computeSolarToLocalTimeDifference: computeSolarToLocalTimeDifference

In solartime: Utilities Dealing with Solar Time Such as Sun Position and Time of Sunrise

Description

computes the time difference in hours between (apparent) solar time and local time

Usage

computeSolarToLocalTimeDifference(longDeg, 
    timeZone, doy = NA, fracYearInRad = 2 * 
        pi * (doy - 1)/365.24)

Arguments

longDeg	Longitude in (decimal) degrees
timeZone	Time zone (in hours) ahead of UTC (Berlin is +1)
doy	integer vector with day of year [DoY, 1..366], Specify NA get mean solar time across the year instead of apparent solar time (i.e. with differences throughout the year due to eccentricity of earth orbit)
fracYearInRad	may specify instead of doy for efficiency.

Value

time difference in hours to be added to local winter time to get solar time

Author(s)

Thomas Wutzler

Examples

# Jena: 50.927222, 11.586111
longDeg <- 11.586
doi <- 1:366
# due to longitude: west of timezone meridian: sun culminates later,
# solar time is less than local time
(localDiff <- computeSolarToLocalTimeDifference(longDeg, 1L)*60)
# taking into account shift during the year due to earth orbit eccentricity
plot( computeSolarToLocalTimeDifference(longDeg, 1L, doi)*60 ~ doi )
abline(h = localDiff)

Example output

[1] -13.656

solartime documentation built on April 22, 2021, 5:10 p.m.