get_DayTimeLimits {RchivalTag}

Estimating the timing of sunrise, sunset, astronomical and nautical twilight events

Description

Estimating the timing of sunrise, sunset, astronomical and nautical twilight events in POSIXct-format based on geolocations and a similar time vector. The function is a simplified call of the sunriset and crepuscule functions of the maptools-package that are based on algorithms provided by the National Oceanic & Atmospheric Administration (NOAA).

Usage

get_DayTimeLimits(pos)

Arguments

pos

a data.frame with the columns datetime (a time vector in POSIXct-format), Lon and Lat.

Value

The input data.frame pos extended by the time vectors sunrise, sunset, dawn.naut, dawn.ast, dusk.naut and dusk.ast.

Author(s)

Robert K. Bauer

References

Meeus, J. (1991) Astronomical Algorithms. Willmann-Bell, Inc.

See Also

sunriset, crepuscule, classify_DayTime

Examples

#### example 1) estimate current times of dawn, sunrise, dusk and sunset in Mainz, Germany:
pos <- data.frame(Lat=8.2667, Lon=50)
pos$datetime <- strptime(Sys.Date(),"%Y-%m-%d")
get_DayTimeLimits(pos)

#### example 1b) classify current ime of the day in Mainz, Germany:
classify_DayTime(get_DayTimeLimits(pos))