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NOVAS31State Method

Read and interpolate the JPL planetary ephemeris file.

Namespace:  ASCOM.Astrometry.NOVAS
Assembly:  ASCOM.Astrometry (in ASCOM.Astrometry.dll) Version: 3c9121baba46811fe6e53a58a05935662261416d
public short State(
	ref double[] Jed,
	Target Target,
	ref double[] TargetPos,
	ref double[] TargetVel


Type: SystemDouble
2-element Julian date (TDB) at which interpolation is wanted. Any combination of jed[0]+jed[1] which falls within the time span on the file is a permissible epoch. See Note 1 below.
Type: ASCOM.AstrometryTarget
The requested body to get data for from the ephemeris file.
Type: SystemDouble
The barycentric position vector array of the requested object, in AU. (If target object is the Moon, then the vector is geocentric.)
Type: SystemDouble
The barycentric velocity vector array of the requested object, in AU/Day.

Return Value

Type: Int16
 0 ...everything OK
 1 ...error reading ephemeris file
 2 ...epoch out of range.
The target number designation of the astronomical bodies is:
         = 0: Mercury,               1: Venus, 
         = 2: Earth-Moon barycenter, 3: Mars, 
         = 4: Jupiter,               5: Saturn, 
         = 6: Uranus,                7: Neptune, 
         = 8: Pluto,                 9: geocentric Moon, 
         =10: Sun.

NOTE 1. For ease in programming, the user may put the entire epoch in jed[0] and set jed[1] = 0. For maximum interpolation accuracy, set jed[0] = the most recent midnight at or before interpolation epoch, and set jed[1] = fractional part of a day elapsed between jed[0] and epoch. As an alternative, it may prove convenient to set jed[0] = some fixed epoch, such as start of the integration and jed[1] = elapsed interval between then and epoch.

See Also