Optical Wireless Communication
ABSTRACT
Title of Thesis:
FREE-SPACE OPTICAL COMMUNICAITONS THROUGH A FOREST CANOPY Clinton Lee Edwards, Master of Science, 2004
Thesis Directed By:
Professor Christopher C. Davis, Department of Electrical and Computer Engineering
This paper models the effects of the leaves of mature broadleaf trees on air-to-ground free-space optical (FSO) communication systems operating through the leaf canopy. Ecological radiation transfer models are considered and the concept of Leaf Area Index (LAI) is reviewed and related to a probabilistic model. Leaf transmittance is experimentally measured for different leaf types and determined to be very close to zero. A probabilistic canopy model of foliage is developed as obscuring leaves are randomly distributed throughout the treetops. The expected fractional unobscured area statistic is derived as well as the variance around the expected value. Monte Carlo simulation results confirm the probabilistic model’s statistical conclusions. Multi-site passive optical measurements are taken in a mature broadleaf forest environment with increasing leaf obscuration then fitted to the model. The model’s implications to FSO system links are considered and simulated. Conclusions are discussed as well as further research.
FREE-SPACE OPTICAL COMMUNICAITONS THROUGH A FOREST CANOPY
by Clinton Lee Edwards
Thesis submitted to the Faculty of the Graduate School of the University of Maryland, College Park, in partial fulfillment of the requirements for the degree of Master of Science 2004
Advisory Committee: Professor Christopher C. Davis, Chair Professor William S. Levine Professor Thomas E. Murphy
© Copyright by Clinton Lee Edwards 2004
Dedication
I would like to dedicate this work to my wife, Corinne. She has supported my desire to further my education despite the abject poverty that is associated with being a graduate student. Only with her unflinching love and support, this work has been completed. I also
Title of Thesis:
FREE-SPACE OPTICAL COMMUNICAITONS THROUGH A FOREST CANOPY Clinton Lee Edwards, Master of Science, 2004
Thesis Directed By:
Professor Christopher C. Davis, Department of Electrical and Computer Engineering
This paper models the effects of the leaves of mature broadleaf trees on air-to-ground free-space optical (FSO) communication systems operating through the leaf canopy. Ecological radiation transfer models are considered and the concept of Leaf Area Index (LAI) is reviewed and related to a probabilistic model. Leaf transmittance is experimentally measured for different leaf types and determined to be very close to zero. A probabilistic canopy model of foliage is developed as obscuring leaves are randomly distributed throughout the treetops. The expected fractional unobscured area statistic is derived as well as the variance around the expected value. Monte Carlo simulation results confirm the probabilistic model’s statistical conclusions. Multi-site passive optical measurements are taken in a mature broadleaf forest environment with increasing leaf obscuration then fitted to the model. The model’s implications to FSO system links are considered and simulated. Conclusions are discussed as well as further research.
FREE-SPACE OPTICAL COMMUNICAITONS THROUGH A FOREST CANOPY
by Clinton Lee Edwards
Thesis submitted to the Faculty of the Graduate School of the University of Maryland, College Park, in partial fulfillment of the requirements for the degree of Master of Science 2004
Advisory Committee: Professor Christopher C. Davis, Chair Professor William S. Levine Professor Thomas E. Murphy
© Copyright by Clinton Lee Edwards 2004
Dedication
I would like to dedicate this work to my wife, Corinne. She has supported my desire to further my education despite the abject poverty that is associated with being a graduate student. Only with her unflinching love and support, this work has been completed. I also