Data Providers: LaunchVehicle: Ephemeris Diff: TrueOfEpoch

LaunchVehicle: Ephemeris Diff: TrueOfEpoch

The true equator true equinox coordinate system evaluated at the epoch of the object.

Name	Dimension	Type	Description
Time	DateFormat	Real Number	Time.
x	DistanceUnit	Real Number	The X component of the position vector.
y	DistanceUnit	Real Number	The Y component of the position vector.
z	DistanceUnit	Real Number	The Z component of the position vector.
vx	Rate	Real Number	X Cartesian component of velocity.
vy	Rate	Real Number	Y Cartesian component of velocity.
vz	Rate	Real Number	Z Cartesian component of velocity.
Range	DistanceUnit	Real Number	The range (i.e., distance between the primary and secondary object) at the given time.
Range Rate	Rate	Real Number	The rate of change of the magnitude of the relative position vector. This is computed using the analytical formula dot_product(relative_position_vector, relative_velocity_vector) / magnitude(relative_position_vector). This is an exact formula when the velocity is the derivative of position. Some propagators (e.g., SGP4, J2Perturbation, J4Perturbation), however, produce ephemerides where the velocity is not exactly the derivative of position so that this formula does not compute the derivative of range exactly in such cases.
Speed	Rate	Real Number	Magnitude of the velocity vector of the projection of the selected point onto the reference plane.
Approach Angle	AngleUnit	Real Number	The angle between the inertial velocity of the primary object and the inertial velocity of the secondary object at the given time
Miss Distance	DistanceUnit	Real Number	The component of the relative position vector perpendicular to the relative velocity vector.
Position Combined Cov Sigma	Unitless	Real Number	Position difference measured in terms of the combined position covariance of primary and target satellites. Reports N where the current relative position vector lies on an N sigma ellipsoid, where the ellipsoid is obtained from the sum of the covariances matrices of the two objects. This can only be computed if position covariance is available.
Position Cov Sigma	Unitless	Real Number	Position difference measured in terms of the position covariance. Reports N where the current relative position vector lies on a N sigma ellipsoid, where the ellipsoid if obtained from the position covariance of the primary satellite. This can only be computed if position covariance is available.