fk4_to_fk5.c File Reference

Convert FK4 B1950.0 catalogue coordinates to FK5 J2000.0 coordinates. More...

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

Functions
void	ae_fk4_to_fk5 (struct ae_star_t *el)
	Convert FK4 B1950.0 catalogue coordinates to FK5 J2000.0 coordinates. More...

Variables
double	ae_fk4_to_fk5_abb [3] = {-1.62557e-6, -3.1919e-7, - 1.3843e-7}
	Factors to eliminate E terms of aberration in FK4 to FK5 conversion.
double	ae_fk4_to_fk5_abb_d [3] = {1.244e-3, -1.579e-3, -6.60e-4}
	Factors to eliminate E terms of aberration in FK4 to FK5 conversion.
double	ae_fk4_to_fk5_mat [36]
	Tranformation matrix for FK4 to FK5 conversion. More...

Detailed Description

Convert FK4 B1950.0 catalogue coordinates to FK5 J2000.0 coordinates.

Function Documentation

void ae_fk4_to_fk5

(

struct ae_star_t *

el

)

Convert FK4 B1950.0 catalogue coordinates to FK5 J2000.0 coordinates.

See AA page B58.

Parameters

el	The catalogue object to update to J2000.0.

References AE_DTR, ae_fk4_to_fk5_abb, ae_fk4_to_fk5_abb_d, ae_fk4_to_fk5_mat, AE_J2000, AE_RTD, ae_zatan2(), ae_star_t::dec, ae_star_t::epoch, ae_star_t::mudec, ae_star_t::mura, ae_star_t::px, ae_star_t::ra, and ae_star_t::v.

Referenced by ae_geocentric_from_cat().

Variable Documentation

double ae_fk4_to_fk5_mat[36]

Initial value:

= {
  0.9999256782,  -0.0111820611,  -4.8579477e-3,
  2.42395018e-6, -2.710663e-8,   -1.177656e-8,
  0.0111820610,  0.9999374784,   -2.71765e-5,
  2.710663e-8,   2.42397878e-6,  -6.587e-11,
  4.8579479e-3,  -2.71474e-5,    0.9999881997,
  1.177656e-8,   -6.582e-11,     2.42410173e-6,
  -5.51e-4,      -0.238565,      0.435739,
  0.99994704,    -0.01118251,    -4.85767e-3,
  0.238514,      -2.667e-3,      -8.541e-3,
  0.01118251,    0.99995883,     -2.718e-5,
  -0.435623,     0.012254,       2.117e-3,
  4.85767e-3,    -2.714e-5,      1.00000956
}

Tranformation matrix for FK4 to FK5 conversion.

Transformation matrix for unit direction vector, and motion vector in seconds of arc per century.

Referenced by ae_fk4_to_fk5().