Rob Harrap

Evaluating roadside rockmasses for rockfall hazards using LiDAR data: optimizing data collection and processing protocols

Highways and railroads situated within rugged terrain are often subjected to the hazard of rockfalls. The task of assessing roadside rockmasses for potential hazards typically involves an on-site visual investigation of the rockmass by an engineer or geologist. At that time, numerous parameters associated with discontinuity orientations and spacing, block size (volume) and shape distributions, slope geometry, and ditch profile are either measured or estimated. Measurements are typically tallied according to a formal hazard rating system, and a hazard level is determined for the site. This methodology often involves direct exposure of the evaluating engineer to the hazard and can also create a potentially non-unique record of the assessed slope based on the skill, knowledge and background of the evaluating engineer. Light Detection and Ranging (LiDAR)–based technologies have the capability to produce spatially accurate, high-resolution digital models of physical objects, known as point clouds. Mobile terrestrial LiDAR equipment can collect, at traffic speed, roadside data along highways and rail lines, scanning continual distances of hundreds of kilometres per day. Through the use of mobile terrestrial LiDAR, in conjunction with airborne and static systems for problem areas, rockfall hazard analysis workflows can be modified and optimized to produce minimally biased, repeatable results. Traditional rockfall hazard analysis inputs include two distinct, but related sets of variables related to geological or geometric control. Geologically controlled inputs to hazard rating systems include kinematic stability (joint identification/orientation) and rock block shape and size distributions. Geometrically controlled inputs include outcrop shape and size, road, ditch and outcrop profile, road curvature and vehicle line of sight. Inputs from both categories can be extracted or calculated from LiDAR data, although there are some limitations and special sampling and processing considerations related to structural character of the rockmass, as detailed in this paper.

The Application of LiDAR to Assessment of Rooftop Solar Photovoltaic Deployment Potential in a Municipal District Unit

A methodology is provided for the application of Light Detection and Ranging (LiDAR) to automated solar photovoltaic (PV) deployment analysis on the regional scale. Challenges in urban information extraction and management for solar PV deployment assessment are determined and quantitative solutions are offered. This paper provides the following contributions: (i) a methodology that is consistent with recommendations from existing literature advocating the integration of cross-disciplinary competences in remote sensing (RS), GIS, computer vision and urban environmental studies; (ii) a robust methodology that can work with low-resolution, incomprehensive data and reconstruct vegetation and building separately, but concurrently; (iii) recommendations for future generation of software. A case study is presented as an example of the methodology. Experience from the case study such as the trade-off between time consumption and data quality are discussed to highlight a need for connectivity between demographic information, electrical engineering schemes and GIS and a typical factor of solar useful roofs extracted per method. Finally, conclusions are developed to provide a final methodology to extract the most useful information from the lowest resolution and least comprehensive data to provide solar electric assessments over large areas, which can be adapted anywhere in the world.

The art and science of mapping: computing geological categories from field data

Abstract Like many activities in the geosciences, geological mapping of surface bedrock involves the construction of a model for a geographic region via field-based surveys. Individuals interpret field evidence to constrain possible histories and explanations, and these are regularly under-determined by available theory and data, resulting in multiple valid explanatory models where selection of the optimal model is often described as being an art as well as a science. This study empirically investigates this artistry by evaluating the correlation between data collected in the field and the geological map unit concepts interpreted from these data. Several geologists’ data are selected from a completed field survey, and unsupervised and supervised categorization techniques provided by the self-organizing neural network are used to investigate the correlation between the selected data and interpreted concepts. Reported are results suggesting that the development of geological map unit concepts is influenced by theory, data, individuality and specific situations. Significant challenges in preparing largely qualitative data are also reported, and discussed are some broader implications related to the ability of computational techniques to capture and compute with the experiential knowledge of human agents in field-based situations.

Rock bench: Establishing a common repository and standards for assessing rockmass characteristics using LiDAR and photogrammetry

Remote sensing methods are now used to assess rockmass characteristics along transportation corridors, in mines and tunnels, and in other areas where rock falls can affect humans and infrastructure. A variety of sensor methods, primarily LiDAR and photogrammetry, have seen recent use with widespread success and state of practice acceptance. Various commercial and custom tools exist to process the resulting data to extract geometry, surface and location based statistics, and to perform kinematic stability assessments. Although there is a widespread need to assess how different sensors and processing workflows actually perform, these are often compared anecdotally solely with the field practices they replace and using site and sensor data unavailable to other researchers. Two principles must be established to move across-the-board comparisons of remote rockmass characterization forward: (i) establishment of accessible, documented test sites, and (ii) test databases that are accessible to all. We propose the establishment of several key sites for equipment tests, including already-studied areas in Europe and North America, as well as an open approach to adding sites and related data to the collection. Site descriptions must include detailed local geology, photographs, LiDAR and/or photogrammetry datasets, and access notes. Second, we describe and provide a prototype data repository for storing this information, and in particular for providing open access to benchmark data into the future. This initiative will allow for meaningful comparisons of sensors and algorithms, and specifically will support better methodologies for benchmarking rock mass data in the geosciences. Data and metadata will be hosted at the www.rockbench.org domain.

The Application of Smartphone Technology to Economic and Environmental Analysis of Building Energy Conservation Strategies

This paper investigates the use of smartphone technology as a tool to implement building energy audit programmes to increase energy conservation measure (ECM) uptake and concomitant environmental and economic benefits. The smartphone audit analysed provides an energy audit platform with: (i) quasi-real time analysis, (ii) continuous user engagement, (iii) geospatial customization, (iv) additional ECMs, (v) ECM ranking and user education, and (vi) the ability to constantly evolve. A case study of 157,000 homes in Southeastern Ontario shows that 55 years is needed to complete energy audits for all dwellings in the region following a traditional energy audit model. However, the results of the smartphone-based audit programme accelerates this in both terms of audits completed and cumulative carbon dioxide savings over a sensitivity range of audit effectiveness. It is concluded that an advanced and expanded home energy auditing programme that uses smartphone technology could provide significant economic and environmental benefits.

Design and Implementation of Mobile Educational Games: Networks for Innovation

Research networks foster creativity and break down institutional barriers, but introduce geographic barriers to communication and collaboration. In designing mobile educational games, our distributed team took advantage of diverse talent pools and differing perspectives to drive forward a core vision of our design targets. Our strategies included intense design workshops, use of online meeting rooms, group paper and software prototyping, and dissemination of prototypes to other teams for refinement and repurposing. Our group showed strong activity at the university-centered nodes with periods of highly effective dissemination between these nodes and to outside groups; we used workshop invitations to gather new ideas and perspectives, to refine the core vision, to forge inter-project links, and to stay current on what was happening in other networks. Important aspects of our final deliverables came from looselyassociated network members who engaged via collaborative design exercises in workshops, emphasizing the need to bring the network together and the importance of outside influences as ideas evolve. Our final deliverable, a mobile educational game and a series of parallel technology demonstrations, reflect the mix of influences and the focus on iterated development that our network maintained.

Chapter 19 Exploring conceptual landscapes: The design and implementation of the georgia basin digital library

Abstract The design of Web-based digital libraries for thematic education, concept exploration, and community decision support represents a fundamental challenge in cybercartography. The incorporation of ideas from knowledge representation, education theory and practice, geomatics, cartography, and hypermedia into a consistent and usable suite of tools represents a challenge to both the conceptual architect and the system engineer. The conceptual architecture is hampered by the radically different interface metaphors each of these component approaches embody. The technical architecture is hampered by contrasting and often incompatible system architecture requirements for operation in a Web browser, and by the emphasis on ephemeral trends and approaches in the Web design community. A workable compromise requires balancing the two sets of requirements in a flexible way that honors the audiences core needs. The Georgia Basin Digital Library (GBDL), which supports sustainable development education, community development, and a rich interaction between social and scientific modes of understanding, attempts to accomplish this balance by using interface techniques that directly expose concept semantics and interconcept relationships to users. In GBEx-plorer, the test implementation for GBDL, cartographic and hypermedia tools are driven by a concept-network interface element, although in principle any of the three interface elements can be used for direct engagement. Associated online community support tools provide the ability for users to directly add to the digital library knowledge base at both the information asset and community atlas site-of-interest level. Ongoing research examines two-dimensional versus three-dimensional modes of interaction, supporting technology from artificial intelligence and geomatics, and especially the social impact and role of the digital library.