Application of Adaptive Optics to a Moon-to-Earth Optical Data Link

Abstract

The anticipated return to the Moon will require high bandwidth communications support for both manned and unmanned operations.

Mitigation of beam fluctuation due to atmospheric turbulence and prediction of control quality using intelligent decision-making tools

“…In recent years, FSO applications have generated much interest among the telecommunication community for both ground and space wireless link at high data rates. The FSO technology can be successfully used in various application scenarios, which include space communications, e.g., intersatellite and deep-space [10] and terrestrial communications, e.g., enterprise connectivity and backup links [11]. The optical communications through the atmosphere is important to commercial and defense applications [12].…”

“…The major limitations of FSO are line of sight maintenance for continuous data flow [3,16] and wavefront correction to significantly decrease the BER [1,2,7,19]. Therefore, a micromechanical autotracking, pointing acquisition and tracking (PAT) system, with beam steering controller design to mitigate the beam fluctuation [3,17,20] and an adaptive optics system to compensate the wavefront aberration, phase fluctuations [10,14,19], become significant to improve the link reliability and the data rate [1,2,11,21].…”

“…The beam fluctuation and deep signal fading (wavefront distortions) represent a unique and significantly more challenging problem [15], which cannot be resolved using conventional data coding techniques, and major incentive for incorporation of adaptive optics technology (beam steering and wavefront corrections) into FSOL is the active prevention of long-term data loss [1,10,14]. The first and most important approach in FSO is beam steering [8], which mitigates the beam fluctuation (temporal distortions) [3,11,12,16,22] and is the main contribution in this paper.…”

Large Area Carbon Nanotube Films

“…The high axial thermal conductivity has led to proposed applications including improved thermal contact between surfaces [1], heat pipes [2], and heat spreaders and heat sinks [3]. The high axial thermal conductivity has led to proposed applications including improved thermal contact between surfaces [1], heat pipes [2], and heat spreaders and heat sinks [3].…”

“…Electrical field emission properties [4] have led to applications in flat panel displays [5], xray electron sources [6], and beam line sources [7]. The exceptional tensile strength of carbon nanotubes has the potential for high strength-to-weight materials [3,12]. The exceptional tensile strength of carbon nanotubes has the potential for high strength-to-weight materials [3,12].…”