In many cases the new asteroid discoveries can then be used to identify other apparitions of the same object that were previously not recognized as being asteroids. That enables further orbit refinement.
> The THOR team has shown the potential to map out the trajectories of numerous asteroids in our neighborhood, but there are few key caveats. Since their images date from a few years ago, asteroids that haven’t been reobserved lately have effectively been lost at this point, although they could be picked up again in newer images down the road, says Paul Chodas, director of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory in Pasadena, California.