This function computes the geocentric position and velocity of an observer on the surface of the earth or on a near-earth spacecraft.

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

Syntax

C#
public short GeoPosVel(
	double JdTt,
	double DeltaT,
	Accuracy Accuracy,
	Observer Obs,
	ref double[] Pos,
	ref double[] Vel
)
Visual Basic
Public Function GeoPosVel ( _
	JdTt As Double, _
	DeltaT As Double, _
	Accuracy As Accuracy, _
	Obs As Observer, _
	ByRef Pos As Double(), _
	ByRef Vel As Double() _
) As Short
Visual C++
public:
virtual short GeoPosVel(
	double JdTt, 
	double DeltaT, 
	Accuracy Accuracy, 
	Observer Obs, 
	array<double>^% Pos, 
	array<double>^% Vel
) sealed

Parameters

JdTt
Type: System..::..Double
TT Julian date.
DeltaT
Type: System..::..Double
Value of Delta T (= TT - UT1) at 'JdTt'.
Accuracy
Type: ASCOM.Astrometry..::..Accuracy
Selection for accuracy
Obs
Type: ASCOM.Astrometry..::..Observer
Data specifying the location of the observer
Pos
Type: array<System..::..Double>[]()[][]%
Position vector of observer, with respect to origin at geocenter, referred to GCRS axes, components in AU.
Vel
Type: array<System..::..Double>[]()[][]%
Velocity vector of observer, with respect to origin at geocenter, referred to GCRS axes, components in AU/day.

Return Value

 0 ... everything OK
 1 ... invalid value of 'Accuracy'.
 

Remarks

The final vectors are expressed in the GCRS.

See Also