Browsing by Department "Aerospace Engineering"
Now showing items 2140 of 149

Application Of The MCMC Method For The Calibration Of DSMC Parameters
(20150416)A Markov Chain Monte Carlo (MCMC) algorithm was employed to obtain a calibrated distribution for the hard sphere diameter, the VHS reference diameter, and the temperature viscosity exponent of argon, for use in the Direct ... 
An architecture for incorporating interactive visualizations into scientific simulations
(20150917)As scientific simulations get increasingly complex, so do the requirements of how to deal with the data that is produced. Few scientists and engineers today are satisfied with just looking at streams of numbers; we require ... 
Assessment of numerical differentiation methods for kinematic orbit solution of the GRACE mission
(20121207)The historical method of precise orbit determination is a dynamic approach. However, with the improvement of GPS tracking data and associated tracking networks, two newer methods have been developed: reduceddynamic and ... 
An assessment of the GPS L5 signal based on multiple vendor receivers
(20120221)The L5 signal of the Global Positioning System (GPS) is becoming available on an increasing number of Block IIF satellites. As the third civilian signal, L5 is superior in signal design to the L1 C/A and L2C civilian ... 
Automatic algorithm for accurate numerical gradient calculation in general and complex spacecraft trajectories
(20120221)An automatic algorithm for accurate numerical gradient calculations has been developed. The algorithm is based on both finite differences and Chebyshev interpolation approximations. The novelty of the method is an automated ... 
Characterization of Receiver Response to Spoofing Attacks
(The Institute of Navigation, 20120822)Test procedures are developed for characterizing the response of civil GPS receivers to spoofing attacks. Two response characteristics are analyzed in detail for four representative GPS receivers: (1) the spoofer power ... 
Characterization of Receiver Response to Spoofing Attacks
(20120822)Test procedures are developed for characterizing the response of civil GPS receivers to spoofing attacks. Two response characteristics are analyzed in detail for four representative GPS receivers: (1) the aggressiveness ... 
Characterizing The Cool KOIs. VII. Refined Physical Properties Of The Transiting Brown Dwarf LHS 6343 C
We present an updated analysis of LHS 6343, a triple system in the Kepler field which consists of a brown dwarf transiting one member of a widely separated M+M binary system. By analyzing the full Kepler data set and 34 ... 
Closedloop control of shock location to prevent hypersonic inlet unstart
(20140829)Hypersonic inlet unstart remains a major technical obstacle in the successful implementation of hypersonic airbreathing propulsion systems such as ramjets and scramjets. Unstart occurs when combustorinduced pressure ... 
A comparison of range and rangerate based GRACE gravity field solutions
(20110713)In the generation of the standard GRACE gravity fields, the KBand Ranging (KBR) system data is used in its rangerate mode. Because time derivatives attenuate the gravity signal relative to the data noise at the lower ... 
A comprehensive numerical model of Io's chemicallyreacting sublimationdriven atmosphere and its interaction with the Jovian plasma torus
(20120629)Io has one of the most dynamic atmospheres in the solar system due in part to an orbital resonance with Europa and Ganymede that causes intense tidal heating and volcanism. The volcanism serves to create a myriad of volcanic ... 
Computationally efficient path planning algorithm for autonomous navigation over natural terrain
(20130423)The present investigation focuses on the development of computationally efficient path planning algorithms for autonomous ground vehicles. The approach selected is based on a heuristic hill climbing local search. The cost ... 
Constrained attitude guidance and control for satellites
(20150121)To satisfy the requirements of small satellites with attitude control requirements, a guidance, navigation, and control module was designed at the Texas Spacecraft Laboratory. However, these small satellites tend to have ... 
Control algorithms and flight software framework for a spacecraft guidance navigation and control system
(20120210)This thesis presents a comparison of controller designs and a system software design for a general Guidance, Navigation and Control (GNC) system. The first part of the thesis investigates four control algorithms based on ... 
Control of mean separation in a compression ramp shock boundary layer interaction using pulsed plasma jets
(20140430)Pulsed plasma jets (also called "SparkJets'") were investigated for use in controlling the mean separation location induced by shock waveboundary layer interaction. These synthetic jet actuators are driven by electrothermal ... 
A critical evaluation of modern lowthrust, feedbackdriven spacecraft control laws
(20121206)Lowthrust spacecraft trajectory optimization is often a difficult and timeconsuming process. One alternative is to instead use a closedloop, feedbackdriven control law, which calculates the control using knowledge of ... 
CubeSat autonomous rendezvous and docking software
(20141217)An autonomous mission manager is being developed for use on CubeSats to perform proximity operations with other vehicles. The mission manager software is designed to run in realtime on a microprocessor used on a CubeSat. ... 
Decentralized probabilistic density control of swarm of autonomous agents with conflict avoidance constraints
(20140905)This report describes a method to control the density distribution of a large number of autonomous agents. The approach is based on the fact that there are a large number of agents in the system, and hence the time evolution ... 
Deformation monitoring using scanning synthetic aperture radar interferometry
(20121016)This dissertation provides the first demonstration of scanning synthetic aperture radar (ScanSAR) advanced interferometry processing for measuring surface deformation. ScanSAR data are synthesized from ERS1/2 stripmap ... 
Design and characterization of a printed spacecraft cold gas thruster for attitude control
(20140606)A threerotational degree of freedom attitude control system has been developed for the NASA Jet Propulsion Laboratory’s INSPIRE Project by the Texas Spacecraft Laboratory at The University of Texas at Austin. Using 3D ...