Data Provider Groups | Data Provider Elements

Sun Vector

The apparent position of the Sun with respect to the object as observed from the requested coordinate system, expressed in Cartesian components, as a function of time.

The light time delay is actually computed between the Sun and the object's central body, rather than directly from the object itself.



Available for these objects: Aircraft, GroundVehicle, LaunchVehicle, Missile, Satellite, Ship

Type: Time-varying data.

Availability: Reports | Graphs | Dynamic Displays | Strip Charts

Data Provider Groups

Data can be requested in a variety of coordinate systems, where the origin of the coordinate system is the object's central body. The available coordinate systems depend on the object's central body. Nominally, the systems Fixed, Inertial, J2000, TrueOfDate, and MeanOfDate are supported, although some central bodies (notably the Earth and Sun) have more.

The following lists the systems available for Earth.
NameDescription
TrueOfDateRotatingA variation of the Fixed system where pole wander is ignored. The equator is the same as the TrueOfDate equator and the frame spins about the TrueOfDate z-axis.
FixedA coordinate system attached to the central body and rotating with it. The z-axis is nominally along the rotation axis.
ICRFInternational Celestial Reference Frame. The ICRF axes are defined as the inertial (i.e., kinematically non-rotating) axes associated with a general relativity frame centered at the solar system barycenter (often called the BCRF).
MeanOfDateThe mean equator mean equinox coordinate system evaluated at the requested time.
MeanOfEpochThe mean equator mean equinox coordinate system evaluated at the epoch of the object.
TrueOfDateThe true equator true equinox coordinate system evaluated at the requested time.
TrueOfEpochThe true equator true equinox coordinate system evaluated at the epoch of the object.
B1950The mean equator mean equinox coordinate system evaluated at the beginning of the Besselian year 1950 (31 December 1949 22:09:46.866 = JD 2433282.4234591).
TEMEOfEpochThe true equator mean equinox coordinate system evaluated at the epoch of the object.
TEMEOfDateThe true equator mean equinox coordinate system evaluated at the requested time.
AlignmentAtEpochThe nonrotating coordinate system coincident with the Fixed system evaluated at the object's coordinate reference epoch.
J2000The mean equator mean equinox coordinate system evaluated at the J2000.0 epoch (2000 January 1.5 TDB = JD 2451545.0 TDB).

Data Provider Elements

NameDimensionTypeDescription
TimeDateReal Number or TextTime.
xDistanceReal NumberThe X component of the position vector.
yDistanceReal NumberThe Y component of the position vector.
zDistanceReal NumberThe Z component of the position vector.