GIScience Research at the Twenty‐ninth Annual ESRI International User Conference

The nine articles included in this special issue of Transactions in GIS were gathered from a special call for abstracts and will be presented in research sessions scheduled on the second day of the Twenty-ninth Annual ESRI International User Conference. A total of 39 abstracts were submitted and nine were selected by the journal editors for the preparation of full journal articles. Each of the manuscripts has been through the usual journal peer review process and the final versions included in this issue have been revised in light of both the reviewer’s and editor’s suggestions. They cover a wide range of topics and address some of the key concepts and applications of geographic information science from a variety of perspectives. Some address data capture and representation issues, others describe specific software components and tools, and still others discuss collaborative decision-making, geo-design and visualization challenges. The first article by Paul A. Zandbergen presents an evaluation of the accuracy of locations obtained using the Assisted GPS (A-GPS), WiFi and cellular network positioning modes on the 3G iPhone. The strengths and weaknesses of these three positioning technologies are presented in terms of coverage, accuracy and reliability, and the implications of the results for Location Based Services (LBS) that rely on the 3G iPhone and similar mobile devices are discussed. The second article by Kathleen Stewart Hornsby and Naicong Li shows how text documents that contain movement verbs can be analyzed for deriving representations of movement or dynamic paths. The authors show how movement descriptions in text can be mapped to a set of elemental components including source, destination, route, direction, distance, start time, end time and duration which, in turn, capture the spatiotemporal characteristics of the path of a moving object as described using natural language. The third article by Alain Tamayo, Joaquín Huerta, Carlos Granell, Laura Díaz and Ricardo Quirós presents the software engineering development process followed to build the gvSOS client module that allows gvSIG users to interact with Sensor Observation Services (SOS) servers, displaying the information gathered by sensors as a layer composed by features. The authors discuss the main obstacles – the restrictions of the gvSIG architecture, inaccuracies in the OGC specifications, and a set of common problems found in current SOS server implementations available on the Internet – and potential solutions during each step in the development process. Transactions in GIS, 2009, 13(s1): 1–3