Landmarks play an important role in spatial cognition and navigation. Humans have long used landmarks for determining and describing positions and routes. The principle of determining position by means of spatial relationships to unique or prominent objects in physical space is used in most means of radio-navigation even today, though the objects may be unique or prominent only to the radio-navigation system. Even with the recent explosive growth in satellite navigation systems for both personal use and in various means of transportation, landmarks are still important wherever a human is the primary actor in navigation or route planning, description, or monitoring. (How long and to what extent this will continue to be so, given location-aware systems, location-based information, driverless cars, and other autonomous transport, is a fascinating and complex subject deserving a much longer discussion than space allows, and will not be addressed here.)
Postulating a human role, advanced artificial aids will still need to address the human use of landmarks. In the urban environment, people generally are primary actors in route planning, description, and monitoring (mass transit excluded, though one still needs to get to and from train stations, and so on). This monograph is aimed at filling the gap between human spatial cognition and reasoning about landmarks and the way information systems model landmarks, reason with and about them, and use them in interactions with human users. It is a timely, well-researched, and well-written review of perceptual, cognitive, and computational modeling perspectives on the question of landmarks in the urban environment.
Chapter 1 is an introductory chapter that sets up the fundamental conceptual framework for the rest of the book, defining the ontological basis for landmarks from different philosophical approaches and discussing the differences between models of landmarks in human cognition and artificial intelligent systems. Chapter 2 includes examples of their effects and uses for structuring mental representations of space. In chapter 3, the authors address the human cognitive aspects, such as orientation, wayfinding, and mental models. Chapters 4 and 5 deal with how databases and computational systems can identify, describe, store, and analyze landmarks, and use them in spatial reasoning and descriptions of spatial constructs such as routes. Algorithms in pseudocode for certain processing tasks are included. The use of landmarks to clarify and enhance the user experience in end-user interfaces is covered in chapter 6. Chapter 7 contains a very brief summary of the material presented in the previous chapters, and outlines what an intelligent geospatial system should aim for, obstacles to accomplishment, and a research agenda for dealing with some of the problems.
The context of this monograph is limited to urban settings, and while the fundamental concepts and many human cognitive aspects carry over to nonurban terrestrial contexts, and aeronautical and marine navigation, there is little discussion of issues outside the urban domain.
Researchers and graduate students in the computer and geographical sciences will find this an interesting and informative review of research and concepts in its scope. Unusually for a book of this type, the intended audience includes the “interested public,” in which the authors include technologists working on web map systems, people using navigation services, and members of the general public who are interested in why certain things are difficult for computers. The content is presented in a lucid and coherent fashion, contains some (but not too much) pseudocode and programming notation, and should be accessible to all members of its intended audience. It still contains much that is substantial enough for the more academic parts of its audience, with depth and detail in the content and several references to the research literature. This book is a very readable and instructive resource for those interested in geospatial representation and reasoning and related subjects, especially in urban settings.