Thesis (MScEng)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The primary payload of the University of Stellenbosch's micro-satellite, SUNSAT I,
was a high quality imager, capable of taking stereoscopic images of the surface of
the earth. Although the orbit of SUNSAT I will have the satellite pass over the whole
earth, contact via the SUNSAT I ground station at the University will only be made for
3% of each day. To be able to photograph any part of the earth onboard memory
was provided on the satellite to store the image until it can be downloaded to the
ground station. A high speed downlink was also added to the satellite to be able to
download a complete image from the onboard memory in one pass and also to take
realtime pictures as the satellite passes over the ground station. At that stage there
was no way to capture the data at the ground station. A high speed digital data
capture mechanism was needed. The thesis discusses the development of a high
speed capture card.
Due to the high speeds needed it provided an excellent opportunity to develop the
card using the PCI bus, the first design to do so at the University, as an interface with
a computer. A prototype card was developed first to do proof of concept. It is shown
that the prototype card fulfilled the functional requirements and it was also used to
capture the first image from the complete satellite during the final tests before launch.
Finally a production card for use in the ground station was designed and assembled. / AFRIKAANSE OPSOMMING: Die hoof loonvrag van die Universtieit van Stellenbosch se eerste mikrosatelliet,
SUNSAT I, is "n hoë kwaliteit kamera wat stereoskopiese fotos van die oppervlak van
die aarde kan neem. Alhoewel die satelliet oor die hele oppervlakte van die aarde
gaan beweeg, is dit vir slegs 3% van die dag sigbaar vanaf die grondstasie by die
Universiteit van Stellenbosch. Om 'n foto van enige plek op aarde te kan neem is
daar aanboord geheue op die satelliet geplaas om die foto te stoor totdat dit by die
grondsatsie afgelaai kan word. "n Hoë spoed skakel is ook daargestelom die data
in die geheue van die satelliet in een verbyvlug te kan aflaai. Dit stel die satelliet ook
in staat om intydse fotos gedurende In verbyvlug van die satelliet te kan neem. Op
daardie stadium het daar nog nie "n manier bestaan om die hoë spoed data vas te
lê nie. In Meganisme om die hoë spoed digitale data te vang was nodig. Hierdie
tesis bespreek die ontwikkeling van so In data vang kaart.
Weens die hoë snelhede wat benodig word, het die PCI bus die ideale oplossing
gebied om die data teen "n hoë spoed op In persoonlike rekenaar te stoor. Dit was
ook die eerste ontwerp aan die Universiteit wat van die PCI bus gebruik gemaak het.
In die eerste instansie is In prototipe ontwikkel om te bewys dat dit wel moontlik is om
die data teen die benodigde tempo te kan stoor. Daar word gewys dat die prototipe
aan die behoefte voldoen en dit is ook gebruik om die eerste beeld vanaf die
volledige satelliet te vang voordat dit gelanseer is.
In die tweede instansie word In produksiekaart ontwikkel en aanmekaar gesit.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52763 |
| Date | 03 1900 |
| Creators | Van der Westhuizen, W. J. (Willem Joseas) |
| Contributors | Bakkes, P. J., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 201 p. : ill. |
| Rights | Stellenbosch University |
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