Garry L. Hall

Date of Award


Document Type


Degree Name

Master of Science in Astronautical Engineering


Department of Aeronautics and Astronautics


This study investigated the use of a least squares differential corrector to compress the information contained in a single radar track of a Near Earth satellite into a six element, Earth Centered Inertial state vector and associated covariance matrix. Observations were generated using a truth model program based on two body, J2 geopotential, and atmospheric drag dynamics and consisted of simulated range, azimuth and elevation. Random Gaussian noise was added to the data to simulate real world random errors. The orbital dynamics used in the estimator consisted of two body and J2 geopotential effects which were approximated using a Taylor Series expansion in time. Analysis was conducted using two circular, inclined low earth orbits. Estimator performance was evaluated as a function of maximum pass elevation, track duration, data rate and the order of approximation of the equations of state. The estimator successfully extracted all of the pertinent information from the data with accuracy being dependent on the number of data points available. A correlation between the required order of approximation and maximum expected track length was also noted.

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Astrodynamics Commons