Refine Orbit

• Orbital refinement by perturbation is a critical function implemented within Asteroid PRO. The process typically is automatically applied to occultation searches and functions that plot or output the shadow path where extreme accuracy is required. When not automatically applied, Asteroid PRO informs the user that they are about to perform a calculation or display using an orbit the epoch of which differs significantly from the selected date of the desired operation.

• The Refine Orbit function offers the user full control of the perturbation process. This is useful in cases where the date of a potential occultation lies outside of the range of Asteroid PRO to apply its automatic, high speed perturbation methods to successfully find the occultation. In this case, the user can manually perturb the orbit to the desired date, set the star coordinates into a UOB, and watch the occultation by positioning the asteroid to the selected date.

• Another use of this Refine Orbit Screen is to gain educational insight to the perturbation process by viewing the relative gravitational effects of the planets (and large asteroids) as the orbit is integrated from one epoch to another. On the left of the screen is a dynamic display showing the changing distances from the planets to the asteroid and the relative gravitational accelerations produced by each of the planets. At the conclusion of the integration, on the right of the screen, the rectangular coordinates, position and velocity, of the orbit are shown, for the asteroid and each of the planets.

• Another educational feature is the provision to select which planets and asteroids to include as perturbers. For example, one can immediately see the effects on an orbit with and without Jupiter or any combination of perturbing bodies.

• Finally, upon exit from the Refine Orbit Screen, a summary screen is displayed showing the changes in each of the elements from one epoch to the next. The user then can choose to [Save] the new Refined orbit or exit, [No Save], without updating the Refined orbit.