Data Provider Groups | Data Provider Elements

CB Inertial To Fixed Quaternions

Orientation of central body fixed coordinate axes.

Available for these objects: Scenario

Type: Time-varying data.

Availability: Reports | Graphs | Dynamic Displays | Strip Charts

Data Provider Groups

Data can be requested relative to a variety of inertial coordinate axes. The available coordinate axes depend on the scenario's central body. Nominally, the axes 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.

Name	Description
ICRF	International 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).
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 nonrotating 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 TDB = JD 2451545.0 TDB).

Data Provider Elements

Name	Dimension	Type	Description
Time	Date	Real Number or Text	Time.
q1	Unitless	Real Number	First element of quaternion (and of its vector part) representing the orientation between the two sets of axes.
q2	Unitless	Real Number	Second element of quaternion (and of its vector part) representing the orientation between the two sets of axes.
q3	Unitless	Real Number	Third element of quaternion (and of its vector part) representing the orientation between the two sets of axes.
q4	Unitless	Real Number	Fourth element of quaternion (its scalar part) representing the orientation between the two sets of axes.