| dc.description.abstract | This research analyzes and demonstrates the local position determination problem
on Earth using a novel instrument, the Compass Star Tracker. Special focus is
given to the theoretical development of the mathematics of local position determination,
the design and fabrication of a proof-of-concept instrument, an error source
analysis, and the experimental tests used to validate the position determination concepts.
Star sensors are typically used as attitude determination instruments on spacecraft
orbiting Earth. In this capacity, the star sensor determines the orientation of
the spacecraft using digital images of the stars. This research utilizes the basic functionality
of the star sensor in a new way; the orientation information from the star
image is used to determine a user's latitude and longitude coordinates on Earth. This
concept is valuable because it allows users to determine their position autonomously.
The fundamental concepts that enable local position determination were originally
published in Drs. Samaan, Mortari, and Junkins (AAS 04-007). This research
improves upon that work by eliminating the zenith-orientation constraint and providing
several crucial theoretical corrections. In addition to the position determination
mathematics, this research provides analysis of the theoretical and practical error
sources associated with the position determination problem. This research also details
the design, fabrication, and experimental test program of a proof-of-concept Compass Star Tracker. Together, the theoretical development, error analysis, instrument
design, and test program serve as validation of the the position determination
concept. This work is intended as the first of many steps toward eventual deployment
of autonomous position determination sensors on the Moon and Mars. | en |
