Geospatial Web Service Chaining

In the context of Geographic Information System’s evolution from monolithic systems to personal desktop GIS and then to collections of remote Internet services, we discuss the combination or chaining of distributed geospatial web services. The adoption of web services technology provides remote access to a diverse and wide array of geospatial datasets and allows developers to create web applications (web browser-based or GIS client-based), hiding the underlying server functionalities from their public interfaces. A major challenge in working with these remote services, as opposed to a single desktop application, is to properly integrate ad hoc services to build a coherent service chain; this is especially tricky in real-time scenarios where web applications need to be built on-the-fly. This chapter discusses strategies for geospatial web service chaining and poses some challenging issues, many related to semantics, to be resolved for geospatial web service chaining to become a commonplace activity.

Design and Implementation Approaches for Location-Based, Tourism-Related Services

The globally observed recession of mobile services market has pushed mobile network operators into looking for opportunities to provide value added services on top of their high cost infrastructures. Recent advances in mobile positioning technologies enable services that make use of the mobile user location information, offering intuitive, attractive applications to the potential customer. Mobile tourism services are among the primary options to be considered by service providers for this new market. This chapter presents the key concepts, capabilities, and considerations of infrastructures and applications targeted to the mobile tourist, covering data and content delivery, positioning, systems’ interactions, platforms, protocols, security, and privacy as well as business modelling aspects.

Geographic Visual Query Languages and Ambiguities Treatment

The main issues of spatial databases and Geographic Information System (GIS), concern the representation, the management and the manipulation of a large and complex number of spatial objects and spatial relationships. In these systems many concepts are spatial and, therefore they are intrinsically related with a visual representation, which makes also easier to formulate queries by non-expert users. The main problems in visual query languages for spatial databases concern imprecision, spatial integrity and ambiguities in query formulation. Our concern in this chapter is with the ambiguity of visual geographical queries. In particular, a review of existing visual query languages for spatial databases and their classification on the grounds of the methodology adopted to resolve the ambiguity problem are provided.

GeoCache

GML is a promising model for integrating geodata within data warehouses. The resulting databases are generally large and require spatial operators to be handled. Depending on the size of the target geographical data and the number and complexity of operators in a query, the processing time may quickly become prohibitive. To optimize spatial queries over GML encoded data, this chapter introduces a novel cache-based architecture. A new cache replacement policy is then proposed. It takes into account the containment properties of geographical data and predicates, and allows evicting the most irrelevant values from the cache. Experiences with the GeoCache prototype show the effectiveness of the proposed architecture with the associated replacement policy, compared to existing works.

Managing Uncertainty in Geospatial Predictive Models

Geospatial predictive models often require mapping of predefined concepts or categories with various conditioning factors in a given space. This chapter discusses various aspects of uncertainty in predictive modeling by characterizing different typologies of classification uncertainty. It argues that understanding uncertainty semantics is a perquisite for efficient handling and management of predictive models.

A Package-Based Architecture for Customized GIS

In this chapter we present a package-based component architecture for the specific deployment and maintenance of public sector applications, specifically corporate Geographical Information Systems (GIS). The three-tier architecture defines a group of server-side packages, a kernel and external packages, that are dynamically requested and assembled at execution time according to the needs of individual users to produce on demand customized GIS applications. An intermediate middleware layer handles user authentication and version control. In order to demonstrate the proposed architecture, a practical prototype has been implemented using Java WebStart. This prototype demonstrates the creation of several GIS client applications, with increasing levels of functionality, and based on free software packages.

Virtual Environments for Geospatial Applications

This article explores the application of virtual environments to 3D geospatial visualization and exploration. VR worlds provide powerful functionalities for model generation and animation and are indeed a valuable tool for geospatial visualization. Subsequently, related issues such as the constraints in progressive terrain rendering, geographic data modeling, photo-realism in virtual worlds, and the system performance with relatively larger files are discussed. Nevertheless, to accomplish the desired results and to attain a higher level of functionality, a good level of experience in VR programming and the jurisprudence to choose the appropriate tool are necessary. Although a standalone VR application is not capable of a higher level of interaction, using the SCRIPT nodes and the External Authoring Interface additional functionalities can be integrated. Intended for use over the internet with a VR browser, such virtual environments serve not only as a visualization tool, but also a powerful medium for geospatial data exploration.

Location Privacy in Automotive Telematics

Over the past few decades, the technologies of mobile communication, positioning, and computing have gradually converged. The automobile has been a natural platform for this convergence where satellitebased positioning, wireless communication and on-board computing work in tandem offering various services to motorists. While there are many opportunities with these novel services, significant risks to the location privacy of motorists also exist as a result of the fast-paced technological evolution. These risks must be confronted if trust and confidence are to prevail between motorists and service providers. This chapter provides an overview of the current situation of location privacy in automotive telematics by exploring possible abuses and existing approaches to curb these abuses followed by a discussion of possible privacy-strengthening measures.

Location-Based Performance Tuning in Mobile Sensor Networks

The author of this chapter considers the location-based approach for performance tuning that significantly facilitates the challenge of utilizing Mobile Sensor Networks. The authors introduce mobile nodes that can be deployed in conjunction with stationary sensor nodes to perform mission critical surveillance and monitoring tasks. It details the past advances in this field and discusses other approaches to this challenge.

Coupling GPS and GIS

Since the 1990s, the integration of GPS and GIS has become more and more popular and an industry standard in the GIS community worldwide. The increasing availability and affordability of mobile GIS and GPS, along with greater data accuracy and interoperability, will only ensure steady growth of this practice in the future. This chapter provides a brief background of GPS technology and its use in GIS, and then elaborates on the integration techniques of both technologies within their limitations. It also highlights data processing, transfer, and maintenance issues and future trends of this integration.