CAARiseTransitSet_Calculate: CAARiseTransitSet_Calculate

In helixcn/skycalc: Computational Astronomy in R based on PJ Naughter's AA+ library

Description

CAARiseTransitSet_Calculate

Usage

CAARiseTransitSet_Calculate(JD, Alpha1, Delta1, Alpha2, Delta2, Alpha3, Delta3, Longitude, Latitude, h0)

Arguments

JD	JD The Julian Day corresponding to that midnight Dynamical Time for the date when you want to perform the calculation.
Alpha1	Alpha1 The right ascension in hours of the object at time JD - 1 day
Delta1	Delta1 The declination in degrees of the object at time JD - 1 day
Alpha2	Alpha2 The right ascension in hours of the object at time JD
Delta2	Delta2 The declination in degrees of the object at time JD
Alpha3	Alpha3 The right ascension in hours of the object at time JD + 1 day
Delta3	Delta3 The declination in degrees of the object at time JD + 1 day
Longitude	Longitude The geographic longitude of the observer in degrees.
Latitude	Latitude The geographic latitude of the observer in degrees.
h0	h0 The "standard" altitude in degrees i.e. the geometric altitude of the centre of the body at the time of the apparent rising or setting. For stars and planets, you would normally use -0.5667, for the Sun you would use -0.8333 and for the moon you would use 0.7275 * PI - 0.5666 where PI is the Moon's horizontal parallax in degrees (If no great accuracy is required, the mean value of h0 = 0.125 can be used).

Note

Ensure the RA values are corrected for interpolation. Due to important Remark 2 by Meeus on Interopolation of RA values

Author(s)

C++ code by PJ Naughter, imported to R by Jinlong Zhang

References

Meeus, J. H. (1991). Astronomical algorithms. Willmann-Bell, Incorporated.

Examples

CAARiseTransitSet_Calculate(JD = 2456597.5, Alpha1 = 123.1, Delta1 = 22.1 , 
Alpha2 = 124.2, Delta2 = 22.2, Alpha3 = 124.9, Delta3 = 22.3, 
Longitude = 117.20, Latitude = 46.45, h0 = 0.5667)

helixcn/skycalc documentation built on March 31, 2021, 5:45 a.m.