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Full-Text Articles in Engineering
Autonomous Mission Planning For Spacecraft Rendezvous And Proximity Operations, Julia C. Bell
Autonomous Mission Planning For Spacecraft Rendezvous And Proximity Operations, Julia C. Bell
Theses and Dissertations
The evolving space environment has created a demand for autonomous spacecraft that can maneuver in complex and sometimes contentious environments. Constraint enforcement, such as an avoidance zone to prevent collision with a target, is a key component of autonomous control to ensure safety and performance requirements are met. Finite-horizon Model Predictive Control (MPC) is a popular control method due to its improved computation time while optimizing performance. Two areas of MPC in need of expansion are time-varying constraints and phase transitions in multi-phase applications. In this work, MPC is employed to track the reference trajectory of a multi-phase satellite inspection …
Space-Based Localization Of Radio Frequency Transmitters Utilizing Macaulay Resultant And Heuristic Optimization Methods, Jessica M. Wightman
Space-Based Localization Of Radio Frequency Transmitters Utilizing Macaulay Resultant And Heuristic Optimization Methods, Jessica M. Wightman
Theses and Dissertations
This research focuses on radio frequency geolocation of space objects utilizing space-based platforms. Geolocation has long been the solution for locating objects. In particular, this study examines the scenario of two cooperative receivers geolocating a transmitter in close proximity. An algorithm is developed to calculate the initial estimated transmitter location and projected orbital trajectory. The algorithm uses the Macaulay method of solving a system of polynomials as well as heuristic optimization techniques to locate a transmitter with respect to receivers at different time intervals. For the scenarios investigated, both Macaulay and heuristic optimization methods achieve initial relative orbit determination.