The presence of human geologists is held by some to be essential to the conduct of field geology on remote planetary surfaces, so a field study was conducted to observe and characterize the nature of that presence. This study was conducted in the Mojave Desert of Southern California at the Amboy lava field, a landscape that is analogous to terrain on Mars. Two experienced planetary geologists were interviewed and observed during the conduct of surface operations. Each subject then wore a head-mounted video camera/display system, which replaced his natural vision with video vision, while attempting to conduct further surface explorations.
In this study, methods of ethnographic observation and analysis have been coupled with object-oriented analysis and design concepts to begin the development of a clear path from observations in the field to the design of virtual presence systems. The existence of redundancies in field geology and presence allowed for the application of methods for understanding complex systems. As a result of this study, some of these redundancies have been characterized. Those described are all classes of continuity relations, including the continuities of continuous existence, context-constituent continuities, and state-process continuities. The discussion of each includes statements of general relationships, logical consequences of these, and hypothetical situations in which the relationships would apply. These are meant to aid in the development of a theory of presence. The discussion also includes design considerations, providing guidance for the design of virtual planetary exploration systems and other virtual presence systems. Converging evidence regarding continuity in presence is found in the nature of psychological dissociation. Specific methodological refinements should enhance ecological validity in subsequent field studies, which are in progress.