Indoor Spatial Information

Geographic Information Science focuses traditionally on spatial information of geographic scale and associates this per default with outdoor environments. Systems, databases and models are designed for this primary purpose. In this paper, the author discusses the geographic information requirements in indoor environments and, in particular, their differences to ‘outdoor’ geographic information. The main difference, as argued, is that the third dimension is an essential factor for indoor spatial information, while this is not necessarily so for outdoor information. As a consequence, information technology designed for outdoors is not necessarily fit to model, analyze or communicate about indoor space. DOI: 10.4018/ij3dim.2012010102 26 International Journal of 3-D Information Modeling, 1(1), 25-42, January-March 2012 Copyright © 2012, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. making process. Such considerations can even help quantifying the demand in terms of the value of indoor spatial information (Frank, 2000; Krek, 2002). Human indoor activities are numerous and belong for example to everyday tasks like orienting or wayfinding in buildings, to specialists’ tasks like facility management or management of the flow of traffic or goods in a building, or to exceptional tasks like evacuating a building in an emergency scenario. These activities create a significant demand on indoor spatial information. Actually, figures are reported that the average North American now spends approximately 90% of their time indoors, with activities like working, living, shopping and entertaining (American Physical Society, 2008, p. 52). We may safely assume that similar figures apply to other societies as well. It is also safe to assume that people spending this time indoors are not always in environments well-known to them, and that indoor environments have a certain rate of change (in emergency situations this rate can even be quite rapid). The latter raises the stakes for dynamic and (near-)real-time indoor information. Another challenge lies in the fact that people are not only staying indoors, but are moving between indoors and outdoors for many of these listed activities. Their decision making processes are not confined to indoor environments. Satisfying this demand requires significantly different knowledge than the provision of outdoor spatial information. There are several reasons, and some evidence, to assume that the main reason is indoor space being an enclosed space, in contrast to outdoor space. In outdoor environments most activities are limited to a common surface. In indoor environments the third dimension appears in the form of discrete levels, i.e., multiple surfaces. People have more difficulties with wayfinding decisions that involve multiple levels (Hölscher, Meilinger, Vrachliotis, Brösamle, & Knauff, 2006). In addition, indoor space is also private space. This means that access is restricted and regulated. Thus, knowledge about the provision of spatial information that was created for outdoor space must be scrutinized, extended or revised when it comes to indoor space. This paper investigates the characterizing properties of indoor spatial information. It will outline the emergence of indoor spatial information on the research agenda of the discipline and clarify some terminology issues in the next section. Then the notion of ‘indoor’ will be investigated by complementary linguistic approaches, by etymology, by contrasting with outdoor space, and by image schemata. These perspectives help then to identify a list of special characteristics of indoor spatial information. While the paper focuses on this ontological and conceptual level, it ends highlighting how recent research relates to the identified characteristics of indoor spatial information. It also advocates that integration between indoor and outdoor spatial information is required to provide seamless spatial information in support of a fundamental human activity—navigation.