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photobiology (version 0.11.3)

calendar_change: Solar astronomy using Meeus' algorithm

Description

The exact julian day computation is adapted from ode::julianDay() and tested againts test cases in Redas and Andreas (2008, table A4.1) for validity up to year 4712 BC.

Usage

calendar_change

julian_day(time)

julian_day_fast(time)

julian_century(time)

geom_mean_lon_sun(x)

geom_mean_anom_sun(x)

eccent_earth_orbit(x)

sun_eq_of_ctr(x, anom)

sun_rad_vector(eccent, anom)

sun_app_lon(x, lon)

mean_obliq_eclip(x)

obliq_corr(x, eclip)

sun_rt_ascen(app.lon, obliq.corr)

sun_decline(app.lon, obliq.corr)

var_y(obliq.corr)

eq_of_time(mean.lon, eccent.earth, anom.mean, var.y)

ha_sunrise(lat, decline, nag = 0)

solar_noon(lon, eq.of.time)

sunrise(noon, ha.sunrise)

sunset(noon, ha.sunrise)

sunlight_duration(ha.sunrise, unit.out = "hours")

solar_datetime(time, lat, lon, eq.of.time)

solar_tod(time, lat, lon, eq.of.time)

hour_angle(solar.time)

zenith_angle(lat, hour.angle, decline)

elevation_angle(lat, hour.angle, decline)

atm_refraction_approx(elevation.angle)

azimuth_angle(lat, hour.angle, zenith.angle, decline)

Value

datetime

numeric

Format

An object of class POSIXct (inherits from POSIXt) of length 1.

Arguments

time

dateTime

x

numeric Julian century

anom

numeric Solar anomaly in degrees

eccent

numeric Eccentricity of Earth orbit

eclip

numeric Ecliptic

app.lon, obliq.corr, mean.lon, nag, decline

numeric Angles in degrees

lat, lon

numeric Geographic coordinates in degrees

eq.of.time, ha.sunrise, noon

numeric

zenith.angle, elevation.angle, hour.angle

numeric Angles in degrees

Details

Low level functions based on NOAA's Excel worksheet