Recent studies have demonstrated that images constructed from lidar reflectance information exhibit superior robustness to lighting changes. However, due to the scanning nature of the lidar and assumptions made in previous implementations, data acquired during continuous vehicle motion suffer from geometric motion distortion and can subsequently result in poor metric visual odometry (VO) estimates, even over short distances (e.g., 5-10 m). The first part of this thesis revisits the measurement timing assumption made in previous systems, and proposes a frame-to-frame VO estimation framework based on a pose-interpolation scheme that explicitly accounts for the exact acquisition time of each intrinsic, geometric feature measurement. The second part of this thesis investigates a novel method of lidar calibration that can be applied without consideration of the internal structure of the sensor. Both methods are validated using experimental data collected from a planetary analogue environment with a real scanning laser rangefinder.

According to Chapter XV of the Chicago Convention, the Joint Financing Aid has been successfully applied in the North Atlantic Region since 1948. The Agreement on the Joint Financing of Certain Air Navigation Services in Iceland, the main topic of this thesis, has ensured the availability of the service and facilities in the Reykjavik Flight Information Region, in accordance with the Standards and recommended practices of the Annexes to the Chicago Convention. The services were at first financed by the participating States, but later on user charges were gradually introduced and, since 1981, they became the principal means of services financing. / During the last thirty years, a series of significant social, economic and technical developments has changed the aviation and the air navigation services environment. This thesis examines the evolution of the Agreement and the general technical and economic tendencies that are likely to affect its future. / This thesis critically examines the Agreement in light of ICAO policy on the joint support aid and the general economic situation surrounding the Agreement. (Abstract shortened by UMI.)

Do we always have to be lost in the halls of a big school on an already stressful first day of class? This paper has evaluated a prototype indoor navigation system that uses a ANT wireless protocol. The protocol has been placed into nodes (small electrical devices, hardware) which are then placed around an area of interest (a map), like beacons, using RSSI (signal from the nodes) to help determine where the subject is located. The mobile application is made specific to Android with a search algorithm that is based off of vector analysis with weighted percentages. The idea being that if the position of each node is available, knowing the location between the nodes should be easily achievable. The nodes were build successfully along with an android application to verify each nodes functionally and see the nodes RSSI values. The algorithm works as expected but due to several factors was not able to be fully realized. In the actual test the system results where slow and did not update in real time. It was found that the ANT protocol does not have a fast packet reception when using the continuous scan feature made available by ANT. The results of the search algorithm were not good enough for a real time indoor navigation prototype. The search algorithm was slow. The system needs more inputs to accurately locate a subject indoors.

Electronic documents form an integral part of the modern computer age---virtually all personal computers have the ability to create, store and display their content. A connection to the Internet provides users with an almost endless source of documents, be they web-pages, word-processor files or emails. However, the entire contents of an electronic document are often too large to be usefully presented on a user’s screen, at a single point in time. This issue is usually overcome by placing the content inside a scrolling environment. The view onto the document is then modified by directly adjusting a scrollbar or by employing tools such as the mousewheel or paging keys. Applications may also provide methods for adjusting the document’s zoom and page layout. The scrollbar has seen widespread adoption, becoming the default tool used to visualise large information spaces. Despite its extensive deployment, researchers have little knowledge on how this and related navigation tools are used in an everyday work environment. A characterisation of users’ actions would allow designers to identify common behaviours and areas of inefficiency as they strive to improve navigation techniques. To fill this knowledge gap, this thesis aims to understand and improve navigation within desktop-based electronic documents. This goal is achieved using a five step process. First, the literature is used to explore document navigation tasks and the tools currently available to support electronic document navigation. Second, a software tool called AppMonitor, that logs users’ navigation actions, was developed. Third, AppMonitor was deployed in a longitudinal study to characterise document navigation actions in Microsoft Word and Adobe Reader. Forth, to compliment this study, two task-centric observations of electronic document navigation were performed, to probe the reasons for navigation tool selection. Finally, the Footprints Scrollbar was developed to improve one common aspect of navigation—within-document revisitation. To begin, two areas of current knowledge in this domain are overviewed: paper and electronic document navigation and electronic document navigation tools. The literature review produced five categories of document navigation tasks: ‘overviewing and browsing’, ‘reading’, ‘annotating and writing’, ‘searching’ and ‘revisitation’. In a similar fashion, electronic document navigation tools were reviewed and divided into eight categories: core navigation tools (those commonly found in today’s navigation systems), input devices, scrollbar augmentations, content-aware navigation aids, visualisations that provide multiple document views, indirect manipulation techniques, zooming tools and revisitation tools. The literature lacked evidence of an understanding of how these current document navigation tools are used. To aid the gathering of empirical data on tool use, the AppMonitor tool was developed. It records user actions in unmodified Windows applications—specifically for this research, Microsoft Word and Adobe Reader. It logs low-level interactions such as “left mouse button pressed” and “Ctrl-f pressed” as well as high level ‘logical’ actions such as menu selections and scrollbar manipulations. It requires no user input to perform these tasks, allowing study participants to continue with their everyday work. To collect data to form a characterisation of document navigation actions, 14 participants installed AppMonitor on their computer for 120 days. This study found that users primarily employ the mousewheel, scrollbar thumb and paging keys for navigation. Further, many advanced navigation tools that are lauded for their efficiency, including bookmarks and search tools, are rarely used. The longitudinal study provided valuable insights into the use of navigation tools. To understand the reasons behind this tool use, two task-centric observations of electronic document navigation were conducted. The first asked participants to perform a series of specific navigation tasks while AppMonitor logged their actions. The second was performed as a series of interactive sessions, where users performed a particular task and were then probed on their tool choice. These two studies found that many users are not aware of the advanced navigation tools that could significantly improve their navigation efficiency. Finally, the characterisations highlighted within-document revisitation as a commonly performed task, with current tools that support this action rarely used. To address this problem, the analysis, design and evaluation of a Footprints Scrollbar is presented. It places marks inside the scrollbar trough and provides shortcuts to aid users return to previously visited locations. The Footprints Scrollbar was significantly faster and subjectively preferred over a standard scrollbar for revisitation tasks. To summarise, this thesis contributes a literature review of document navigation and electronic document navigation tools; the design and implementation of AppMonitor—a tool to monitor user actions in unmodified Windows applications; a longitudinal study describing the navigation actions users perform; two taskcentric studies examining why actions are performed; and the Footprints Scrollbar, a tool to aid within-document revisitation tasks.

This research focuses on the development of a persistent navigation algorithm for a hovering vehicle with a single, downward-facing visible spectrum camera. A successful persistent navigation algorithm allows a vehicle to: * Continuously estimate its location and pose within a local, if not global, coordinate frame. * Continuously align incoming data to both temporally proximal and temporally distant data. For aerial images, this alignment is equivalent to image mosaicking, as is commonly used in aerial photogrammetry to produce broad-scale photomaps from a sequence of discrete images. * Operate relative to, and be commanded relative to the sensor data, rather than relative to an abstract coordinate system. The core application space considered here is moderate-to-high altitude aerial mapping, and a number of sets of high-resolution, high-overlap aerial photographs are used as the core test data set. These images are captured from a sufficient altitude that the apparent perspective shift of objects on the ground is minimized -- the scene is effectively planar. As such, this research focuses heavily on the properties and advantages available when processing such planar images. This research is split into two threads which track the two main challenges in visual persistent navigation: the association and alignment of visual data given significant image change, and the development of an estimation algorithm and data storage structure with bounded computational and storage costs for a fixed map size. Persistent navigation requires the robot to accurately align incoming images against historical data. By its nature, however, visual data contains a high degree of variability despite minimal changes in the scene itself. As a simple example, as the sun moves and weather conditions change, the apparent illumination and shading of objects in the scene can vary significantly. More critically, image alignment must be robust to change in the scene itself, as that change is often a critical output from the robot's re-exploration. This problem is considered in two contexts. First, a set of state-of-the-art feature detection algorithms are evaluated against sample data sets which include both temporally proximal and disparate images of the same location. The capacity of each algorithm to identify repeated point features is measured for a spectrum of algorithm-specific parameter values. Next, the potential of using a prior estimate on the inter-image geometry to improve the robustness of precise image alignment is considered for two phases of the image alignment process: feature matching and robust outlier rejection. A number of geometry-aware algorithms are proposed for both phases, and tested against similar sets of similar and disparate aerial images. While many of the proposed algorithms do improve on the performance of the unguided algorithms, none are vastly superior. The second thread starts by considering the problem of navigation fromdownward-looking aerial images from the perspective of Simultaneous Localization and Mapping (SLAM). This leads to the development of Simultaneous Mosaicking and Resectioning Through Planar Image Graphs (SMARTPIG), an online, iterative mosaicking and SLAM algorithm built on the assumption of a planar scene. A number of samples of SMARTPIG outputs are shown, including mosaics of a 600-meter square airport with approximately 3-meter reprojection errors relative to ground control points. SMARTPIG, like most SLAM algorithms, does not fulfill the criteria for persistent navigation because the computational and storage costs are proportional to the total mission length, not the total area explored. SMARTPIG is evolved towards persistent navigation by the introduction of the featurescape, a storage structure for long-term point-feature data, to produce Planar Image Graphs for PErsistent Navigation (PIGPEN). PIGPEN is demonstrated perfoming robot re-localization onto an existing SMARTPIG mosaic with an accuracy comparable to the original mosaic.

The North American crab spider Misumenoides formosipes is a sit-and-wait predator of insect pollinators. Females are relatively sedentary and adult males must search for females within a heterogeneous habitat. Females are receptive to mating immediately after their adult molt and a first sperm priority pattern places a premium on male ability to locate females quickly. It is unknown what cues males use to navigate during searches for females. We report here on the male-biased operational sex ratio, the distances traveled and the possible cues utilized by moving males. Males in field trials moved towards inflorescences when both visual and chemical cues were available, but were less likely to do so when chemical cues were eliminated. Males in lab trials chose an inflorescence over leaf substrates even in the absence of visual cues. These findings support the hypothesis that these spiders utilize floral chemistry as an environmental cue to optimize mate searches. / Department of Biology

Det blir allt mer vanligt att människor kopplar upp sig mot internet via sin smartphone, både privat och i arbetet. Detta innebär att webbsidor måste anpassas för att visas i dessa enheter. Men att mobilanpassa en webbsida kan vara svårt när det kommer till överskådlighet och navigation av webbsidan. Detta på grund av den begränsade skärmytan. När det kommer till att mobilanpassa en webbsida talas det ofta om två tekniker, responsiv webbdesign och mobila webbapplikationer. Det är dessa två tekniker som diskuteras och jämförs i denna kandidatuppsats. Netgain är ett företag som just nu står inför valet av teknik och detta fall används som exempel för att visa på hur resultatet från denna kandidatuppsats kan relateras till ett specifikt fall i praktiken. Syftet med denna kandidatuppsats i informatik är att göra en jämförelse mellan teknikerna responsiv webbdesign och mobil webbapplikation. Uppsatsen syftar till att beskriva vilka faktorer som kan påverka valet av teknik när det gäller navigation och överskådlighet i smartphones med fokus på användning. Uppsatsen syftar även till att visa hur dessa faktorer kan relateras till ett företag som Netgain. Frågan är hur dessa faktorer kan användas för att ta fram rekommendationer avseende vilken av teknikerna responsiv webbdesign och mobil webbapplikation som passar bäst för en mobil representation av deras affärsmodell för IT. I denna undersökning har ett kvalitativt angreppssätt tillämpats bestående av en fallstudie som har baserats på personliga intervjuer med konsulter på ett webbföretag. Utifrån dessa intervjuer, tillsammans med insamlad teori, har faktorer som kan påverka valet av teknik när det gäller navigation och överskådlighet i smartphones identifierats. Det tydligaste resultatet som framkom i denna undersökning är att mängden information, som ska finnas på den mobilanpassade webbsidan, kan påverka valet av teknik. Vid stora informationsmängder och djupa informationsstrukturer har en mobil webbapplikation en fördel framför responsiv webbdesign. Däremot tillgodoser responsiv webbdesign användarens förväntning om att det som går att finna på en webbsida som visas på en desktop även ska gå att finna i en smartphone. I en mobil webbapplikation finns möjligheten att styra innehållet på ett annat sätt än vid responsiv webbdesign. Detta gör att en mobil webbapplikation har en fördel även när det kommer till överskådlighet och detta kan även bidra till att användaren kan nå sitt mål snabbare än på en webbsida utvecklad med responsiv webbdesign. Undersökningen visade vidare att när det kommer till att göra en mobilanpassad webbsida överskådlig samt enkel att navigera för alla användare, oavsett behov, har en mobil webbapplikation även här en fördel framför responsiv webbdesign. Detta på grund av att det vid responsiv webbdesign kan vara svårt att få innehållet på webbsidan att läsas upp korrekt av en skärmläsare. Dock har responsiv webbdesign en fördel i att denna teknik tillhandahåller ett minimalt behov av att zooma innehållet. Nyckelord: responsiv webbdesign, mobil webbapplikation, navigation, mobil webb.

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This research effort is concerned with the methods of simplified orbit determination and orbit representation and their applications for Low Earth Orbit (LEO) satellite missions, particularly addressing the operational needs of the FedSat mission. FedSat is the first Australian-built satellite in over thirty years. The microsatellite is approximately 50cm cubed with a mass of 58 kg. The satellite was successfully placed into a low-earth near-polar orbit at an altitude of 780km by the Japanese National Space Development Agency (NASDA) H-IIA launch vehicle on 14, December 2002. Since then, it has been streaming scientific data to its ground station in Adelaide almost daily. This information is used by Australian and international researchers to study space weather, to help improve the design of space computers, communication systems and other satellite technology, and for research into navigation and satellite tracking. This research effort addresses four practical issues regarding the FedSat mission and operations. First, unlike most satellite missions, the GPS receiver onboard FedSat operates in a duty-cycle mode due to the limitations of the FedSat power supply. This causes significant difficulties for orbit tracking, Precise Orbit Determination and scientific applications. A covariance analysis was performed before the mission launch to assess the orbit performance under different operational modes. The thesis presents the analysis methods and results. Second, FedSat supports Ka-band tracking experiments that require a pointing accuracy of 0.03 degree. The QUT GPS group is obligated to provide the GPS precise orbit solution to meet this requirement. Ka-band tracking requests satellite orbital position at any instant time with respect to any of the observation stations. Because orbit determination and prediction software only provide satellite orbital data at a discrete time point, it is necessary to find a way to represent the satellite orbit as a continuous trajectory with discrete observation data, able to obtain the position of the satellite at the time of interest. For this purpose, an orbit interpolation algorithm using the Chebyshev polynomial was developed and applied to Ka-band tracking applications. The thesis will describe the software and results. Third, since the launch of FedSat, investigators have received much flight GPS data. Some research was invested in the analysis of FedSat orbit performance, GPS data quality and the quality of the onboard navigation solutions. Studies have revealed that there are many gross errors in the FedSat onboard navigation solution (ONS). Although the 1-sigma accuracy of each component is about 20 m, there are more than 11 %positioning errors that fall outside +/-50m, and 5% of the errors are outside the 100mbound. The 3D RMS values would be 35m, 87m, and 173m for the above three cases respectively. The FedSat ONS uncertainties are believed to be approximately three times greater than those from other satellite missions. Due to the high percentage of outlier solutions, it would be dangerous to use these without first applying data detection and exclusion procedures. Therefore, this thesis presents two simplified orbit determination methods that can improve the ONS. One is the &quotgeometric method", which makes use of delta-position solutions derived from carrier phase differences between two epochs to smooth the code-based navigation solutions. The algorithms were tested using SAC-C GPS data and showing some improvement. The second method is the &quotdynamic method", which uses orbit dynamics information for orbit improvements. Fourth, the FedSat ground tracking team at Adelaide use the NORAD TLE orbit for daily FedSat tracking. Research was undertaken to convert an orbit trajectory into these Two Line Elements (TLE). Algorithms for the estimation of TLE solutions from the FedSat onboard GPS navigation solutions are outlined. Numerical results have shown the effects of the unmodelled forces/perturbations in the SPG4 models for the FedSat orbit determination would reach a level of ±1000m. This only includes the orbit representation errors with TLE data sets. The total FedSat orbit propagation should include both the orbit propagation and orbit representation terms. The analysis also demonstrates that the orbit presentation error can be reduced to ±200m and ±100mlevels with the EGM4x4 and EGM10x10 gravity field models respectively. This can meet the requirements for Ka-band tracking. However, a simplified tracking program based on numerical integration has to be developed to replace the SPG4 models.

This thesis concerns the life-histories of the two contemporary Polynesian vovaging canoes from Aotearoa New Zealand. It documents the background, construction and voyages of Hawaiki Nui (1979 - 1986) built by Matahi Whakataka-Brightwell and Te Aurere (1992 - 1998) built by Hekenukumai Puhipi Busby. It also highlights the historical and cultural significance of waka for Maori and other indigenous Pacific peoples. Based on my field work as a participant in Maori voyaging between 1996 and 1998, I argue that this revival of waka voyaging reaffirms the cultural identities of contemporary Maori and other Polynesians. The case studies of Hawaiki Nui and Te Aurere confirm the ongoing significance of waka not only in Aotearoa New Zealand, but Pacific-wide. Contemporary Polynesian waka voyaging is historically significant as it revives unique Polynesian skills, such as traditional waka-building, navigation and sailing techniques. It is also culturally significant, as it reinforces central Maori (and Polynesian) cultural concepts, such as whakapapa (genealogy ties) and whanaungatanga (sense of belonging). At a time when Maori(as well as other indigenous Pacific peoples) are constantly negotiating and redefining their cultural boundaries within their respective socio-political contexts, Polynesian voyaging waka are reappearing as a strong symbol of Pacific Islanders� cultural identities. As a symbol of a shared seafaring past they create timeless platforms for Maori and other Polynesians to negotiate the boundaries of their cultures.