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For acquisition of narrow-beam free-space optical (FSO) terminals, a Global Positioning System (GPS) is typically required for coarse localization of the terminal. However, the GPS signal may be shadowed, or may not be present at all, especially in rough or unnameable terrains. In this study, we propose a lidar-assisted acquisition of an unmanned aerial vehicle (UAV) for FSO communications in a poor GPS environment. Such an acquisition system consists of a lidar subsystem and an FSO acquisition subsystem: The lidar system is used for coarse acquisition of the UAV, whereas, the FSO system is utilized for fine acquisition to obtain the UAV’s accurate position. This study investigates the optimal allocation of energy between the lidar and FSO systems to minimize the acquisition time. Here, we minimize the average acquisition time, and maximize the cumulative distribution function of acquisition time for a fixed threshold. We learn that an optimal value of the energy allocation factor exists that provides the best performance of the proposed system.

<p>Free-space optical (FSO) communication is a potential technology for last-mile applications. Key advantages are the unlicensed spectrum, high transmission rates, and inherent security. Moreover, Radio-over-FSO (RoFSO) allows seamless integration between the incompatible radio frequency (RF) and optical networks. Such advantages qualify FSO systems to take a front seat in next-generation broadband communication networks. However, the main challenge for FSO systems is the performance degradation imposed by the atmospheric attenuation and turbulence. To exploit the advantages of FSO systems, accurate and computationally-efficient channel models are required. This thesis represents in-field experimental work related to FSO channel measurement as well as the transmission of orthogonal frequency division multiplexing (OFDM) over the FSO channel. A 1.87-km FSO link installed at McMaster University is employed. A high-speed field-programmable gate array (FPGA)-based digitizer board is used as the underlying hardware platform for interface with the link. A system-on-three-FPGAs is implemented to act as a universal transceiver for signals composed using MATLAB. A new technique is developed for conducting the FSO channel measurement. An optical signal intensity-modulated by a high frequency sinusoid is transmitted. The received signal undergoes a fast-Fourier transform (FFT) to filter out a large portion of the interfering noise providing more accurate measurements. Fitting with the log-normal distribution is investigated. A finite-state Markov model is also derived and its accuracy is verified by the simulation results. The first realization of an in-field OFDM over FSO transmission system is implemented and tested over the link. The received signal is investigated on the symbol level and constellation diagrams are visualized. Transmission rates up to 300 Mbps are achieved with average symbol-error rate (SER) on the order of 10^-6.</p> / Master of Applied Science (MASc)

Quantum Key Distribution (QKD) is a promising method for information exchange that relies on quantum mechanical principles to increase the security of encodedinformation in comparison with traditional cryptography. The objective of this degree project was to plan, build and validate a receiver system for Free-Space QKD. To testit, a simple state-preparation setup was built, using a 780 nm laser for the QKD channel and a 680 nm laser for tracking, and both were sent over a single free-spacequantum channel. On the receiver side, the beam is received by a telescope that focuses it into the eye-opening where the receiver is positioned. Here, the tracking laser isdeflected to a camera (intended for a tracking algorithm, to be implemented in the future) and the QKD laser beam is split, and its polarization measured in |H⟩/|V⟩ and|+⟩/|−⟩ basis. Finally, the system is validated by testing that the beam propagates over the free-space channel, that the polarization correction is properly applied and,finally, that each polarization is routed into the right detector. By replacing the test sender with another with a capacity for sending states random number generation, thedeveloped receiver should be able to take part in quantum communication via protocols such as BB84, B92 or Decoy-State. / Kvantnyckeldistribution (QKD) är en lovande metod för informationsutbyte som förlitar sig på kvantmekaniska principer för att öka säkerheten för kodad informationjämfört med traditionell kryptografi. Syftet med detta examensprojekt var att planera, bygga och validera ett mottagarsystem för Fritt Rymd QKD. För att testa det,byggdes en enkel state-preparation setup, med hjälp av en 780 nm laser för QKD kanal och en 680 nm- laser för spårning, och båda skickades över en enda fri-rymdkvantkanal. På mottagarens sida tas strålen emot av ett teleskop som fokuserar den i ögonöppningen där mottagaren är placerad. Här avlägsnas spårningslasern till enkamera (som är avsedd för en spåringsalgoritm, som ska genomföras i framtiden) och QKD-laserstrålen är uppdelad, och polariseringen mäts i |H⟩/|V⟩ och |+⟩/|−⟩ bas.Slutligen valideras systemet genom att testa att strålen sprider sig över den fria rymdkanalen, att polariseringskorrigering tillämpas korrekt och, slutligen, att varjepolarisering riktas till rätt detektor. Genom att ersätta testsändaren med en annan med en kapacitet för att sända stater slumptalsgenerering, bör den utvecklademottagaren kunna delta i kvantkommunikation via protokoll som BB84, B92 eller Decoy-State.

In the first chapter, a Q-switched fiber laser that is capable of generating transform-limited pulses based on single-frequency fiber laser seeded ring cavity is demonstrated. The output pulse width can be tuned from hundreds of nanoseconds to several microseconds. This Q-switched ring cavity fiber laser can operate over the whole C-band. In addition, a theoretical model is developed to numerically study the pulse characteristics, and the numerical results are in good agreements with the experimental results. In the next chapter, a Raman fiber laser is developed for generating signal at 1480 nm. Initial experimental results has demonstrated generating of Raman laser at 1175 nm, 1240 nm, 1315 nm, and 1395 nm wavelength. Finally, a free space fiber amplifier is studied both theoretically and experimentally. The experimental work has demonstrated signal coupling efficiency up to 90% in the NP highly Er/Yb co-doped phosphate fiber.

Alate morphs can benefit aphid populations by facilitating dispersal from deteriorating food sources and by escaping from natural enemies. Wing development, however, imposes constraints on fecundity. The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is an important economic pest in the U.S. and Canada. I conducted a series of laboratory and field experiments to determine the environmental factors inducing wing development in this species, and to determine the effects of asexual alate individual production on an A. glycines population under predation. My results reveal that wing induction in A. glycines occurs in response to interactions between crowding and decreased plant quality cues, and that alate aphid production benefits an aphid population under predation by increasing prevalence at a temporary cost to fecundity. My results contribute to the growing knowledge on the production of asexual alate aphids and provide insight into the biology of A. glycines as an agricultural pest. / May 2017

Les télécommunications laser en espace libre sont limitées en portée par la turbulence atmosphérique. L'optique adaptative, par la correction de la phase turbulente à l'émission du faisceau, a permis d'étendre leur domaine d'exploitation.Toutefois, sur de longues distances de propagation, cette correction n'est plus suffisante et il faut également précompenser l'amplitude du faisceau émis. De premières études numériques ont montré que le principe de retournement temporel, ou plus exactement de conjugaison de phase bidirectionnelle itérative, conduirait à des conditions satisfaisantes de focalisation du faisceau laser en fort régime de turbulence.Le principe de conjugaison de phase n'ayant été étudié que théoriquement jusque-là, mon travail de thèse s'est attaché à mettre en oeuvre un démonstrateur expérimental pour quantifier les performances de cette technique dans des conditions maîtrisées. En parallèle, une simulation de bout en bout de l'expérience a permis d'évaluer l'influence d'erreurs d'étalonnage sur les performances finales de la correction et de valider les résultats expérimentaux obtenus. Les points durs de la mise en oeuvre d'un système de télécommunications laser en espace libre ont ainsi été identifiés.L'ensemble de ces travaux constitue la toute première démonstration expérimentale du principe de retournement temporel optique. D'autres domaines d'application comme les lasers de puissance ou la propagation à travers des milieux biologiques très diffusants, nécessitant également de corriger le faisceau à l'émission, sont concernés. / Free Space Optical communications (FSO) are range limited due to atmospheric turbulence. Adaptive optics can mitigate turbulence effects by adding a phase modulation on the emitted laser beam. However, both phase and amplitude modulation are needed to perform long range FSO. Previous numerical studies have shown that iterative phase conjugation is an efficient modulation technique for lasercom systems.This PhD thesis is dedicated to the development and the realization of the first experimental demonstration of the iterative phase conjugation principle in a controlled turbulence environment. An optical bench, representative of a long range propagation through strong turbulence, has been scaled down to few-meters propagation in visible.Several methods for complex field measurement and modulation are numerically studied. Selected methods are implemented and tested, such as a novel focal plane technique for complex field measurement. Finally, iterative phase conjugation is performed and results cross-correlated with an end-to-end model representative of the optical bench.This work is the first experimental demonstration of the optical phase conjugation principle. Applications can be found in other fields than lasercoms, such as high power lasers or propagation through highly diffusing biological tissues, both in need of laser emission modulation.

Approved for public release, distribution is unlimited / This thesis sought to design and implement a low-cost, portable, Free-Space Optics (FSO) communications device for Ethernet applications. Under some circumstances such a device would have utility at a Combat Operations Center (COC), a Field Artillery Position, or wherever else fiber optic cable is used in garrison or field. The design was based on commercial off the shelf components originally designed for fiber optic applications. Based on a 155 megabits per second (Mbps) media converter, the design used two fiber optic transceivers, coupled to collimating lenses to pass data over free-space. Sustained data rate of 100 Mbps was achieved with full network functionality on the optical bench with a low-power (0.5mW) laser diode transmitter without focusing optics on the receiver. The laser diode power(mounted on device), was measured with acceptable losses up to 300 ft during testing using a photodiode with focusing optics. The findings indicate that the system with proper collecting optics could be optimized for free-space communication at short to moderate ranges. / Captain, United States Marine Corps

Technology for wireless information access has enabled innovation of 'smart' portable consumer devices. These have been widely adopted and have become an integral part of our daily lives. They need ubiquitous connectivity to the internet to provide value added services, maximize their functionality and create a smarter world to live in. Cisco's visual networking index currently predicts wireless data consumption to increase by 61% per year. This will put additional stress on the already stressed wireless access network infrastructure creating a phenomenon called 'spectrum crunch'. At the same time, the solid state devices industry has made remarkable advances in energy efficient light-emitting-diodes (LED). The lighting industry is rapidly adopting LEDs to provide illumination in indoor spaces. Lighting fixtures are positioned to support human activities and thus are well located to act as wireless access points. The visible spectrum (380 nm - 780 nm) is yet unregulated and untapped for wireless access. This provides unique opportunity to upgrade existing lighting infrastructure and create a dense grid of small cells by using this additional 'optical' wireless bandwidth. Under the above model, lighting fixtures will service dual missions of illumination and access points for optical wireless communication (OWC). This dissertation investigates multiple-input multiple-output (MIMO) optical wireless broadcast system under unique constraints imposed by the optical channel and illumination requirements. Sample indexed spatial orthogonal frequency division multiplexing (SIS-OFDM) and metameric modulation (MM) are proposed to achieve higher spectral efficiency by exploiting dimensions of space and color respectively in addition to time and frequency. SIS-OFDM can provide significant additional spectral efficiency of up to (Nsc/2 - 1) x k bits/sym where Nsc is total number of subcarriers and k is number of bits per underlying spatial modulation symbol. MM always generates the true requested illumination color and has the potential to provide better color rendering by incorporating multiple LEDs. A normalization framework is then developed to analyze performance of optical MIMO imaging systems. Performance improvements of up to 45 dB for optical systems have been achieved by decorrelating spatially separate links by incorporating an imaging receiver. The dissertation also studies the impact of visual perception on performance of color shift keying as specified in IEEE 802.15.7 standard. It shows that non-linearity for a practical system can have a performance penalty of up to 15 dB when compared to the simplified linear system abstraction as proposed in the standard. Luminous-signal-to-noise ratio, a novel metric is introduced to compare performance of optical modulation techniques operating at same illumination intensity. The dissertation then introduces singular value decomposition based OWC system architecture to incorporate illumination constraints independent of communication constraints in a MIMO system. It then studies design paradigm for a multi-colored wavelength division multiplexed indoor OWC system.

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2019-02-25T23:03:33Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Zíngara Rocio dos Santos Eurich.pdf: 8759248 bytes, checksum: 68d4f63e6564948c318741b1d8432b4d (MD5) / Made available in DSpace on 2019-02-25T23:03:33Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Zíngara Rocio dos Santos Eurich.pdf: 8759248 bytes, checksum: 68d4f63e6564948c318741b1d8432b4d (MD5) Previous issue date: 2018-09-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Após uma longa trajetória, as praças permanecem presentes no desenho urbano e no imaginário de toda a população citadina. Sem perder sua principal função, a social, são trazidas como tema dessa pesquisa, com o objetivo de avaliar a qualidade destes espaços na cidade de Ponta Grossa, por meio de uma proposta metodológica. Para tanto foi necessário um levantamento bibliográfico sobre o tema além de metodologias capazes de avaliar qualiquantitativamente a arborização e infraestrutura das praças e analisar os aspectos espaciais, para que então fossem encontradas as variáveis necessárias para a composição de um Índice de Qualidade de Praças. Para se chegar ao índice final, denominado de IQP – Índice de Qualidade de Praças, foram considerados sub-índices ligados às principais funções das praças, denominados: Índice da Função Ambiental – IFA; Índice da Função Econômica – IFE e Índice da Função Social - IFS, uma vez que de acordo com a tese proposta, é o cumprimento destas funções que expressa a qualidade das praças. O intuito da pesquisa além de promover e valorizar os espaços livres públicos da cidade, sobretudo as praças, foi também apresentar o IQP como uma ferramenta de levantamento e análise dos dados. Todos os índices propostos variam de 0 a 1 e correspondem aos seguintes intervalos: 0 - 0,25 péssimo; 0,26 – 0,50 regular; 0,51 – 0,75 bom e 0,76 – 1 ótimo. Quanto aos resultados concernentes à distribuição espacial das praças verificou-se que algumas áreas consideradas pela Prefeitura Municipal de Ponta Grossa como praças se comportam como espaço sem função social direta, estas foram desconsideradas nas análises. Ao iniciar os resultados com uma análise geral das condições das praças verificou-se que há uma concentração das mesmas na área central da cidade, bem como nos bairros Uvaranas e Neves. Nas praças levantadas foram encontrados 1.936 indivíduos arbóreos dos quais 59,8% são de origem exótica. Quanto a infraestrutura, a iluminação, os caminhos e os bancos foram as estruturas mais frequentes. Quanto aos sub-índices o que obteve o maior valor foi o IFE que alcançou 0,85, o IFA alcançou 0,52 e o IFS 0,51. A partir do cálculo dos sub-índices obteve-se o IQP para a área urbana, por bairro e para cada praça. O IQP médio para as praças da cidade de Ponta Grossa resultou em 0,53, classificado como bom. O IQP mais alto foi apresentado pela praça Rotary Internacional com 0,89 e o valor mais baixo foi verificado para a praça Ambiental Jacobus Van Wilpe com 0,12. A partir dos resultados observa-se um cenário heterogêneo no que tange a qualidade desses espaços e observa-se que as variáveis da função social são as que necessitam de uma maior intervenção por parte do poder público, sendo a segurança, estética e distribuição as mais afetadas. Essas intervenções fariam com que Assim as praças conseguissem cumprir integralmente suas funções de grande importância para a população, assim como para todo o espaço urbano. / After a long trajectory, the squares remain present in the urban space and in the imaginary of the city population. Without losing its main function, the social, they are brought as a theme of this research, with the purpose of evaluating the quality of these spaces in the city of Ponta Grossa, through a methodological proposal. For this, it was necessary a bibliographic survey besides methodologies able of evaluating quantitative and quatitative the arborization and infrastructure of the squares and analyzing the spatial aspects, it was necessary found variables for the composition of a Quality Index of Squares. In order to reach the final index, denominated IQP - Quality Index of Squares, were considered sub-indices linked to the main functions of the squares, denominated: Index of the Environmental Function - IFA; IFS and Social Function Index - IFS, since according to the proposed thesis, it is the fulfillment of these functions that expresses the quality of the squares. The aim of the research, besides promoting and valuing the public spaces of the city, especially the squares, was also to present the IQP as a data collection and analysis tool. All proposed indexes vary from 0 to 1 and correspond: 0 - 0,25 bad; 0.26-0.50 regular; 0.51 - 0.75 good and 0.76 - 1 optimum. Regarding the results concerning the spatial distribution of the squares, it was verified that some areas considered by the City of Ponta Grossa as squares behave as space without direct social function, these were disregarded in the analyzes. When starting the results with a general analysis of the conditions of the squares it was verified that there is a concentration of the same in the central area of the city, as well as in the neighborhoods Uvaranas and Neves. In the squares were found 1,936 arboreal individuals of which 59.8% are of exotic origin. Infrastructure, lighting, sidewalk and banks were the most frequent structures. As for the sub-indices, the highest value was the IFE that reached 0.85 and IFA the index that obtained the lowest value, 0.52. Soon followed by the IFS with 0.51. From the calculation of the sub-indices the IQP was obtained for the urban area, by neighborhood and for each square. The average IQP for the squares of the city of Ponta Grossa resulted in 0.53, classified as good. The highest IQP was presented by Rotary Internacional with 0.89 and the lowest value was verified for Ambiental Jacobus Van Wilpe square with 0.12. From the results, a heterogeneous scenario is observed regarding the quality of these spaces and the variables require an intervention by the government, so that the squares can fully fulfill their functions of big importance for the population, as well as for all the urban space.