Date of Award
Master of Science in Astronautical Engineering
Department of Aeronautics and Astronautics
Nathan Titus, PhD
A technique is developed to determine the orbit of a sunlight illuminated satellite passing through the field-of-view of a sensor platform in a Highly Elliptical Orbit (HEO) and Geosynchronous orbit (GEO). The technique develops two different methods of initial orbit determination. The first relies on the Gauss initial orbit determination method to develop an estimate of the state from angular data. The second method relies on positional data of the target relative to the Earth’s background to determine an estimate of the state. These estimates are then refined in a non-linear least squares routine. This estimate of the state is then used to identify the target from the Air Force Space Command satellite catalog. It was found that the Gaussian initial orbit determination method produced reasonable estimates of the state given data sets larger than 30 seconds. The second method proved to be useful when only very limited data sets were available and had no limitations on data size. The least squares process was able to compensate for errors of as much as 5 degrees in the initial estimate of the state values. In all HEO test cases the estimate of the state vector provided enough information to identify the target satellite from the satellite catalog. In GEO test cases it proved impossible to identify other objects in GEO given the limited data available. The method developed also proved unreliable in identifying orbits with eccentricities greater than .35. Over 82 percent of the objects listed in the Air Force Space Command satellite catalog can be successfully identified in orbit using this method.
DTIC Accession Number
Townsend, Bradley R., "Space Based Satellite Tracking and Characterization Utilizing Non-Imaging Passive Sensors" (2008). Theses and Dissertations. 2701.