Autonomous scan management (ASM) for Earth sensors

This paper describes the Autonomous Sensor Management (ASM) monitor used to manage the Earth Sensor Assembly (ESA) configurations of 26 satellites spread across five different series. It applies to geosynchronous satellites that use a scanning ESA as the primary sensor for attitude control. After an initial setup of each satellite, ASM compares the ephemeris data for each satellite with the ephemeris data for the Sun and Moon and determines when a second target could interfere with the ESA Field of View (FOV). When interference is predicted, ASM schedules the commands to properly configure the ESA. ASM then monitors the satellite telemetry data to verify the ESA is in the proper state. If the ESA is not in the proper state as the interference time approaches, ASM will alarm the satellite controllers to correct the problem. The system has performed flawlessly for several years, saving INTELSAT numerous man-hours and reducing the risks to satellite availability due to operator error. INTELSAT owns and operates a global communications satellite system providing capacity for voice, video, corporate/private networks and Internet in more than 200 countries and territories