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/* Annual aberration - AA pages B17, B37, C24
*/
#include "kep.h"
extern double Clightaud;
int annuab( p )
double p[]; /* unit vector pointing from earth to object */
{
double A, B, C;
double betai, pV;
double x[3], V[3];
int i;
/* Calculate the velocity of the earth (see vearth.c).
*/
velearth( TDT );
betai = 0.0;
pV = 0.0;
for( i=0; i<3; i++ )
{
A = vearth[i]/Clightaud;
V[i] = A;
betai += A*A;
pV += p[i] * A;
}
/* Make the adjustment for aberration.
*/
betai = sqrt( 1.0 - betai );
C = 1.0 + pV;
A = betai/C;
B = (1.0 + pV/(1.0 + betai))/C;
for( i=0; i<3; i++ )
{
C = A * p[i] + B * V[i];
x[i] = C;
dp[i] = C - p[i];
}
showcor( "annual aberration", p, dp );
for( i=0; i<3; i++ )
p[i] = x[i];
return(0);
}
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