Numerical planetary and lunar ephemerides - Present status, precision and accuracies

Features of the emphemeris creation process are described with attention given to the equations of motion, the numerical integration, and the least-squares fitting process. Observational data are presented and ephemeride accuracies are estimated. It is believed that radio measurements, VLBI, occultations, and the Space Telescope and Hipparcos will improve ephemerides in the near future. Limitations to accuracy are considered as well as relativity features. The export procedure, by which an outside user may obtain and use the JPL ephemerides, is discussed.