Browsing by Department "Aerospace Engineering and Engineering Mechanics"
Now showing items 1-20 of 234
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Ablation onset in unsteady hypersonic flow about nose-tips with a forward-facing cavity
(2001-08)A forward-facing cavity is examined as a means of reducing the severe heating and delaying ablation onset at the nose-tip of a hypersonic vehicle. Whereas previous studies have concentrated on heating rates alone, the ... -
Accuracy Limits for Globally-Referenced Digital Mapping Using Standard GNSS
(IEEE, 2018)Exchange of location and sensor data among connected and automated vehicles will demand accurate global referencing of the digital maps currently being developed to aid positioning for automated driving. This paper ... -
Adaptive Estimation of Signals of Opportunity
(2014-04)To exploit unknown ambient radio frequency signals of opportunity (SOPs) for positioning and navigation, one must estimate their states along with a set of parameters that characterize the stability of their oscillators. ... -
Adaptive interplanetary orbit determination
(2000-08)This work documents the development of a real-time interplanetary orbit determination monitoring algorithm for detecting and identifying changes in the spacecraft dynamic and measurement environments. The algorithm may ... -
Adaptive output feedback controllers for a class of nonlinear mechanical systems
(2002)Even from the early days of adaptive control theory, it has been a primary target for several researchers to guarantee global stability using as limited assumptions as possible. Currently, there exist applicable theories ... -
Advanced navigation algorithms for precision landing
(2007-12)A detailed analysis of autonomous navigation algorithms to achieve autonomous precision landing is presented. The problem of integrated attitude determination and inertial navigation is solved. The theoretical results ... -
Advances in GNSS Equipment
(2010) -
Analysis and order reduction of an autonomous lunar lander navigation system
(2009-08)A navigation system for precision lunar descent and landing is presented and analyzed. The navigation algorithm is based upon the extended Kalman Filter and employs measurements from an inertial measurement unit to propagate ... -
Analysis of Ionospheric Scintillations using Wideband GPS L1 C/A Signal Data
(2004)A non-real-time GPS receiver has been developed and tested for use in scintillation analysis. The receiver consists of a digital storage receiver and non-real-time software acquisition and tracking algorithms. The goal ... -
Application of automatic differentiation to trajectory optimization via direct multiple shooting
(2003)Automatic differentiation, also called computational differentiation and algorithmic differentiation, is the process of computing the derivatives or Taylor series of functions from the computer source code implementing ... -
Assessing the Spoofing Threat: Development of a Portable GPS Civilian Spoofer
(2008)A portable civilian GPS spoofer is implemented on a digital signal processor and used to characterize spoofing effects and develop defenses against civilian spoofing. This work is intended to equip GNSS users and receiver ... -
Assured Navigation and Timing
(2017-09-28) -
Attitude dynamics stabilization with unknown delay in feedback control implementation
(2009-12)This work addresses the problem of stabilizing attitude dynamics with an unknown delay in feedback. Two cases are considered: 1) constant time-delay 2) time-varying time-delay. This is to our best knowledge the first ... -
Automated generation and optimization of ballistic lunar capture transfer trajectories
(2009-08)The successful completion of the Hiten mission in 1991 provided real-world validation of a class of trajectories defined as ballistic lunar capture transfers. This class of transfers is often considered for missions to the ... -
Automotive Collision Risk Estimation Under Cooperative Sensing
(IEEE, 2020)This paper offers a technique for estimating collision risk for automated ground vehicles engaged in cooperative sensing. The technique allows quantification of (i) risk reduced due to cooperation, and (ii) the increased ... -
Automotive-Radar-Based 50-cm Urban Positioning
(IEEE, 2020)Deployment of automated ground vehicles (AGVs) beyond the confines of sunny and dry climes will require sub-lane-level positioning techniques based on radio waves rather than near-visible-light radiation. Like human sight, ... -
A Blueprint for Civil GPS Navigation Message Authentication
(2014-05)A proposal for civil GPS navigation message authentication (NMA) is presented with sufficient specificity to enable near-term implementation. Although previous work established the practicality and efficacy of NMA for ... -
CASES: A Novel Low-Cost Ground-based DualFrequency GPS Software Receiver and Space Weather Monitor
(2011)GPS receivers can be used for monitoring space weather events such as TEC variations and scintillation. This paper describes the new GPS sensor developed by ASTRA, Cornell and UT Austin. The receiver is called “Connected ... -
CASES: A Smart, Compact GPS Software Receiver for Space Weather Monitoring
(2011)A real-time software-defined GPS receiver for the L1 C/A and L2C codes has been developed as a low-cost space weather instrument for monitoring ionospheric scintillation and total electron content. The so-called CASES ...
