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Processing of onboard images to assist automatic forward motion compensation for micro-satellites

Thesis (MScEng)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: South Africa's first micro satellite, SUNSAT, was operational in orbit for 23 months
since its NASA-sponsored launch on February 23, 1999. SUNSAT is a graduate studentdeveloped
satellite from the University of Stellenbosch in South Africa. Research work is
in progress on improving SUNSAT's 15m multi-spectral imager to a 2.5m-resolution
multi-sensor imager. This will require the use of Forward Motion Compensation for
exposure control.
This thesis presents Automatic Forward Motion Compensation for Micro Satellites using
a new earth sensor that measures the bore-sight projection's speed on the earth directly.
This sensor will have no drift and will make use of a series of images and crosscorrelation
of them. The high-resolution imager's bore-sight motion can be controlled by
this technique to ensure high quality stereo images.
A control system based on the DLR-TUBSAT was designed and is simulated in
MATLAB. This technique of measuring the bore-sight projection's speed on the earth
directly was tested on a 2-axis telescope and used to measure random movement of a
satellite. / AFRIKAANSE OPSOMMING: SUNSAT, Suid Afrika se eerste satelliet was vir 23 maande in werking in 'n wentelbaan
na sy NASA-geborgde lasering op 23 Februarie 1999. SUNSAT is 'n satelliet wat
ontwikkel is deur nagraadse studente aan die Universiteit van Stellenbosch.
Navorsingswerk is aan die gang om SUNSAT se 15m resolusie multi-spektrale kamera te
verbeter tot 'n 2.5m resolusie multi-sensor kamera. Die navorsing sal die gebruik van
Voorwaartse Bewegingskompensasie benodig.
Die tesis handeloor automatiese voorwaartse bewegingskompensasie vir mikrosatelliete
deur gebruik te maak van 'n nuwe aardgerigte sensor, wat die siglyn projeksie se snelheid
op die aarde direk sal meet. Die sensor sal gebruik maak van 'n reeks foto's wat
gekruiskorreleer word en sal geen tempo-wegdrywing hê nie. Hoë resolusie kameras se
siglyn kan deur middel van hierdie tegniek beheer word om hoë kwaliteit stereo foto's te
verseker.
'n Beheerstelsel wat gebaseer is op dié van DLR-TUBSAT, is ontwerp en is gesimuleer
in MATLAB. Die tegniek om die siglyn projeksie se snelheid op die aarde direk te meet,
is getoets op 'n 2-as teleskoop en is gebruik om onverwille keurige beweging van 'n
satelliet te meet.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/53559
Date03 1900
CreatorsMouton, Christiaan J.
ContributorsSchoonwinkel, A., Milne, G. W., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering.
PublisherStellenbosch : Stellenbosch University
Source SetsSouth African National ETD Portal
Languageen_ZA
Detected LanguageEnglish
TypeThesis
Format103 p. : ill.
RightsStellenbosch University

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