Onboard image geo-referencing for LEO satellites
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2005.
The next generation of small satellites will require significant onboard data processing and information extraction capabilities to keep up with industry demands. The need for value added information products is growing as accessibility and user education is improving. Image geo-referencing is one of the image processing steps needed to transform raw images into usable information. Automating this process would result in a vast improvement in processing time and cost. As part of the background study, the imaging process is described and a model of the process is created. The sources of distortion that are present in the imaging process are described and techniques to compensate for them are discussed. One method that stands out is using wavelet analysis for the precision geo- referencing of images. Wavelets are used in this thesis for automatic ground control point identification. Finally, the automatic ground control point algorithm is used for band-alignment of a set of aerial images at sub pixel accuracy as a demonstration of the quality of ground control points that can be found.