equatorialToLocalHorizontal.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/moon.R
\name{equatorialToLocalHorizontal}
\alias{equatorialToLocalHorizontal}
\title{Convert equatorial to local horizontal coordinate}
\usage{
equatorialToLocalHorizontal(rightAscension, declination, t, longitude, latitude)
}
\arguments{
\item{rightAscension}{right ascension, e.g. calculated with
\code{\link{eclipticalToEquatorial}}.}

\item{declination}{declination, e.g. calculated with
\code{\link{eclipticalToEquatorial}}.}

\item{t}{time of observation.}

\item{longitude}{longitude of observation, positive in eastern hemisphere.}

\item{latitude}{latitude of observation, positive in northern hemisphere.}
}
\value{
A data frame containing columns \code{altitude} (angle above
horizon, in degrees) and \code{azimuth} (angle anticlockwise from south, in
degrees).
}
\description{
Convert from equatorial coordinates to local horizontal coordinates, i.e.
azimuth and altitude.
The method is taken from equations 8.5 and 8.6 of [1], or, equivalently,
from equations 12.5 and 12.6 of [2].
}
\author{
Dan Kelley, based on formulae in [1] and [2].
}
\references{
1. Meeus, Jean, 1982. Astronomical formulae for Calculators.
Willmann-Bell. Richmond VA, USA. 201 pages.

2. Meeus, Jean, 1991. Astronomical algorithms.  Willmann-Bell, Richmond VA,
USA. 429 pages.
}
\seealso{
Other things related to astronomy: \code{\link{eclipticalToEquatorial}},
  \code{\link{julianCenturyAnomaly}},
  \code{\link{julianDay}}, \code{\link{moonAngle}},
  \code{\link{siderealTime}}, \code{\link{sunAngle}}
}