Airborne Laser Scanning is an advanced surveying technology (also called Light Detection and Ranging - LIDAR) which mounts a laser scanner on an aircraft. The aircraft scans the Earth's surface and captures data by emitting and receiving light pulses transmitted onto the terrain objects. The captured data are in three dimensions (3D); however no extra information is provided to describe them. Additional algorithms are needed to extract meaningful and useful information from the data. The popularity of LIDAR has attracted attention as researchers try to develop algorithms for 3D building reconstruction in Geographical Information Systems. The limited information provided by the data makes building boundary and roof structure extractions become essential tasks when analysing the data. This research examines the limitations of different algorithms for extracting building outlines and remodelling roof structures from the LIDAR data solely, and suggests an alternative approach for reconstructing buildings using raw LIDAR data. Most of the current methods use additional data sources (e.g. cadastral data, aerial photos, or satellite images) and pre-defined building models to reconstruct 3D buildings. The extraction method proposed starts by re-sampling the captured data in a lower resolution index layer and the aim is to search for vertical wall segments which separate the high and low areas. The wall segments found are connected and modified to form closed building outlines and corners. The roof remodelling system suggested starts by creating a triangulation using the extracted data points which are inside the building boundaries. Three clustering methods are used to separate the triangles into groups which share the same properties (e.g. orientation and geographical location). Each group of triangles represents a plane on the roof. Plane to plane relationships are found, and the building corners and roof ridges are calculated by using the three planes intersection. Finally the building is reconstructed from the terrain model using a set of well-developed toolkits to extend the TIN model with preserved topological connectivity. Real LIDAR data are used to evaluate the capability and the validity of the developed algorithms. The data were captured in Bournemouth by the Ordnance Survey UK. In conclusion, several suggestions are made to improve the algorithms for future development.

The generalization process works on independent image-objects formed by a closed-boundary and a corresponding enclosed-region on the classified image. Initial image-objects are obtained by integrating the classified image with a geographically corresponding satellite-derived edge-segmented image. The generalization process is organised in two main levels of abstraction. Firstly Geometric generalization, responsible for the spatial and thematic simplification of the classified image, elaborating the initial image-objects in to higher-level polygons (the spatial basis of the final product). Secondly Semantic generalization, responsible for the thematic conversion of the simplified product, associating each higher-level polygon to the most appropriate land use class. The CORINE land cover classification scheme was taken as the target product during this thesis. The classification scheme is however overly detailed for direct comparison with satellite-derived products. To overcome this an intermediate classification was defined in this thesis: Pseudo CORINE (Pcor), which is a 1-level scheme containing: bottom-level CORINE classes which are automatically recognisable by image processing techniques, and 2nd-level CORINE classes as substitutes for those CORINE classes not automatically recognisable. The definition of the Pcor scheme allowed an automatic nomenclature conversion, organised in two steps: 1)re-labelling, based on syntax matching, of low-level classes presenting a one-to-one relationship with a single Pcor class. 2)contextual reasoning, based on mutually exclusive hierarchical rules, for the conversion of low-level classes which present a one-to-many relationship with Pcor classes. A fully automatic generalization process has been developed and verified during this work. The automatic generalization process has produced generalized products which are in excellent agreement with the target CORINE map. The simplification of geometry and content of the input information based on image-statistics and contextual rules is fully automatic, unsupervised, consistent, objective, repeatable and generally applicable.

In the United Kingdom (UK) uncontrolled fires in upland moorlands have a negative effect on biodiversity, soil stability and nutrient dynamics. The control of these fires may be problematic because of the inaccessibility of the terrain. This research aims to investigate whether vegetation Fuel Moisture Content (FMC), a key variable influencing fire ignition probability and rate of fire spread, varies temporally and between species types in the UK uplands and whether FMC can be estimated using optical remote sensing. Ground-based measurements of vegetation variables, including FMC and spectral reflectance, were collected on a monthly basis from March 2008 to March 2009 for six study plots at Burbage Moor in the Peak District, United Kingdom. The FMC for the study plots was calculated and compared to the ground-based spectra directly, and correlated with first derivative and narrow-band vegetation indices. FMC was found to vary temporally and with vegetation type. Reflectance variability with FMC was strongest in the near infrared and shortwave infrared regions. The correlation between reflectance and FMC was higher when the first derivative and narrow-band vegetation indices and in particular Moisture Stress Index (MSI) were used. To extrapolate the results to a landscape scale, two hyperspectral images, for May 6 th and July 1 st 2008, were obtained by the Natural Environment Research Council Airborne Research and Survey Facility (NERC ARSF). Concurrently with the flights, in-situ field measurements were made. With the airborne data, the strength of the relationships between FMC and the spectral data sets were also explored using linear regression. Results from the airborne data confirm the results of ground-based measurements in terms of reflectance variability with FMC and in terms of the strength of the spectral correlation with FMC, FMC correlation with the first derivative and FMC correlation with narrow-band vegetation indices. Within the airborne data, the broad band MSI, which was calculated based on the spectral wavebands of Landsat ETM, was also found to have a significant correlation with FMC. This relationship, which was unknown before the current study was performed, offers the potential for operational application of remotely sensed data for FMC estimation at landscape scales. The implication of this is that remote sensing could have a role in timely mapping of fire risk for large areas of moorland.

A global positioning system (GPS) is an innovative type of technology which can be used to increase efficiency and productivity within the surveying discipline and to produce more accurate results. GPS technology is becoming a very popular and effective tool for surveying purposes worldwide. In developing countries like Libya, this technology has not been adequately implemented. This research is aimed at developing a framework in order to improve the use of GPS surveying technology by the Libyan public surveying sector (LPSS). A critical review of the literature formed an initial conceptual framework. Furthermore, a set of factors were identified and presented in the conceptual framework; these factors were human, organizational and technical factors. The research is qualitative in nature, employing a case study approach and using semi-structured interviews as the main data collection tool within the Libyan public surveying sector. Several tools such as documentation and observations were used in order to achieve triangulation. This approach allowed revisions to be made to the theoretical framework derived from the literature by the researcher. A series of in-depth interviews were subsequently conducted with the Libyan Survey Department personnel to validate the factors and refine the conceptual framework in the context of the Libyan public surveying sector. The contribution of the research is to develop a framework to help the Libyan public surveying sector to establish a strategic policy to improve the use of GPS surveying technology in the Libyan public surveying sector (LPSS).

This thesis describes the results of three field studies concerned with the utilisation of terrestrial laser scanning in the river environment, over different spatial scales. Existing research and technical literature has also been reviewed relating to scale, form and process in the river environment, conventional measurement techniques and the general utility and testing of terrestrial laser scanning technology. In physical geography and geomorphology, scales of interest in the river environment can range from very small scales such as an individual grain up to large scales that cover entire floodplains or catchments. Improved measurement and spatial representation of the river environment over all these scales will reduce error and improve confidence in research into river form and process. Terrestrial Laser Scanning (TLS) - sometimes referred to as Terrestrial LiDAR (Light Detection and Ranging) - is an exciting and relatively new measurement technique that is based upon the time-of-flight principles of laser pulses from a static origin. The term "scanning" relates to the way that the laser pulses are systematically deployed and received in an automated fashion over a swath by the main measurement unit. These data are acquired from a terrestrial perspective, which gives the technique an advantage over airborne measurement and terrestrial contact measurement methods. This research's aim is to evaluate the performance of TLS as a tool for measuring and representing the river environment, whilst focusing on three distinct scales of river features - the reach scale, the floodplain/braid plain scale and the grain scale. Overall, TLS has proved itself to be an extremely useful tool for measuring and representing (spatially and temporally) the river environment, whilst focusing on various scales and features. This is especially the case when investigating rivers at the reach and plain scales. If used correctly, it can undoubtedly provide scientists and engineers with the data that they need to increase their knowledge of river environment form and process. The findings of this thesis have many broader implications relating to how TLS should be used and how it fits into the suite of measurement tools that we have at our disposal.

A stable slow setting cationic emulsion has been developed, suitable to coat dense graded mixtures high in fine aggregate content, in particular gap graded rolled asphalt type and dense graded macadam mixtures. The slow setting emulsion, NH-10, is the outcome of an investigation into five different formulations using two surfactants, two adhesive agents and a water shading compound. The rheological studies of the NH-10 emulsion have shown that it possesses a thixotropic behaviour. The thixotropic behaviour has been justified by the "complex flow" coefficient, a technique proposed by Traxler for bitumens. The viscosity of the emulsion is greatly influenced by the amount of binder and level of temperature. The hardness of binder does not change appreciably the viscosity value of the emulsion. The highly stable mildly cationic emulsion has been used to prepare two types of dense bituminous mixtures containing limestone aggregate, river sand and limestone filler, blended in appropriate proportions. The study presents information regarding the properties of two dense graded bituminous mixtures i. e. a gap graded "Cold Rolled Asphalt" (C. R. A. ) and a continuously graded "Dense Emulsion Macadam" (D. E. Mc). A design procedure based on a modified Marshall method and the evaluation of permeability and creep stiffness is proposed as a laboratory method for the design of the bituminous mixtures developed. The evaluation of permeability and creep stiffness is carried out with equipment designed and developed specially for this investigation.

GPS is the most widely used satellite navigation system. By design, there is no provision for real time integrity information within the Standard Positioning Service (SPS). However, in safety critical sectors like aviation, stringent integrity performance requirements must be met. This can be achieved using special augmentation systems or at the user sensor level through Receiver Autonomous Integrity Monitoring (RAIM) or both. RAIM, which is considered as the most cost effective method relies on data consistency, and therefore requires redundant measurements for its operation. An external aid to provide this redundancy can be in the form of an Inertial Navigation system (INS). This should enable continued performance even during RAIM holes (when no redundant satellite measurements are available). However, the integrated system faces the risk of failures generated at different levels of the system, in the operational environment and at the user sensor (receiver) level. This thesis addresses integrated GPSIINS architectures, the corresponding failure modes and the sensor level integrity algorithms used to protect users from such failure modes. An exhaustive literature review is conducted to identify the various failure modes. These are then grouped into classes based on their characteristics and a mathematical (failure) model is specified for each class. For the analysis of failures, a simulation of a typical aircraft trajectory is developed, including the capability to generate raw measurements from GPS and the INS. The simulated GPS and INS measurements for the aircraft are used to evaluate the performance of the current integrity algorithms. Their performances are assessed for the most difficult case of failures; slowly growing errors (SGE), and shown to be inadequate (i.e. a considerable period of time is required for detection). This is addressed by developing a new algorithm based on the detection ofthe growth rate ofa typical test statistic (assuming a single failure at a time). Results show that the new algorithm detects slowly growing ramp-type errors faster than the current methods, with a forty percent improvement in the time it takes to detect the worst case SGE. The algorithm is then extended to include detection of multiple SGEs for which a new tightly coupled method referred to as the 'piggyback architecture' is proposed. This method provides the novel capability of detecting all failures including those affecting the INS. The proposed algorithms are validated with real GPS and INS data. In this way, the integrity performance of the integrated system is enhanced against the worst case failures with a detection time that is beneficial for the achievement of stringent time-to-alert requirements. A practical implementation would then comprise of the use of the rate detector algorithm alongside the current methods.

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