LaunchVehicle: Sun Vector

The apparent position of the Sun with respect to the object, 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. The apparent position can be requested in a variety of coordinate systems. 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.

Type: Time-varying data

Availability: Reports | Graphs | Dynamic Displays | Strip Charts

Name Description
Fixed A coordinate system attached to the central body and rotating with it. The z-axis is nominally along the rotation axis.
ICRF Earth's attitude expressed with respect to the ICRF frame.
MeanOfDate The mean equator mean equinox coordinate system evaluated at the requested time.
MeanOfEpoch The mean equator mean equinox coordinate system evaluated at the epoch of the object.
TrueOfDate The true equator true equinox coordinate system evaluated at the requested time.
TrueOfEpoch The true equator true equinox coordinate system evaluated at the epoch of the object.
B1950 The 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).
TEMEOfEpoch The true equator mean equinox coordinate system evaluated at the epoch of the object.
TEMEOfDate The true equator mean equinox coordinate system evaluated at the requested time.
AlignmentAtEpoch The non-rotating coordinate system coincident with the Fixed system evaluated at the object's coordinate reference epoch.
J2000 The mean equator mean equinox coordinate system evaluated at the J2000.0 epoch (2000 January 1.5 = JD 2451545.0 TDB).

STK Programming Interface 11.0.1