EgoViz – a Mobile Based Spatial Interaction System

This paper describes research carried out in the area of mobile spatial interaction and the development of a mobile (i.e. on-device) version of a simulated web-based 2D directional query processor. The TellMe application integrates location (from GPS, GSM, WiFi) and orientation (from digital compass/tilt sensors) sensing technologies into an enhanced spatial query processing module capable of exploiting a mobile device’s position and orientation for querying real-world 3D spatial datasets. This paper outlines the technique used to combine these technologies and the architecture needed to deploy them on a sensor enabled smartphone (i.e. Nokia 6210 Navigator). With all these sensor technologies now available on one device, it is possible to employ a personal query system that can work effectively in any environment using location and orientation as primary parameters for directional queries. In doing so, novel approaches for determining a user’s query space in 3 dimensions based on line-of-sight and 3D visibility (ego-visibility) are also investigated. The result is a mobile application that is location, direction and orientation aware and using these data is able to identify objects (e.g. buildings, points-of-interest, etc.) by pointing at them or when they are in a specified field-of-view

Developing a spatial data infrastructure for Rwanda : case study of land administration sector.

Thesis (M.Env.Dev.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.Governments all over the world are being challenged to develop Spatial Data Infrastructure (SDI), to improve the access and use of spatial data for decision support and sustainable development. Therefore, SDI is part of the basic infrastructure that needs to be efficiently implemented and managed in the interest of any nation. The aim of this study, therefore, is to assess the feasibility of SDI implementation in Rwanda, using the Land administration geospatial data sector as a case study, given time constraints of the research. To achieve this, the concept of SDI is firstly explained in order to provide a common understanding of the concept. The new trends in the new Land Administration System of Rwanda, with emphasis on spatial data management are also presented. This information is generated from various written materials. Field work was also conducted by means of questionnaires, interviews and observation in attempt to assess Land Administration geospatial data, related assets and gaps with reference to SDI framework requirements. A situational analysis is carried out from the field work results. The research sets the scene providing the major findings. The main spatial data providers are public and based on national level. Land use and cadastral related spatial data are the least developed, and Land Administration application data are quiet non-existent. Various users, mainly decision makers, exist but lack effective access to data. A number of challenges, such as a high duplication of data collection and maintenance, lack of appropriate ways of data sharing, a shortage of human resources in Geo-information, absence of policies and regulations, are also found in the Land Administration spatial data sector. Nevertheless, the new Land Administration System orientations and national priorities in terms of information technology, offer a favourable environment for the implementation of SDI. Having considered this, the research proceeds to propose a Land Administration SDI prototype with its main application of Spatial Data discovery Facility, and then highlights its benefits. The research ends with a conclusion and recommendations for future research

Towards a Scalable Dynamic Spatial Database System

With the rise of GPS-enabled smartphones and other similar mobile devices, massive amounts of location data are available. However, no scalable solutions for soft real-time spatial queries on large sets of moving objects have yet emerged. In this paper we explore and measure the limits of actual algorithms and implementations regarding different application scenarios. And finally we propose a novel distributed architecture to solve the scalability issues.Comment: (2012

Using GIS to Optimize the Design and Implementation of the RTK Reference Network in Abu Dhabi

Several challenging applications and construction works demand real-time measurements for positioning at the centimeter-level accuracy. This positioning accuracy can be obtained by using a Global Positioning System (GPS) roving unit and employing a single reference station (base-station) or through utilizing the service of multiple reference stations forming a Real-Time Kinematics (RTK) Reference Network. The limitation of the single reference approach is that measurement errors are distance dependent and good accuracy can be only obtained when distances are less than 10 kms. In addition, this method requires a nearby Geodetic Control Point (GCP). Recently, RTK reference networks are widely established in modern cities all over the world. The popularity of RTK reference networks is due to the benefit of providing real-time accurate and consistent GPS data over a wide geographical area using a single GPS rover without the need to be referred to a nearby GCP. Designing and implementing an RTK reference network is a challenging task. The system performance and cost are highly related to the distance between stations, nature of buildings hosting the reference stations as well as type and methods of communications. Thus, a modern tool such as the Geographic Information Systems (GIS) that can integrate geographic information and several types of heterogeneous data can be used to effectively optimize the design and implementation of the RTK reference network. This research discusses the use of GIS as an advanced tool to study efficient approaches for designing and operating the Global Navigation Satellite System (GNSS) RTK reference network in the Emirate of Abu Dhabi, United Arab Emirates. GIS functionality is mainly used for manipulating, analyzing, evaluating and presenting the results of different design and implementation approaches. The main design aspects that are considered include: reference station locations, their distribution and separating distances, station site selection and the communication methods. Recommendations concerning the selection of the most appropriate options for designing and operating the system are given. As a result of the study, to ensure precision and reliability, it is proven that station distribution and selection can be best based on service demand while maintaining the user buffer of a radius of 35-50 km from the nearest reference station. Finally, some of the applications that can be integrated with the RTK reference network are explored and analyzed. Focus is made on the integration with Machine Control & Automation due to the benefits of providing increased production and efficiency to many phases of the construction projects

Mobile 2D and 3D Spatial Query Techniques for the Geospatial Web

The increasing availability of abundant geographically referenced information in the Geospatial Web provides a variety of opportunities for developing value-added LBS applications. However, large data volumes of the Geospatial Web and small mobile device displays impose a data visualization problem, as the amount of searchable information overwhelms the display when too many query results are returned. Excessive returned results clutter the mobile display, making it harder for users to prioritize information and causes confusion and usability problems. Mobile Spatial Interaction (MSI) research into this “information overload” problem is ongoing where map personalization and other semantic based filtering mechanisms are essential to de-clutter and adapt the exploration of the real-world to the processing/display limitations of mobile devices. In this thesis, we propose that another way to filter this information is to intelligently refine the search space. 3DQ (3-Dimensional Query) is our novel MSI prototype for information discovery on today’s location and orientation-aware smartphones within 3D Geospatial Web environments. Our application incorporates human interactions (interpreted from embedded sensors) in the geospatial query process by determining the shape of their actual visibility space as a query “window” in a spatial database, e.g. Isovist in 2D and Threat Dome in 3D. This effectively applies hidden query removal (HQR) functionality in 360º 3D that takes into account both the horizontal and vertical dimensions when calculating the 3D search space, significantly reducing display clutter and information overload on mobile devices. The effect is a more accurate and expected search result for mobile LBS applications by returning information on only those objects visible within a user’s 3D field-of-view

Mobile 2D and 3D Spatial Query Techniques for the Geospatial Web

The increasing availability of abundant geographically referenced information in the Geospatial Web provides a variety of opportunities for developing value-added LBS applications. However, large data volumes of the Geospatial Web and small mobile device displays impose a data visualization problem, as the amount of searchable information overwhelms the display when too many query results are returned. Excessive returned results clutter the mobile display, making it harder for users to prioritize information and causes confusion and usability problems. Mobile Spatial Interaction (MSI) research into this “information overload” problem is ongoing where map personalization and other semantic based filtering mechanisms are essential to de-clutter and adapt the exploration of the real-world to the processing/display limitations of mobile devices. In this thesis, we propose that another way to filter this information is to intelligently refine the search space. 3DQ (3-Dimensional Query) is our novel MSI prototype for information discovery on today’s location and orientation-aware smartphones within 3D Geospatial Web environments. Our application incorporates human interactions (interpreted from embedded sensors) in the geospatial query process by determining the shape of their actual visibility space as a query “window” in a spatial database, e.g. Isovist in 2D and Threat Dome in 3D. This effectively applies hidden query removal (HQR) functionality in 360º 3D that takes into account both the horizontal and vertical dimensions when calculating the 3D search space, significantly reducing display clutter and information overload on mobile devices. The effect is a more accurate and expected search result for mobile LBS applications by returning information on only those objects visible within a user’s 3D field-of-view. ii

Investigation of data models and related requirements affecting the implementation of a multipurpose cadastre system in Malaysia

One aim of this study was to investigate the state of development of multipurpose cadastre systems (MPCs) internationally, and, based on the findings to design a multipurpose cadastre data model enhancing the current cadastre system in Malaysia. A second aim was to determine the organizational and legal requirements for implementing a multipurpose cadastre system, within the current Malaysian context. As a final aim, the service oriented architecture (SOA) concept was examined to investigate how it might support the storage, maintenance and delivery of the different layers of data found in an MPC. The data model and service oriented architecture were developed using Oracle Spatial technologies and the SQL language. Sample data from the national digital cadastre database, utility data and topographic mapping data from Malaysia were used in the case study. The investigation enabled data from various agencies to be integrated into a single multipurpose cadastre database in the Oracle Spatial database environment, and a case study of an easement as a legal land object was executed. It was discovered that it was beneficial to show the complete legal situation of a parcel compared to the previous system where the user had to manually search for legal documents and deal with the ambiguous locations of legal land objects. The results of the SOA investigation showed that the application of the SOA concept to the construction of an MPC database will require extensive IT investment, especially a high specification server, but it is expected to reduce redundancy in data collection and processing and reduce the costs. The study also showed that existing legislation in the National Land Code 1965 should be amended. The principal conclusion is that an open source system should be adopted before any further investment in IT software and hardware is made. Another conclusion is that a multipurpose cadastre system has to be managed by personnel highly trained in spatial, programming and IT competencies. An open source system combined with the SOA concept seems the best option if a multipurpose cadastre system is to contribute to the sustainable management of land resources within a rapidly developing Malaysia