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NOVAS31GravDef Method
Computes the total gravitational deflection of light for the observed object due to the major gravitating bodies in the solar system.

Namespace: ASCOM.Astrometry.NOVAS
Assembly: ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: 6.0.0.0 (6.3.0.2839)
Syntax
public short GravDef(
	double JdTdb,
	EarthDeflection LocCode,
	Accuracy Accuracy,
	double[] Pos1,
	double[] PosObs,
	ref double[] Pos2
)

Parameters

JdTdb
Type: SystemDouble
TDB Julian date of observation.
LocCode
Type: ASCOM.AstrometryEarthDeflection
Code for location of observer, determining whether the gravitational deflection due to the earth itself is applied.
Accuracy
Type: ASCOM.AstrometryAccuracy
Selection for accuracy
Pos1
Type: SystemDouble
Position vector of observed object, with respect to origin at observer (or the geocenter), referred to ICRS axes, components in AU.
PosObs
Type: SystemDouble
Position vector of observer (or the geocenter), with respect to origin at solar system barycenter, referred to ICRS axes, components in AU.
Pos2
Type: SystemDouble
Position vector of observed object, with respect to origin at observer (or the geocenter), referred to ICRS axes, corrected for gravitational deflection, components in AU.

Return Value

Type: Int16
    0 ... Everything OK
 < 30 ... Error from function 'Ephemeris'; 
 > 30 ... Error from function 'MakeObject'.
 
Remarks
This function valid for an observed body within the solar system as well as for a star.

If 'Accuracy' is set to zero (full accuracy), three bodies (Sun, Jupiter, and Saturn) are used in the calculation. If the reduced-accuracy option is set, only the Sun is used in the calculation. In both cases, if the observer is not at the geocenter, the deflection due to the Earth is included.

See Also