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Full-Text Articles in Engineering
Analysis Of Square-Root Kalman Filters For Angles-Only Orbital Navigation And The Effects Of Sensor Accuracy On State Observability, Jason Knudsen Schmidt
Analysis Of Square-Root Kalman Filters For Angles-Only Orbital Navigation And The Effects Of Sensor Accuracy On State Observability, Jason Knudsen Schmidt
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Angles-only navigation is simple, robust, and well proven in many applications. However, it is sometimes ill-conditioned for orbital rendezvous and proximity operations because, without a direct range measurement, the distance to approaching satellites must be estimated by firing thrusters and observing the change in the target's bearing. Nevertheless, the simplicity of angles-only navigation gives it great appeal. The viability of this technique for relative navigation is examined by building a high-fidelity simulation and evaluating the sensitivity of the system to sensor errors. The relative performances of square-root filtering methods, including Potter, Carlson, and UD factorization filters, are compared to the …
An Exploration Of Formal Methods And Tools Applied To A Small Satellite Software System, Russell J. Grover
An Exploration Of Formal Methods And Tools Applied To A Small Satellite Software System, Russell J. Grover
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Formal system modeling has been a topic of interest in the research community for many years. Modeling a system helps engineers understand it better and enables them to check different aspects of it to ensure that there is no undesired or unexpected behavior and that it does what it was designed to do. This thesis takes two existing tools that were created to aid in the designing of spacecraft systems and creates a layer to connect them together and allow them to be used jointly. The first tool is a library of formal descriptions used to specify spacecraft behavior in …
Guidance And Navigation Linear Covariance Analysis For Lunar Powered Descent, Travis J. Moesser
Guidance And Navigation Linear Covariance Analysis For Lunar Powered Descent, Travis J. Moesser
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A linear covariance analysis is conducted to assess closed-loop guidance, navigation, and control system (GN&C) performance of the Altair vehicle during lunar powered descent. Guidance algorithms designed for lunar landing are presented and incorporated into the closed-loop covariance equations. Navigation-based event triggering is also included in the covariance formulation to trigger maneuvers and control dispersions. Several navigation and guidance trade studies are presented demonstrating the influence of triggering and guidance and study parameters on the vehicle GN&C performance.