diurnal_ab.c File Reference

Correct for diurnal aberration. More...

#include <math.h>
#include <stdlib.h>
#include "aephem.h"

Functions
void	ae_diurnal_aberration (double last, double tlat, double trho, int direction, double *ra, double *dec)
	Correct for diurnal aberration. More...

Detailed Description

Correct for diurnal aberration.

Function Documentation

void ae_diurnal_aberration	(	double	last,
		double	tlat,
		double	trho,
		int	direction,
		double *	ra,
		double *	dec
	)

Correct for diurnal aberration.

This formula is less rigorous than the method used for annual aberration (see ae_annual_aberration()). However, the correction is small.

Parameters

last	The local apparent sidereal time, in degrees.
tlat	The geocentric latitude of the observer, in degrees.
trho	The distance from the centre of the earth to the observer, in earth radii.
direction	To add aberration to p, pass AE_ADD_ABERRATION; to remove it, pass AE_REMOVE_ABERRATION; if neither is passed, then AE_REMOVE_ABERRATION is assumed. AE_ADD_ABERRATION is appropriate, for example, if one wishes to compute the apparent position of a star from a catalogue position, while AE_REMOVE_ABERRATION is appropriate, for example, if one wants to compute the true position of an observed star.
ra	The right ascension of the object, in degrees; this routine modifies this parameter to correct for diurnal aberration.
dec	The declination of the object, in degrees; this routine modifies this parameter to correct for diurnal aberration.

References AE_ADD_ABERRATION, AE_DTR, and AE_RTD.

Referenced by ae_topocentric().