TITLE:
A Magnetically Levitated Precise Pointing Mechanism for Application to Optical Communication Terminals
AUTHORS:
Thomas Edward Donaldson Frame, Alexandre Alexandre Pechev
KEYWORDS:
Optical Communications; Magnetic Levitation; Control; Pointing; Active Anti-Vibration
JOURNAL NAME:
Optics and Photonics Journal,
Vol.2 No.2,
June
28,
2012
ABSTRACT: Increasing data bandwidth requirements from spacecraft systems is beginning to pressure existing microwave communications systems. Free-Space optical communications allows for larger bandwidths for lower relative power consumption, smaller size and weight when compared to the microwave equivalent. However optical communication does have a formidable challenge that needs to be overcome before the advantages of the technology can be fully utilized. In order for the communication to be successful the transmitter and receiver terminals need to be pointed with a high accuracy (generally in the order of ≤10 μradians) for the duration of communication. In this paper we present a new concept for the precise pointing of optical communications terminals (termed the Precise Pointing Mechanism). In this new concept we combine the separate pointing mechanisms of a conventional optical terminal into a single mechanism, reducing the complexity and cost of the optical bench. This is achieved by electromagnetically actuating the whole telescope assembly in 6 degrees-of-freedom with an angular resolution of less than ±3 μradians within a 10 (Az. El.) field of view and linear resolution of ±2 μm. This paper presents the new pointing mechanism and discusses the modelling, simulation and experimental work undertaken using the bespoke engineering model developed.