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Full-Text Articles in Astrodynamics
Limitations Of Initial Orbit Determination Methods For Low Earth Orbit Cubesats With Short Arc Orbital Passes, James P. Johnson
Limitations Of Initial Orbit Determination Methods For Low Earth Orbit Cubesats With Short Arc Orbital Passes, James P. Johnson
Master's Theses
This thesis will focus on the performance of angles only initial orbit determi- nation (IOD) methods on observational data of low Earth orbit (LEO) CubeSats. Using data obtained by Lockheed Martin’s Space Object Tracking (SpOT) facil- ity, four methods: Gauss, Double-R, Gooding and Assumed Circular, will use different amounts of orbital arc to determine which methods perform the best in the short arc regime of less than 10 degrees of orbital arc. Once the best method for estimating the orbit is determined, there will be analysis on whether these IOD methods are accurate enough to predict a secondary observation session. …
Attitude Estimation For A Gravity Gradient Momentum Biased Nanosatellite, Arash Mehrparvar
Attitude Estimation For A Gravity Gradient Momentum Biased Nanosatellite, Arash Mehrparvar
Master's Theses
Attitude determination and estimation algorithms are developed and implemented in simulation for the Exocube satellite currently under development by PolySat at Cal Poly. A mission requirement of ±5˚ of attitude knowledge has been flowed down from the NASA Goddard developed payload, and this requirement is to be met with a basic sensor suite and the appropriate algorithms. The algorithms selected in this work are TRIAD and an Extended Kalman Filter, both of which are placed in a simulation structure along with models for orbit propagation, spacecraft kinematics and dynamics, and sensor and reference vector models. Errors inherent from sensors, orbit …