Decision Support in Space Situational Awareness
Richard I. Abbot, Timothy P. Wallace · 2007
n To maintain the space catalog, the sensors of Air Force Space Command routinely track over 10,000 orbiting space objects. Because of the limited number of sensors, however, we cannot maintain persistent surveillance on these objects. This article describes algorithms and systems developed by Lincoln Laboratory to provide commercial and military analysts with better space situational awareness and decision support as they address problems in the space arena. The first problem is collision avoidance in the increasingly crowded geosynchronous earth orbit (GEO) belt, where there is continuous potential for on-orbit collisions between active satellites and debris, dead satellites, or other active payloads. This case is known as cooperative monitoring, since the owners of the satellites of concern share their operating data. Another problem is noncooperative GEO satellite monitoring, in which space analysts have no information about the satellite station keeping and maneuver plans. In this case, space surveillance data provide the only method to determine orbital status. This article summarizes GEO satellite orbits and their control, and describes a cooperative monitoring system for assisting satellite operators in maintaining safe spacing to nearby objects. We also address the noncooperative GEO monitoring problem by using Bayesian networks to combine signature and metric information from space surveillance sensors, which allows us to detect satellite status changes and produce automated alerts.