|
Description:
|
The objective of this research is to study different novel developed techniques for spacecraft attitude determination methods using star tracker sensors . This dissertation addresses various issues on developing improved star
tracker software , presents new approaches for better performance of star trackers , and
considers applications to realize high precision attitude estimates .
Star -sensors are often included in a spacecraft attitude -system instrument suite , where
high accuracy pointing capability is required . Novel methods for image processing , camera
parameters ground calibration , autonomous star pattern recognition , and recursive star
identification are researched and implemented to achieve high accuracy and a high frame
rate star tracker that can be used for many space missions . This dissertation presents
the methods and algorithms implemented for the one Field of View 'FOV' StarNavI sensor
that was tested aboard the STS -107 mission in spring 2003 and the two fields of view
StarNavII sensor for the EO -3 spacecraft scheduled for launch in 2007 . The results of
this research enable advances in spacecraft attitude determination based upon real time
star sensing and pattern recognition . Building upon recent developments in image
processing , pattern recognition algorithms , focal plane detectors , electro -optics , and
microprocessors , the star tracker concept utilized in this research has the following key
objectives for spacecraft of the future : lower cost , lower mass and smaller volume ,
increased robustness to environment -induced aging and instrument response variations ,
increased adaptability and autonomy via recursive self -calibration and health -monitoring
on -orbit . Many of these attributes are consequences of improved algorithms that are
derived in this dissertation . |