elevation.

sunv: sunvector #print(“USAGE: sunpos(sunvector) 3D vector”)

solarGeom.sunposMD(sunx, suny, sunz)

Returns a matrix of azimuth and zenith angles of the sun given the unit vectors from the observer to the direction of the sun. Plus sun elevation.

sunv: sunvector #print(“USAGE: sunpos(sunvector) 3D vector”)

solarGeom.sunvector(jd, latitude, longitude, timezone)

Calculates a unit vector in the direction of the sun from the observer position

jd: Julian Day and decimal fraction. latitude: Latitude of observer in degrees and decimal fraction. longitude: Longitude of observer in degrees and decimal fraction. timezone: Time zone in hours, west is negative. # cat(“USAGE: sunvector(jd,latitude,longitude,timezone)

values in jd, degrees, hours

“)

solarGeom.sunvectorMD(jd, latitude, longitude, timezone, statsize, timesize)

Calculates a unit vector in the direction of the sun from the observer position

jd: Julian Day and decimal fraction. latitude: Latitude of observer in degrees and decimal fraction. longitude: Longitude of observer in degrees and decimal fraction. timezone: Time zone in hours, west is negative. # cat(“USAGE: sunvector(jd,latitude,longitude,timezone)

values in jd, degrees, hours

“)

solarGeom.to_jd(dt)

dt: python dattime object Converts a given datetime object (dt) to Julian date. Algorithm is copied from https://en.wikipedia.org/wiki/Julian_day All variable names are consistentdatetime.datetime.now() with the notation on the wiki page.

cite:https://github.com/dannyzed/julian/blob/master/julian/julian.py

test : dt = datetime.datetime.now()

Parameters:

• fmt –
• dt (datetime) – Datetime object to convert to MJD
• Returns –
• ------- –
• jd (float) –