Evaluation of measurement data for an optical free-space aircraft to ground communication link system

by Vevek Selvaraj

Institution: Blekinge Institute of Technology
Year: 2014
Keywords: signalbehandling; signal processing; telekommunikation; telecommunications; optical free-space communication; power vectors; shack-hartmann wavefront sensors and finite state space markov model.
Record ID: 1352437
Full text PDF: http://www.bth.se/fou/cuppsats.nsf/6753b78eb2944e0ac1256608004f0535/f8e8e8d5f78fa0bec1257d70006b8165?OpenDocument


Optical free-space communication is an effective approach that can provide tap-proof, high bandwidth data communications. In this thesis there is an Optical link established between aircraft and the ground station. The link created between aircraft and ground station will go through the wavefront distortions due to the atmospheric turbulence,hence the signal quality is degraded. In order to optimise system performance the impact of atmospheric effects have to be evaluated for different light conditions and link distances. To compensate the wavefront distortions Adaptive Optics can be used. In this thesis the main aim is to process the measured data from different optical sensors in order to extract amplitude and phase information of the received field. The downlink data from the aircraft to the optical ground station that are obtained from Adaptive Optics as in this case Shack-Hartmann wavefront sensors in the ground station is analysed. The other part in the thesis is the analysis of the power vectors received during the data transmission from aircraft to the ground station. Finite State Space Markov Model is created for the analysis of the power vectors that are received with receivers of different aperture size.