A thesis submitted to the Faculty of Science
in fulfillment of the requirements of the degree of
Doctor of Philosophy
School of Computational and Applied Mathematics
University of the Witwatersrand
September 20, 2012 / In this thesis, we analyse reasons for poor image quality on the Southern
African Large Telescope (SALT) and we analyse control methods of the
segmented primary mirror. Errors in the control algorithm of SALT (circa
2007) are discovered. More powerful numerical procedures are developed
and in particular, we show that singular value decomposition method is preferred
over normal equations method as used on SALT. In addition, this
method does not require physical constraints to some mirror parameters.
Sufficiently accurate numerical procedures impose constraints on the precision
of segment actuator displacements and edge sensors. We analyse the
data filtering method on SALT and find that it is inadequate for control.
We give a filtering method that achieves improved control. Finally, we give
a new method (gradient flow) that gives acceptable control from arbitrary,
imprecise initial alignment.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/12677 |
| Date | 23 April 2013 |
| Creators | Kamga, Morgan M. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf, application/pdf, application/pdf, application/pdf |
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