% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/generate_sky.R
\name{calculate_sun_brightness}
\alias{calculate_sun_brightness}
\title{Sample sun luminance at the disk center.}
\usage{
calculate_sun_brightness(
  elevation = 10,
  azimuth = 90,
  albedo = 0.5,
  turbidity = 3,
  altitude = 0,
  visibility = 50,
  hosek = TRUE,
  wide_spectrum = FALSE,
  lambda_nm = NULL
)
}
\arguments{
\item{elevation}{Default \code{10}. Solar elevation angle above/below
the horizon (degrees). Range \verb{[-4.2, 90]} for Prague, \verb{[0, 90]} for Hosek.}

\item{azimuth}{Default \code{90}. Solar azimuth (degrees).}

\item{albedo}{Default \code{0.5}. Ground albedo, range 0 to 1.}

\item{turbidity}{Default \code{3}. Atmospheric turbidity, range 1.7 to 10
(\emph{Hosek only}).}

\item{altitude}{Default \code{0}. Observer altitude (m), range 0 to 15000
(\emph{Prague only}).}

\item{visibility}{Default \code{50}. Meteorological range (km); \emph{Prague only}.}

\item{hosek}{Default \code{TRUE}. \code{FALSE} selects the Prague model.}

\item{wide_spectrum}{Default \code{FALSE}. Use wide-spectrum (55-channel)
coefficients for Prague at sea level only.}

\item{lambda_nm}{Optional vector of wavelengths for Hosek sampling.}
}
\value{
Numeric scalar of sun luminance (CIE Y, relative scale).
}
\description{
Evaluate the Prague or Hosek sky model at the sun center and
integrate against the CIE Y curve to return a luminance value. This is
useful for relative attenuation (e.g., comparing zenith sun to a low sun).
}
\examples{
calculate_sun_brightness(elevation = 45, hosek = TRUE)
}
