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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design and Development of Ground Segment Software and Hardware for Nanosatellie Space Missions

Mehradnia, Payam 05 December 2013 (has links)
Contributions to two nanosatellite missions are discussed. First, the design and development of a test system for an advanced nanosatellite power board is discussed. Details of software and hardware design process involved in the implementation of automated test procedures are presented. The system has been deployed for unit-level testing of power boards for several nanosatellite missions, significantly reducing testing cost and time. Next, a Mission Planning and Scheduling Software platform is proposed for Earth Observation missions. The motivation is described for the development of a stand-alone application enabling satellite operations teams to identify suitable observation scenario parameters. Attitude and orbital trajectory estimation algorithms constituting the computational model are integrated and implemented within a graphical visualization environment to allow interaction with the user in an efficient and intuitive manner. Key results of major component-level testing are presented, showing the behaviour and accuracy of analytical components satisfy mission requirements.
2

Design and Development of Ground Segment Software and Hardware for Nanosatellie Space Missions

Mehradnia, Payam 05 December 2013 (has links)
Contributions to two nanosatellite missions are discussed. First, the design and development of a test system for an advanced nanosatellite power board is discussed. Details of software and hardware design process involved in the implementation of automated test procedures are presented. The system has been deployed for unit-level testing of power boards for several nanosatellite missions, significantly reducing testing cost and time. Next, a Mission Planning and Scheduling Software platform is proposed for Earth Observation missions. The motivation is described for the development of a stand-alone application enabling satellite operations teams to identify suitable observation scenario parameters. Attitude and orbital trajectory estimation algorithms constituting the computational model are integrated and implemented within a graphical visualization environment to allow interaction with the user in an efficient and intuitive manner. Key results of major component-level testing are presented, showing the behaviour and accuracy of analytical components satisfy mission requirements.
3

Optimal Allocation of Satellite Network Resources

Burrowbridge, Sarah Elizabeth 31 December 1999 (has links)
This work examines a straightforward solution to a problem of satellite network resource allocation by exploring the application of an optimal algorithm to a subset of the general scheduling problem. Making some basic simplifications, such as the limitation of the mission scenarios to Low Earth Orbiting satellites, allows the effective application of the rigorous methods of the Greedy Activity-Selector algorithm. Tools such as Analytical Graphic's Satellite Tool Kit and MATLAB 5.0 are integrated to assist in the implementation of the algorithm. Several examples are presented in order to illustrate the effectiveness of the process. / Master of Science
4

Adaptive Critic Design Techniques for Mobile Transmitter Path Planning

Rivera, Grant 10 1900 (has links)
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / In geometrically complex indoor industrial environments, such as factories, health care facilities, or offices, it can be challenging to determine where each telemetry receiver needs to be located to collect data from one or more mobile transmitters. Accurately estimating the areas that each transmitter frequently travels, rarely travels, and quickly travels through, helps to simplify the telemetry system planning problem and establishes which areas may be acceptable to provide marginal coverage. This paper discusses how using A* (A-Star) for transmitter path planning can assist in the telemetry system planning problem.
5

Uranus orbiter and probe mission : Project Upsilon

Lu, Jason Yunhe 01 October 2014 (has links)
Project Upsilon is a proposed NASA Flagship Class, Uranus Orbiter and Probe mission concept to investigate Uranus' planetary magnetic field and atmosphere. Three spacecraft - the Upsilon-0 Propulsion Module, the Upsilon-1 Science Orbiter, and the Upsilon-2 Atmosphere Probe - shall be implemented to meet needs, goals, and objectives as stated by the NASA Solar System Planetary Science Decadal Survey 2013-2022. Upsilon-0 shall be expended in order to complete orbital capture about Uranus. Upsilon-1 shall study Uranus' planetary magnetic field, obtaining real-time measurements for nominally 20 months within the first two years of arrival; and for as long as possible after the first two years, as part of an extended science mission. Upsilon-2 shall be descended into Uranus' cloud tops to obtain physical data and imagery well into the atmosphere's depths. Chemical propulsion is employed in place of solar-electric propulsion, with regard to the interplanetary system-level trade tree. The interplanetary trajectory requires a single un-powered flyby of Jupiter, selected among several flyby node configurations. The science orbit produces nearly repeating latitude-longitude tracks over a rotating Uranus. The statistical estimation method combines an orbit determination model with respect to Uranus' flattening, and a simple magnetic dipole model for field line modeling. A 7-year period is allotted for the technology research and development, and the testing and verification stages of the project life cycle; the interplanetary journey to Uranus requires 21 years; and the nominal in-situ operation lifetime is 2 years. The Project Upsilon spacecraft launch in 2021 to "revolutionize our understanding of ice giant properties and processes, yielding significant insight into their evolutionary history"; contributing to the Planetary Science Decadal Survey's, and NASA's, key planetary science and deep space exploration visions. / text
6

Mission planning tool for small satellites

Mathieu, Perrine 22 April 2014 (has links)
The Texas Spacecraft Laboratory (TSL) at the University of Texas at Austin is currently planning to launch two CubeSat missions in 2014. Innovations are more readily attempted on such low-risk small satellites than with higher-cost payloads, which puts CubeSats at the forefront of space research. The TSL CubeSats will thus be used to pioneer and demonstrate new on-orbit technology. Due to the innovative aspect of the CubeSat missions, limited prior experience exists with the technology used. It is thus important to have an accurate understanding of mission operations prior to launch through computer simulation. In order to improve the success and reliability of current and future TSL missions, a MATLAB tool was developed to simulate on-orbit operations. The various capabilities of the user-friendly tool developed include power budget calculations, pass determination and orbit simulation. The comprehensive program can predict the life of the spacecraft at critical moments of its operation and, in general, help improve understanding of how to successfully meet mission requirements and design mission operations. / text
7

Multi-Objective Heterogeneous Multi-Asset Collection Scheduling Optimization with High-Level Information Fusion

Muteba Kande, Joel 18 August 2021 (has links)
Surveillance of areas of interest through image acquisition is becoming increasingly essential for intelligence services. Several types of platforms equipped with sensors are used to collect good quality images of the areas to be monitored. The evolution of this field has different levels: some studies are only based on improving the quality of the images acquired through sensors, others on the efficiency of platforms such as satellites, aircraft and vessels which will navigate the areas of interest and yet others are based on the optimization of the trajectory of these platforms. Apart from these, intelligence organizations demonstrate an interest in carrying out such missions by sharing their resources. This thesis presents a framework whose main objective is to allow intelligence organizations to carry out their observation missions by pooling their platforms with other organizations having similar or geographically close targets. This framework will use Multi-Objective Optimization algorithms based on genetic algorithms to optimize such mission planning. Research on sensor fusion will be a key point to this thesis, researchers have proven that an image resulting from the fusion of two images from different sensors can provide more information compared to the original images. Given that the main goal for observation missions is to collect quality imagery, this work will also use High-Level Information Fusion to optimize mission planning based on image quality and fusion. The results of the experiments not only demonstrate the added value of this framework but also highlight its strengths (through performance metrics) as compared to other similar frameworks.
8

Optimizing Stakeholder Objectives Of Space Exploration Architectures Using Portfolio Optimization

William John O'Neill (9757196) 14 December 2020 (has links)
The large number and significant variety of systems available for space exploration missions produce countless potential architecture combinations. Compounding this are the scheduling intricacies of system life-cycle phases, time dependent operational dependencies, as well as the uncertainty associated with each system and technology in terms of cost, schedule, and performance. Traditional architecting emphasizes the individual design of component systems over the wide-ranging and robust assessment of architecture options early in mission design. A top down method that can assess the capabilities, requirements, and risks associated with the diversity of available space systems and form optimal portfolios of interdependent systems is necessary. This dissertation describes and demonstrates a portfolio optimization technique that can de-sign and assess Lunar space exploration architectures by optimizing on programmatic objectives such as cost, performance, schedule, and robustness while simultaneously accounting for system operational interdependencies and schedule dependencies of the selected systems. Several specific enhancements to the Robust Portfolio Optimization method are produced, resulting in the the novel Progarmamtic Portfolio Optimization (PPO) approach: including life-cycle phase modeling, variable capability sizing of systems, and multi-domain constraints to model time dependent objectives.<br>
9

Mission Planning and Instrument Design for Stellar Occultation Measurements of Lower Thermospheric Nitric Oxide in the Polar Night

Jones, Nicholas Alexander 05 July 2023 (has links)
An ultraviolet instrument compatible with a CubeSat form factor is currently being developed at Virginia Tech for the purpose of measuring nitric oxide in the polar night through the stellar occultation technique. This instrument will allow the investigation of how the Sun and Earth systems are related via energetic particle precipitation in the auroral regions. The work performed in this thesis supports the instrument design and requirements development by modelling the stellar occultation geometry to identify orbit parameters and target stars that could yield nitric oxide measurements during the polar winter at consistent latitudes, to best observe the build-up and fall-off of nitric oxide. The orbit study was accomplished through the development of an open-source tool in MATLAB, the Stellar Occultation Mission Planner. The results of this analysis were used to model the instrument performance and identify the required narrowband filter parameters to meet science requirements. Additional studies were performed to explore system performance for a future flight opportunity. / Master of Science / A small, light weight instrument is being designed at Virginia Tech to allow for nitric oxide in the atmosphere to be measured during the long polar nights that occur during winter in the Arctic and Antarctic regions. This instrument will allow scientists to explore how the Sun and Earth interact through space weather at high latitudes. This will be accomplished by using star light to probe the atmosphere while the instrument is onboard a small spacecraft called a CubeSat. The work performed in this thesis simulated the spacecraft orbit to determine which stars yielded the best measurements over the course of the polar night. Using these results, the instrument performance was simulated to inform the design of a filter for the instrument. Additional studies were performed to support the design of a future mission to fly the instrument in space.
10

Mapping Traffic Flow for Telemetry System Planning

Rivera, Grant 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / Telemetry receivers must typically be located so that obstacles do not block the signal path. This can be challenging in geometrically complex indoor environments, such as factories, health care facilities, or offices. An accurate method for estimating the paths followed by typical telemetry transmitters in these environments can assist in system planning. It may be acceptable to provide marginal coverage to areas which are rarely visited, or areas which transmitters quickly transit. This paper discusses the use of the ant colony optimization and its application to the telemetry system planning problem.

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