The perturbation effects on the collision warning for space object

For the problem of omitting dangerous time windows caused by perturbation factors while using analytical methods, the time prefilter algorithm was improved. In this method, the perturbation effect on first time window correction was introduced, and the effect of oblateness on the period of time window was considered. Take the space collision between two space objects in 2005 as an example, the perturbation effect on geometrical prefilter in the different time spans of interest was discussed, and the time windows that were calculated respectively by the time prefilter with no perturbation method, original method and improved method were compared. Results show that perturbation factor consideration can effectively reduce the risks of error screening dangerous targets due to chosen too small approach distance, and the time windows got from improved time prefilter algorithm is more complete and accurate.