Discovering Petra: Archaeological Analysis in VR

n field archaeology, analysis of an excavated region is a meticulous process requiring exploration at a variety of levels. While the act of excavation offers the best way for archaeologists to monitor close-range details, they can use empirically based analysis to analyze only the findings to which they themselves have been exposed. With a team of people excavating, synthesizing the wealth of observation from one year to the next is difficult. Archaeologists also use quantitative methods to compare findings throughout the site over time to pinpoint base trends among recorded artifact typologies. 1 Quantitative approaches, unfortunately, are often limited because they lack a spatial component—explicit information about the physical 3D relationships among the excavated objects and the site. In this article, we chronicle a col-laborative effort (from 1997 to the present) with Petra Great Temple archaeologists to augment traditional analysis approaches. We introduce new archaeological analysis tools that combine novel visualization and interaction techniques within a Cave Automatic Virtual Environment (CAVE). 2 These tools I give archaeologists access to formerly inaccessible parts of the archaeological record; I support navigation and interaction with virtual trenches, stratigraphy, artifacts, and architecture; and I preserve and display the spatial relationships present before excavation. Using an iterative approach and working with archaeologists from the Brown University-sponsored excavations at Petra, Jordan, we built four successive prototypes, each of which refined tools from earlier prototypes and added new tools to help users query, navigate, and explore site findings in three dimensions and at different scales. The tools incorporated new visual representations for the many data values associated with each artifact to highlight patterns and anomalies in the record. Evaluation of the fourth and final prototype shows that our system provides an environment and tools that facilitate empirical analysis by familiarizing team members with data from many years. It also lets multiple team members corroborate observations while examining the record together. Finally, it provides a model of the excavation site where quantitative results can be visualized in context with other aspects of the data collected on site. The " Related Work " sidebar discusses other researchers' efforts to develop similar tools. Figure 1 shows Jordan's Petra Great Temple site, which was the underlying focus of our archaeological tool development. Some of the most important research questions archaeologists at Petra ask during excavation and site analysis include these: I What's the chronology of the architectural phases at the Petra …