eclipticalToEquatorial: Convert ecliptical to equatorial coordinate

In oce: Analysis of Oceanographic Data

Convert ecliptical to equatorial coordinate

Description

Convert from ecliptical to equatorial coordinates, using equations 8.3 and 8.4 of reference 1, or, equivalently, equations 12.3 and 12.4 of reference 2.

Usage

eclipticalToEquatorial(lambda, beta, epsilon)

Arguments

lambda	longitude, in degrees, or a data frame containing lambda, beta, and epsilon, in which case the next to arguments are ignored
beta	geocentric latitude, in degrees
epsilon	obliquity of the ecliptic, in degrees

Details

The code is based on reference 1; see moonAngle() for comments on the differences in formulae found in reference 2. Indeed, reference 2 is only cited here in case readers want to check the ideas of the formulae; DK has found that reference 2 is available to him via his university library inter-library loan system, whereas he owns a copy of reference 1.

Value

A data frame containing columns rightAscension and declination both in degrees.

Author(s)

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(), equatorialToLocalHorizontal(), julianCenturyAnomaly(), julianDay(), moonAngle(), siderealTime(), sunAngle(), sunDeclinationRightAscension()

oce documentation built on July 9, 2023, 5:18 p.m.