StarGetEarth Method

Obtains the barycentric and heliocentric positions and velocities of the Earth from the solar system ephemeris.

Definition

Namespace: ASCOM.Tools.NovasCom
Assembly: ASCOM.AstrometryTools (in ASCOM.AstrometryTools.dll) Version: 3.0.0-rc.1+86c25ce733aebb4d8b1b8a62e84770ea5e972bea

C#

public short GetEarth(
	double tjd,
	Body earth,
	ref double tdb,
	ref double[] bary_earthp,
	ref double[] bary_earthv,
	ref double[] helio_earthp,
	ref double[] helio_earthv
)

VB

Public Function GetEarth ( 
	tjd As Double,
	earth As Body,
	ByRef tdb As Double,
	ByRef bary_earthp As Double(),
	ByRef bary_earthv As Double(),
	ByRef helio_earthp As Double(),
	ByRef helio_earthv As Double()
) As Short

Parameters

tjd Double: Terrestrial Julian date
earth Body: Earth body structure
tdb Double: Dynamic barycentric time corresponding to the provided Julian date.
bary_earthp Double: Barycentric position vector of Earth at 'tjd'; equatorial rectangular coordinates in AU referred to the mean equator and equinox of J2000.0.
bary_earthv Double: Barycentric velocity vector of Earth at 'tjd'; equatorial rectangular system referred to the mean equator and equinox of J2000.0, in AU/Day.
helio_earthp Double: Heliocentric position vector of Earth at 'tjd'; equatorial rectangular coordinates in AU referred to the mean equator and equinox of J2000.0.
helio_earthv Double: Heliocentric velocity vector of Earth at 'tjd'; equatorial rectangular system referred to the mean equator and equinox of J2000.0, in AU/Day.

Return Value

Int16
0...Everything OK or >0...Error code from function 'solarsystem'.

Remarks

PURPOSE: Obtains the barycentric and heliocentric positions and velocities of the Earth from the solar system ephemeris. REFERENCES: None. INPUT ARGUMENTS: tjd (double) TT (or TDT) Julian date. *earth (struct body) Pointer to structure containing the body designation for the Earth (defined in novas.h). OUTPUT ARGUMENTS: *tdb (double) TDB Julian date corresponding to 'tjd'. *bary_earthp (double) Barycentric position vector of Earth at 'tjd'; equatorial rectangular coordinates in AU referred to the mean equator and equinox of J2000.0. *bary_earthv (double) Barycentric velocity vector of Earth at 'tjd'; equatorial rectangular system referred to the mean equator and equinox of J2000.0, in AU/Day. *helio_earthp (double) Heliocentric position vector of Earth at 'tjd'; equatorial rectangular coordinates in AU referred to the mean equator and equinox of J2000.0. *helio_earthv (double) Heliocentric velocity vector of Earth at 'tjd'; equatorial rectangular system referred to the mean equator and equinox of J2000.0, in AU/Day. RETURNED VALUE: (short int) 0...Everything OK. >0...Error code from function 'solarsystem'. GLOBALS USED: BARYC, HELIOC FUNCTIONS CALLED: tdb2tdt novas.c solarsystem (user's choice) fabs math.h VER./DATE/ PROGRAMMER: V1.0/10-95/WTH (USNO/AA) V1.1/06-97/JAB (USNO/AA): Incorporate 'body' structure in input. NOTES: None.

Version Information

.NET Standard

Supported in: 2.0