The position and velocity of the object, expressed in equinoctial elements, as a function of time in the requested coordinate system. Equinoctial elements are a set of orbital elements that are not singular when the eccentricity becomes zero or the orbit is equatorial. Rates of the elements may also be reported. Rates are computed using variation of parameters expressions with the perturbative acceleration which is computed as the total acceleration minus the two body acceleration, expressed in the requested coordinate system. Due to the method of computation, element rates will not be consistent with finite differencing of the element values for cases where the velocity is not the true time derivitive of the acceleration; for this reason, these values will not be reported for the J2, J4 and SGP4 propagators. The elements can be requested in a variety of coordinate systems. The available coordinate systems depend on the object's central body. Nominally, the systems Inertial, J2000, TrueOfDate, and MeanOfDate are supported, although some central bodies (notably the Earth and Sun) have more. The following lists the inertial systems available for Earth.