Precesses equatorial rectangular coordinates from one epoch to another.

Namespace: ASCOM.Astrometry.NOVAS
Assembly: ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: 6.0.0.0 (6.1.1.2619)

Syntax

C#
public short Precession(
	double JdTdb1,
	double[] Pos1,
	double JdTdb2,
	ref double[] Pos2
)
Visual Basic
Public Function Precession ( _
	JdTdb1 As Double, _
	Pos1 As Double(), _
	JdTdb2 As Double, _
	ByRef Pos2 As Double() _
) As Short
Visual C++
public:
virtual short Precession(
	double JdTdb1, 
	array<double>^ Pos1, 
	double JdTdb2, 
	array<double>^% Pos2
) sealed

Parameters

JdTdb1
Type: System..::..Double
TDB Julian date of first epoch. See remarks below.
Pos1
Type: array<System..::..Double>[]()[][]
Position vector, geocentric equatorial rectangular coordinates, referred to mean dynamical equator and equinox of first epoch.
JdTdb2
Type: System..::..Double
TDB Julian date of second epoch. See remarks below.
Pos2
Type: array<System..::..Double>[]()[][]%
Position vector, geocentric equatorial rectangular coordinates, referred to mean dynamical equator and equinox of second epoch.

Return Value

 0 ... everything OK
 1 ... Precession not to or from J2000.0; 'JdTdb1' or 'JdTdb2' not 2451545.0.
 

Remarks

One of the two epochs must be J2000.0. The coordinates are referred to the mean dynamical equator and equinox of the two respective epochs.

See Also