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Proceedings Paper

Optical payload for lasercomm science (OPALS) link validation during operations from the ISS
Author(s): Abhijit Biswas; Bogdan Oaida; Kenneth S. Andrews; Joseph M. Kovalik; Matthew Abrahamson; Malcolm W. Wright
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Paper Abstract

In mid-2014 several day and nighttime links under diverse atmospheric conditions were completed using the Optical Payload for Lasercomm Science (OPALS) flight system on-board the International Space Station (ISS). In this paper we compare measured optical power and its variance at either end of the link with predictions that include atmospheric propagation models. For the 976 nm laser beacon mean power transmitted from the ground to the ISS the predicted mean irradiance of tens of microwatts per square meter close to zenith and its decrease with range and increased air mass shows good agreement with predictions. The irradiance fluctuations sampled at 100 Hz also follow the expected increase in scintillation with air mass representative of atmospheric coherence lengths at zenith at 500 nm in the 3-8 cm range. The downlink predicted power of hundreds of nanowatts was also reconciled within the uncertainty of the atmospheric losses. Expected link performance with uncoded bit-error rates less than 1E-4 required for the Reed- Solomon code to correct errors for video, text and file transmissions was verified. The results of predicted and measured powers and fluctuations suggest the need for further study and refinement.

Paper Details

Date Published: 16 March 2015
PDF: 10 pages
Proc. SPIE 9354, Free-Space Laser Communication and Atmospheric Propagation XXVII, 93540F (16 March 2015); doi: 10.1117/12.2084964
Show Author Affiliations
Abhijit Biswas, Jet Propulsion Lab. (United States)
Bogdan Oaida, Jet Propulsion Lab. (United States)
Kenneth S. Andrews, Jet Propulsion Lab. (United States)
Joseph M. Kovalik, Jet Propulsion Lab. (United States)
Matthew Abrahamson, Jet Propulsion Lab. (United States)
Malcolm W. Wright, Jet Propulsion Lab. (United States)

Published in SPIE Proceedings Vol. 9354:
Free-Space Laser Communication and Atmospheric Propagation XXVII
Hamid Hemmati; Don M. Boroson, Editor(s)

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