The enclosed Pascal source code implements the NORAD SGP4/SDP4 orbital models for use with the standard two-line orbital element sets to determine earth- centered inertial (ECI) and topocentric coordinates of earth-orbiting objects. This code implements both the near-earth and deep-space portions of the NORAD SGP4 orbital model. These units are designed to make the development of programs based on the NORAD orbital models straightforward and standardized
