Craig Feuerherdt is currently undertaking a Masters by Research in Applied Science at RMIT University in Australia. Graduating with a degree in Applied Science (Cartography) Craig applied his knowledge to natural resource issues in several government departments. He is currently employed by a small company dedicated to implementing sustainable agricultural landscapes.

William Cartwright is Professor of Cartography and Geographical Visualization in the School of Mathematical and Geospatial Sciences at RMIT University, Australia.  He is a Vice-President of the International Cartographic Association and a National Councillor of the Mapping Sciences Institute, Australia.  He is a member of the International Cartographic Association's Commission on Visualization and Virtual Environments and the Commission on Maps and the Internet.  His major research interest is the application of multimedia to cartography and the exploration of different metaphorical approaches to the depiction of geographical information.  He holds eight university qualifications - in the fields of cartography, engineering, education, media studies, information and communication technology and graphic design.

MOBILE OUTDOOR AUGMENTED REALITY FOR LANDSCAPE SCENARIO VISUALIZATION
C.N. Feuerherdt 1, W. Cartwright 1, M. Black 2
1 Department of Mathematics and Geospatial Science, RMIT University, Melbourne, Australia
2 Spatial Vision, Melbourne, Australia
craigfeuerherdt@gmail.com, w.cartwright@rmit.edu.au, michael.black@spatialvision.com.au
Abstract
Many government departments are undertaking projects looking at the trade-offs between social, economic and environmental factors. These projects are heavily reliant on complex, computer-based models that generate potentially thousands of scenarios which provide land management alternatives to assist land managers determine the most appropriate solution for a given issue or set of issues. These modelling frameworks have become more robust with increased computing power and improved understanding of the natural systems being conceptualised, however scenarios are typically disseminated using static, thematic maps and abstract graphs requiring detailed explanation to fully be understood by their audience. This often results in land managers not fully understanding the long term implications of the land practice change being suggested.
There are a variety of alternate methods for disseminating the complexities of landscape scenarios. Virtual Reality (VR) is a common alternative to traditional static maps allowing users to view scenarios in a wholly virtual world. The implications of scenarios are often difficult to realistically interpret due to a variety of factors including lack of peripheral vision, distance and scale perceptions.
Augmented Reality (AR) provides an alternate method, capable of providing an interactive environment for viewing landuse scenarios while immersed in the physical world. The application of AR to catchment (landscape) management has not been explored.
This paper presents the findings from research evaluating the effectiveness of AR as interface between complex models and the dissemination of those scenarios to land managers.
Introduction
Many government departments are undertaking projects looking at the trade-offs between social, economic and environmental factors, commonly referred to as 'triple-bottom line' accounting. This approach, recognised across Australia as Integrated Catchment Management (ICM) (The State of Victoria, 1999; Murray-Darling Basin Commission, 2004), is essential to the long-term sustainability of a region (Bryan, 2003; The State of Victoria, 2004).
In looking at trade-offs between the various factors, most natural resource projects are now heavily reliant on complex, computer-based models that generate potentially large numbers of scenarios. These scenarios provide land management alternatives to assist land managers  determine the most appropriate solution for a given issue or set of issues. While the integrated modeling frameworks have become more robust with increased computing power and improved understanding of the environmental systems being conceptualised, outputs are generally disseminated using static, thematic maps requiring detailed explanation to be fully understood by stakeholders. This often results in land managers not fully understanding the long term ramifications of their current land management practices nor the benefits of the changes being suggested.
Alternative methods of communicating the complexities of model output are being researched. Virtual Reality (VR) is seen as an alternative to traditional static maps for disseminating the complexity of land-use scenarios to stakeholders. While VR allows users to interact with landscape scenarios in a wholly virtual environment, the true implications of a scenario are difficult to realistically interpret.
Augmented Reality (AR) is capable of providing an interactive environment for viewing land-use scenarios in the physical environment being assessed. The exploration of AR in the context of catchment management is relatively new. The research outlined in this paper relates to the development of appropriate User Interfaces (UI) for interacting with catchment models within a mobile, outdoor Augmented Reality (AR) system. The focus of the research is the development of appropriate user interfaces for an AR system focused on land-use scenario visualization and landscape planning.
Augmented Reality (AR)
Augmented Reality (AR) is a user interface paradigm that supplements (typically) vision with computer generated information, superimposed on the users view (Schmalstieg and Reitmayer, 2007). Augmenting the real world with computer generated graphics provides users with experiences not possible in just the real or virtual worlds (Price and Rogers, 2004). AR resides between wholly Virtual Environments (VE) and reality (Mills and Noyes, 1999; Milgram and Kishino, 1994).
The field of modern AR has existed for well over a decade (Azuma et al, 2001), with origins back to the 1960's when Ivan Sutherland (1968) developed Sketchpad, a man-machine graphical communication system. AR systems are defined by their ability to spatially integrate virtual objects into the physical world in real-time, immersing the user in an information-rich, interactive environment (Azuma, 1997; Feiner et al, 1997; Hollerer et al, 2001; MacIntyre, 2002; Reitmayr and Schmalstieg, 2003b; Romao et al, 2004). Head-Mounted Displays (HMDs) are typically used for visualizing the computer generated images over the real world (Reitmayr, 2004).
While many issues have prevented AR becoming more widely used, the recent availability of higher performance, lower cost hardware and peripherals have made their implementation more practical, however complex technical and scientific problems still exist (Azuma, 1997; Romao et al, 2004). The predominant issue is the registration of the synthetic images with real world features (Azuma, 1997; Gelenbe et al, 2004; Hollerer et al, 2001; Romao et al, 2004). In addition, the ability to interact with AR systems is typically undertaken using unfamiliar input devices. Providing users with the required functionality (land-use scenario design and visualization) within an AR context is the challenge of this research.
Usability engineering design
There are a variety of usability engineering design approaches that are commonly applied to developing information systems and their associated user interfaces. User-Centered Design (UCD) (or Human-Centered Design (HCD)) is an internationally recognised approach focusing on users through the planning, design and development phases (Usability Professionals' Association, 2007). Several authors (including Francis and Williams, 2007 and Norman, 2007) argue that Activity-Centered Design (ACD) is a superior technique to UCD as it analyses and focuses on the task to be accomplished rather than the human requirements resulting in other factors being considered in the design.
Carroll (2000) states that the UCD and ACD methodologies are ineffective at addressing all issues faced during design, offering Scenario-Based Design (SBD) as an alternative. Rather than attempt to control the complexity of the design process by filtering information and deconstructing problems into small tasks, SBD attempts to exploit the complexity of the design process by gaining a deep understanding of the problem from various perspectives (Carroll, 2000). This is achieved through user interaction (problem) scenarios which utilise hypothetical stakeholders to underpin the design process. These problem scenarios are then transformed into activity scenarios, representing the proposed usage scenario.
The SBD methodology has been selected for developing and prototyping the interfaces required in an AR system focused on disseminating land-use scenarios. The research outlined in this paper assumes that AR is an appropriate method of disseminating land-use scenarios.
Six problems scenarios outlining the current practice of developing land-use scenarios have been created. The research has recognised that several problem scenarios are not practical within an AR environment. As a result, five (hypothetical) activity scenarios have been developed, focusing on incremental alteration and dissemination of land-use scenarios by landholders. Five hypothetical stakeholders, based on representative users, act in the activity scenarios. Two represent government employees responsible for implementing the proposed land-use scenario, an additional two represent landowners, each having a different perspective on land ownership. A hypothetical community member with an interest in improving the environment has also been included, acknowledging that better management of the environment is a collaboration between all members of a community (Orland, 1992).
Graphical User Interface (GUI) development
Various AR systems have been assembled over the last decade with a variety of User Interfaces (UI). The limitations of displaying user interfaces within a HMD restrict the amount and quality of information being displayed and the users ability to interact with it. Some systems provide external hardware (such as Personal Digital Assistants (PDAs) or tablet computers) to facilitate user input (Renevier and Nigay, 2001; Geiger et al, 2001) while others allow user(s) to undertake complex tasks within an augmented context using novel interaction devices (such as chording keyboards or haptic gloves) (Piekarski and Thomas, 2003; Reitmayer and Schmalstieg, 2003a; Suomela and Lehikoinen, 2000).
It is proposed that the user interfaces for a land-use scenario AR system be implemented on a PDA, allowing users to interact with a variety of relevant and contextual spatial layers using familiar tools. The HMD would therefore be dedicated to visualization rather than being cluttered with a GUI. The requirements of user interfaces were derived from the activity scenarios.
An AR system focused on landscape scenario visualization needs to provide at least two interfaces. The first, a narrative learning mode will allow users to gain an understanding of complex environmental issues, while the second interface will allow users to interactively explore and propose alternate land-use scenarios at several spatial scales. Each of these theoretical interfaces is explained in more detail below.
Narrative learning
Rather than an explicit interface that requires input from a user, this mode guides the user through a spatial narrative describing a single (or multiple) environmental issue. The narrative is started by a single user (a supervisor) selecting the appropriate option from their PDA which in turn informs the other systems (students).
Each user, wearing an AR system, is guided through the narrative using a 'world-in-miniature' map and navigational arrows displayed in the HMD. Users control the narrative by physically moving to the spatial locations show on the map. The spatially aware narrative starts and stops when the user enters or exits within a proximity of the required location. The augmented graphics displayed in the HMD would be supplemented with audio and additional media including photographs or videos could be displayed, creating a spatially-aware, rich multimedia experience. 
Scenario exploration
This mode of the AR system will allow users to visualize proposed land-use scenarios, input alternate land-use scenarios and analyze the differences between them. Each user has a PDA with a web-based mapping interface, allowing them to control the layers being visualized in the HMD. The environmental (water balance) impacts of the alternate scenarios would determined by a simplified version of the full model used derive the most appropriate land-use scenario.
Manipulation of alternate land-use scenarios will be possible at two spatial scales; landscape and context. The landscape-scale interface will allow users to manipulate major environmental and economic factors (such as water quality, water yield, fibre production etc) using a polar (radar) graph. Adjusting each factor (or axis of the graph) would potentially affect the other factors, reflecting the trade-offs between, for instance, planting large areas to trees for environmental purposes resulting in reduced economic productivity. The resultant scenario could be visualized on the PDA using the mapping interface and through the HMD.
The context-scale interface will provide users with appropriate tools to edit the extent and location of various land-uses at a local scale. The resulting spatial layer representing the ideal or preferred land-use scenario of the user could be visualized through the HMD.
Users will be able to query various aspects of the land-use scenarios using the mapping interface on the PDA and be shown information relating from the catchment model (such as positive or negative water balance). In addition to visualizing a spatial representation of the proposed land-use, various factors could be displayed in a variety of forms such as charts or abstract representations (such as extruded polygons representing the positive or negative impact of a suggested land-use), spatially referenced within the HMD.
Conclusion
While a lot of attention has been focused on integrating the various hardware and software components necessary for mobile, outdoor Augmented Reality (AR) systems, interfaces for interacting with such systems has been explored to a lesser extent. User interfaces are being created for a theoretical mobile AR system targeted at land-use scenario visualization.
The research, briefly outlined in this paper, is attempting to create accessible user interfaces for interacting with complex environmental data sets and models using the Scenario-Based Design (SBD) methodology. The Graphic User Interfaces (GUIs) are being designed for a PDA, providing a recognisable interaction metaphor (touch screen and stylus) while allowing the HMD to be used solely for visualizing outputs. 
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