README.md

CRAN Status Badge CRAN Downloads Badge

suncalc

R implementation for calculating sun position, sunlight phases (times for sunrise, sunset, dusk, etc.), moon position and lunar phase for the given location and time. Most calculations are based on the formulas given in Astronomy Answers articles about position of the sun and the planets : https://www.aa.quae.nl/en/reken/zonpositie.html

News

0.5.0 dev version

Installation

# from cran
install.packages("suncalc")
devtools::install_github("datastorm-open/suncalc") for developpement version

Use

require(suncalc)
?getSunlightTimes
getSunlightTimes(date = Sys.Date(), lat = 50.1, lon = 1.83, tz = "CET")

About suncalc

Most calculations are based on the formulas given in the excellent Astronomy Answers articles about position of the sun and the planets. You can read about different twilight phases calculated by SunCalc in the Twilight article on Wikipedia.

Reference

Sunlight times

Returns an object with the following properties (each is a Date object):

| Property | Description | | --------------- | ------------------------------------------------------------------------ | | sunrise | sunrise (top edge of the sun appears on the horizon) | | sunriseEnd | sunrise ends (bottom edge of the sun touches the horizon) | | goldenHourEnd | morning golden hour (soft light, best time for photography) ends | | solarNoon | solar noon (sun is in the highest position) | | goldenHour | evening golden hour starts | | sunsetStart | sunset starts (bottom edge of the sun touches the horizon) | | sunset | sunset (sun disappears below the horizon, evening civil twilight starts) | | dusk | dusk (evening nautical twilight starts) | | nauticalDusk | nautical dusk (evening astronomical twilight starts) | | night | night starts (dark enough for astronomical observations) | | nadir | nadir (darkest moment of the night, sun is in the lowest position) | | nightEnd | night ends (morning astronomical twilight starts) | | nauticalDawn | nautical dawn (morning nautical twilight starts) | | dawn | dawn (morning nautical twilight ends, morning civil twilight starts) |

Sun position

Returns an object with the following properties:

Moon position

Returns an object with the following properties:

Moon illumination

Returns an object with the following properties:

Moon phase value should be interpreted like this:

| Phase | Name | | -----:| --------------- | | 0 | New Moon | | | Waxing Crescent | | 0.25 | First Quarter | | | Waxing Gibbous | | 0.5 | Full Moon | | | Waning Gibbous | | 0.75 | Last Quarter | | | Waning Crescent |

By subtracting the parallacticAngle from the angle one can get the zenith angle of the moons bright limb (anticlockwise). The zenith angle can be used do draw the moon shape from the observers perspective (e.g. moon lying on its back).

Moon rise and set times

Returns an object with the following properties:

By default, it will search for moon rise and set during local user's day (frou 0 to 24 hours). If inUTC is set to true, it will instead search the specified date from 0 to 24 UTC hours.



Try the suncalc package in your browser

Any scripts or data that you put into this service are public.

suncalc documentation built on Sept. 29, 2022, 5:11 p.m.