TheOrbit perturbationand orbit prediction orbiting status of a space target can be described by six orbital elementsOrbital elements, which can uniquely determine the orbit of the target, including the position, direction and shape of the orbit, namely the position and velocity of the target in orbit. The commonly used orbital elements are classical orbital elementsOrbital elements, which are represented by a, e, i, Ω, ω and υ. They constitute a group of vectors, which are called state vectors in generalized coordinates.