Active Vibration Control for Enhanced Satellite Communications

ABSTRACT: As the data rates of satellite communication links increase due to inclusion of high resolution imagery and video, a high bandwidth backbone network is required to support all uses of the network. Free-Space Optical (FSO) communication links have the ability to provide very high data rates over very long propagation distances, however, due to their narrow beam divergence, they require accurate pointing and tracking of the terminal apertures. To address this need, SA Photonics proposes the AccuPoint Beam Control System. The AccuPoint system utilizes a compact Optical Inertial Reference Unit (OIRU) to generate an inertially stabilized Optical Reference Beam (ORB) that traverses the entire optical path, picking up jitter errors along the way. SA Photonics"proprietary high bandwidth control system measures the induced jitter which is removed from both the incoming and outgoing FSO optical beams. A closed-loop control bandwidth in excess of 1 kHz provides jitter attenuation up to 100s of Hz. The OIRU utilizes highly accurate Fiber-Optic Gyroscope (FOG) based angular rate sensors which provide angular rate sensitivity down to DC. Therefore, signals from the IRU can be used during acquisition when absolute pointing accuracy is required while the aperture scans it"s transmit beam and searches for received optical power. BENEFIT: The AccuPoint system enables long distance FSO links by performing active stabilization of optical apertures. The AccuPoint system has very small SWaP allowing use in a variety of platforms, and is designed from the ground up for the space environment, ensuring robust and reliable operation.