solaR2 (version 0.11)

C_solarAngles: Solar angles

Description

A set of functions that compute the apparent movement of the Sun from the Earth.

Usage

## Declination
declination(d, method = 'michalsky')
## Eccentricity
eccentricity(d, method = 'michalsky')
## Equation of time
eot(d)
## Solar time
sunrise(d, lat, method = 'michalsky',
        decl = declination(d, method = method))

## Extraterrestrial irradiation
bo0d(d, lat, method = 'michalsky',
     decl = declination(d, method = method),
     eo = eccentricity(d, method = method),
     ws = sunrise(d, lat, method = method))
## Sun hour angle
sunHour(d, BTi, sample = 'hour', EoT = TRUE,
        method = 'michalsky',
        eqtime = eot(d))
## Cosine of the zenith angle
zenith(d, lat, BTi, sample = 'hour', method = 'michalsky',
       decl = declination(d, method = method),
       w = sunHour(d, BTi, sample, method = method))
## Azimuth angle
azimuth(d, lat, BTi, sample = 'hour', method = 'michalsky',
        decl = declination(d, method = method),
        w = sunHour(d, BTi, sample, method = method),
        cosThzS = zenith(d, lat, BTi, sample,
                         method = method,
                         decl = decl,
                         w = w))

Value

A vector with the calculated elements. Its size varies depending on whether the calculations are daily or intradaily.

Arguments

d

Date, a daily time base, it may be the result of fBTd

method

character, method for the sun geometry calculations, to be chosen from 'cooper', 'spencer', 'michalsky' and 'strous'. See references for details.

lat

numeric, latitude (degrees) of the point of the Earth where calculations are needed. It is positive for locations above the Equator.

sample

Character, increment of the intradaily sequence.

BTi

POSIXct, intradily time base, it may the result of fBTi.

EoT

logical, if EoT=TRUE (default value), the function sunHour use the Equation of time

decl, eo, ws, eqtime, w, cosThzS

Arguments that compute the variables they reference (default value). It can be replaced with previously calculated values to avoid calculating the same variable twice.

Author

Francisco Delgado López, Oscar Perpiñán Lamigueiro.

References

• Cooper, P.I., Solar Energy, 12, 3 (1969). "The Absorption of Solar Radiation in Solar Stills"

• Spencer, Search 2 (5), 172, https://www.mail-archive.com/[e-mail]/msg01050.html

• Strous: https://www.aa.quae.nl/en/reken/zonpositie.html

• Michalsky, J., 1988: The Astronomical Almanac's algorithm for approximate solar position (1950-2050), Solar Energy 40, 227-235

• Perpiñán, O, Energía Solar Fotovoltaica, 2015. (https://oscarperpinan.github.io/esf/)

• Perpiñán, O. (2012), "solaR: Solar Radiation and Photovoltaic Systems with R", Journal of Statistical Software, 50(9), 1-32, tools:::Rd_expr_doi("10.18637/jss.v050.i09")

See Also

fSolD, fSolI, calcSol

Examples

library("data.table")
setDTthreads(2)

d = fBTd(mode = 'serie')[100]

decl = declination(d, method = 'michalsky')
decl

w = sunHour(d, sample = 'hour', method = 'michalsky')
w

cosThzS = zenith(d, lat = 37.2, sample = 'hour',
                 method = 'michalsky',
                 decl = decl,
                 w = w)
cosThzS