Orbital state vectors
In astrodynamics and celestial dynamics, the orbital state vectors (sometimes state vectors) of an orbit are Cartesian vectors of position ( r {\displaystyle \mathbf {r} } ) and velocity ( v {\displaystyle \mathbf {v} } ) that together with their time (epoch) ( t {\displaystyle t} ) uniquely determine the trajectory of the orbiting body in space. Orbital state vectors come in many forms including the traditional Position-Velocity vectors, Two-line element set (TLE), and Vector Covariance Matrix (VCM).