Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 33 for “"Laser communication"”.
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Nonlinear optics for frequency-doubling in nanosatellite laser communication
… to enable free space optical (FSO) communication links to take advantage of the ability to switch between two wavelengths using one transmit module. Our analysis shows that incorporating frequency-doubling with nonlinear optics into existing communication system designs can improve …
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Optomechanical and wavelength alignments of CubeSat laser communication Systems
… space missions more quickly at lower costs, the communication subsystems of the platform are limited by a heavily regulated and overcrowded RF spectrum. Scientific instruments with increasing capabilities on CubeSats are generating massive amounts of data and are quickly pushing the boundaries of …
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Spatial tracker for an air-to-ground laser communication link
… of a spatial tracker for an air-to-ground laser communication system; these include a PWM switching amplifier and the control systems for driving the primary steering and tracking elements required in the acquisition and maintenance of an optical communication link. The hardware was …
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System-Theoretic Process Analysis of a Novel Airborne Laser Communication System
… strives to create a more robust battle network, laser communication offers many advantages such as supporting more secure and efficient data sharing. For this reason, interest has grown in recent years in implementing lasercom as a means for intra-aircraft communication. However, many challenges …
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High-order compensation of self-phase modulation in laser communication systems
… that reduces signal-to-noise ratio in free-space laser communication systems which use a fiber to connect their transmitter's high-power optical amplifier to its telescope optics. The effects of SPM can be mitigated by using a phase modulator to down-chirp pulses before passing through the …
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Pointing acquisition and tracking design and analysis for CubeSat Laser communication
… proposes a low size, weight, and power (SWaP) laser communication pointing, acquisition, and tracking (PAT) design for CubeSats in low earth orbit (LEO). As data production on-orbit continues to grow due to sensor miniaturization and the increased prevalence of satellites in LEO, current RF …
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An earth image simulation and tracking system for the Mars Laser Communication Demonstration
… Earth-tracking algorithms for the Mars Laser Communication Demonstration (MLCD). The MLCD mission will demonstrate the feasibility of high-data-rate laser communications between a Mars orbiting satellite and an Earth ground station. One of the key challenges of the mission is the …
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A noise-gated PLL for clock recovery in a free-space laser communication system
… system for data clock recovery in a free-space laser communication application. The clock recovery unit is designed to operate at extremely low optical received power, tolerate a fading channel, and also account for Doppler effects. I explored the feasibility of adding a noise-gating system to …
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Impact of the boundary layer on pointing and tracking in airborne free-space laser communication links
Free-space laser communication is a developing technology with enormous potential to revolutionize the way people communicate across the globe. Of specific interest are air-to-space lasercom links. Such a link experiences atmospheric scintillation, platform jitter, and boundary layer turbulence. …
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Simulating the use of channel reciprocity in laser communication system operations to improve quality of service through varying atmospheric conditions
… The first was to create a numerical model of a laser communications system that included either channel reciprocity or interleaving to mitigate the effects of atmospheric turbulence. This model was implemented in MATLAB* and Simulink*. The second task integrated the model with a graphical user …
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An Advanced Fast Steering Mirror for optical communication
… suited to beam stabilization tasks in laser communication, lidar, and similar optical applications. In fact, work on the Mars Laser Communication Demonstration project at MIT Lincoln Laboratory provided the original impetus for developing the subject technology. My work on this project …
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Laser beacon tracking for free-space optical communication on small-satellite platforms in low-earth orbit
Free-space optical (FSO) communication, or laser communication, is capable of providing high-rate communication links, meeting the growing downlink demand of space missions, including those on small-satellite platforms. FSO communication takes advantage of the high-gain nature of narrow laser beams …
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Commanding, Telemetry, and Software Strategy for CubeSat Laser Infrared CrosslinK (CLICK) Mission
… operations of the NASA-sponsored Cubesat Laser Infrared CrosslinK (CLICK) B/C mission [1] [2]. This twin-cubesat mission will demonstrate peer-to-peer laser-communication capabilities novel at this small terminal scale. Optical laser communication terminals can have lower Size, Weight, and …
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The refractive effects of laser propagation through the ocean and within the ocean
… the effect of the ocean water attenuation on a laser beam fired upward inside the ocean. The laser beam spreading due to scattering is approximated. The method used is a computer Monte Carlo simulation. Angular spreading of light caused by refraction at the sea surface is also studied and …
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A software-defined receiver for laser communications using a GPU
Laser commiunication systems provide a high data rate, power efficient communication solution for small satellites and deep space missions. One challenge that limits the widespread use of laser communication systems is the lack of accessible, low-complexity receiver electronics and software …
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Capacity of and coding for multiple-aperture, wireless, optical communications
… causes random power fluctuations in optical communication systems, making communication through the atmosphere difficult. This same phenomenon makes the stars twinkle at night, and pavement shimmer on a hot summer day. True to the old adage, "don't put all your eggs in one basket," we examine …
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100 Gbps ptical coherent modem for low earth orbit optical inter-satellite links
Free space optical communication (FSOC) provides a viable and cost-effective solution for future satellite systems with advantages in bandwidth, unregulated frequencies, and reduced system mass, volume, and power consumption in comparison with radio frequency systems. Several FSOC systems …
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Design and Performance Analysis of Frequency-Shift Keyed Transmitter using Rapidly Tunable Lasers
… multi-Gb/s channel bandwidths. For free-space laser communication (lasercom) applications, links are usually point-to-point, have narrow beamwidths, and do not need to share a transmitting medium with other signals. Therefore, many lasercom applications could exploit the benefits of FSK by …
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Liquid lens beam steering and environmental testing for the miniature optical steered antenna for inter-satellite communication
… to achieve wide-angle beam steering for CubeSat laser communication (lasercom) crosslinks. Liquid lenses are lenses that can non-mechanically alter focal length based on an applied voltage or current. We evaluate two commercial liquid lens manufacturers, Corning Varioptic and Optotune. Corning …
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Design of a small fast steering mirror for airborne and aerospace applications
… requirements based on a realistic deep-space laser communication mission, magnetic equivalent circuit and three-dimensional magnetostatic finite element analysis of the actuator, and a 3D structural optimization of the moving armature modal frequencies. The resulting design is one iteration …
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