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The development and implementation of a localised position location strategySchonken, Willem Petrus Francois 12 1900 (has links)
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Location and tracking of personnel and assets is a lucrative enterprise that has seen much expansion in
the last decade or two. This expansion is coupled with the rise in popularity of GPS-based technologies.
It has become common practice for businesses to track and manage vehicle fleets with GPS enabled
devices. We use GPS to navigate while driving our cars, to keep track of our loved ones and we even
have GPS receivers in our cell phones.
Unfortunately, GPS technology has a few limitations. It can only be used in areas with a clear view of the
sky, as line-of-sight must be maintained with at least four satellites at all times. This precludes the use of
GPS indoors or in heavily built-up areas. GPS receivers are also still quite expensive.
This thesis developed and implemented a strategy for Localised Position Location. Several possible
solutions were investigated. Spread Spectrum was selected as the best method to develop into a
working example. The characteristics of Spread Spectrum signals and Pseudo-Noise Codes were
investigated in some detail, which led to the proposal of several simulation models. These simulations
suggested that a simple configuration consisting of a transmitter, sliding correlator, bandpass filter and
RF power detector can effectively track a stationary target.
A transmitter was designed and implemented and was then used in a simplified measurement to
corroborate the predictions made by earlier simulations. With results looking positive it was decided to
continue with the design and implementation of a receiver. A complete transmitter/receiver system
allowed for extensive measurements to be made. The physical measurements agreed with simulated
predictions, confirming that the proposed position location strategy is effective. / AFRIKAANSE OPSOMMING: Die toenemende gewildheid en toeganklikheid van GPS-gebaseerde opsporingstegnologie het gelei tot
‘n geweldige toename in die verkope van toerusting om die beweging van besigheidsbates te monitor en
bestuur. Selfs op die persoonlike ontspanningsmark vind GPS-tegnologie toenemend aanklank met
vervaardigers van selfone en voertuignavigasietoerusting.
GPS-gebaseerde opsporingstegnologie het egter beperkinge, omdat dit te alle tye direkte oogkontak
moet behou met minstens vier satelliete. Gevolglik kan GPS-gebaseerde opsporingstegnologie nie
binnenshuis of in erg beboude gebiede gebruik word nie. GPS ontvangers is ook redelik duur.
Hierdie thesis het `n strategie vir Gelokaliseerde Posisie Bepaling ontwikkel en geïmplementeer.
Ondersoek is ingestel na `n verskeidenheid van moontlike oplossings. Strek Spektrum is gekies as die
beste metode om verder in `n werkende voorbeeld te ontwikkel. Die eienskappe van Strek Spektrum
seine en Pseudo-Ruis Kodes is in detail bestudeer, wat gelei het na die opstelling van `n aantal simulasie
modelle. Hierdie modelle dui aan dat `n eenvoudige opstelling, bestaande uit `n sender, glykorellator,
banddeurlaat filter en `n RF drywingsmeter doeltreffend aangewend kan word om `n stilstaande teiken
te monitor.
`n Sender, wat in `n vereenvoudigde meetopstelling gebruik kon word om van die voorspellings wat
vroeër gemaak is te staaf, is hierna ontwerp en gebou. Met positiewe resultate is daar besluit om voort
te gaan met die ontwerp en bou van `n ontvanger. Met `n volledige sender/onvanger stelsel was dit
moontlik om uitgebreide meetings te neem. Die fisiese meetings stem ooreen met die simulasies se
voorspellings, wat dien as bevestiging dat die voorgestelde strategie vir posisie bepaling doeltreffend
aangewend kan word.
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