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oce (version 1.8-3)

equatorialToLocalHorizontal: Convert Equatorial Coordinate to Local Horizontal Coordinate

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 reference 1, or, equivalently, from equations 12.5 and 12.6 of reference 2.

Usage

equatorialToLocalHorizontal(
  rightAscension,
  declination,
  t,
  longitude,
  latitude
)

Value

A data frame containing columns altitude (angle above horizon, in degrees) and azimuth (angle anticlockwise from south, in degrees).

Arguments

rightAscension

right ascension, e.g. calculated with eclipticalToEquatorial().

declination

declination, e.g. calculated with eclipticalToEquatorial().

t

time of observation.

longitude

longitude of observation, positive in eastern hemisphere.

latitude

latitude of observation, positive in northern hemisphere.

Author

Dan Kelley, based on formulae in references 1 and 2.

References

  • Meeus, Jean. Astronomical Formulas for Calculators. Second Edition. Richmond, Virginia, USA: Willmann-Bell, 1982.

  • Meeus, Jean. Astronomical Algorithms. Second Edition. Richmond, Virginia, USA: Willmann-Bell, 1991.

See Also

Other things related to astronomy: angle2hms(), eclipticalToEquatorial(), julianCenturyAnomaly(), julianDay(), moonAngle(), siderealTime(), sunAngle(), sunDeclinationRightAscension()