ITR: Graphical Navigation of the Earth in Space and Time

University Of Utah, Salt Lake City UT

Investigators

Abstract

Graphical Navigation of the Earth in Space and Time An explosion is occurring in the availability of on-line data relating to archeology and related disciplines such as paleontology, geology, and paleohydrology. Much of this is geometric information, either scanned from the real world or hand-modeled. Our research aims at utilizing a variety of tools from computer graphics to allow access to this data in a natural manner. Our specific interest is in developing novel methods for displaying how cultural artifacts change over time and space. Ultimately, we envision what amounts to a spatial/temporal graphical browser for data related to the Earth. A session with the hypothetical system A user's browser displays the view from the University of Utah over Salt Lake City with the Great Salt Lake visible on the horizon. The images have the pen-and-ink and watercolor style of architectural \presentation graphics" with detail and texture indicated with just a few strokes, and most colors muted to make the lines prominent. This is the same style used in most manuals and textbooks. The user first moves across the rendered city in the air, looking down at the bustling people and traffic. A particular building catches the user's eye. The user clicks the mouse and a web browser brings up information known about the building, such as its being built in 1870. The user adjusts the time indicator back to 1870. Over the course of thirty seconds (based on the user's preference settings and heuristics) the adjacent buildings come and go, and a trolley system appears and disappears in front of the building. The user is now in 1870 and has a much clearer view of the lake to the west. The user moves to the lake, and can see moving water and small amounts of human activity. The user now more aggressively moves backward in time to 9000 B.C. and watches the shores of the lake fluctuate widely as the water rises and falls. Now the user asks the system to "flag" areas where the database has high densities of unsynthesized data. A flag appears to the west of the lake. The user zooms to this and sees two caves. A click on the caves opens a browser window that indicates the caves are the oldest known inhabited sites in Utah, and were used over several thousand years by paleoindians. The user enters Danger Cave, and observes a group of paleoindians preparing food over a fire. The user now turns selects "uncertainty rendering". Here objects in the database that are stored with a high confidence are rendered with clean lines and detailed textures. Objects stored with low confidence are drawn with sketchy lines and no color. For example, the petroglyphs near the mouth of the cave still exist and thus have high confidence. Petroglyphs in the back of the cave, if they existed, have been destroyed by rock fall and erosion. They have been created speculatively by the archeologist based on other sites, and are thus drawn with low confidence. Note that the system merely accesses archaeologic data. More sophisticated archaeologic uses would be done by other programs, just as the current Web is not used for general data manipulation. The user now exits the cave and asks for the nearest significant events in the past and future near the cave. In the future is shown the arrival of agriculture in the area around 200 A.D. In the past is shown the draining of Lake Bonneville around 10,000 B. C. Here the ancestor of the Great Salt Lake, spanning most of the state of Utah and having an average depth of hundreds of feet, lost most of its water volume through a collapsed narrow pass into the Snake River. The user selects the beginning of the past event and can see the shores of the giant lake, and a variety of wildlife including mammoths and giant land sloths. Still in uncertainty mode, there are also a few sketchily drawn humans; it is debated whether paleoindians were present in Utah that early in time. A visual flag indicates an interesting feature to the North. The user can go witness the site of the landslide. By selecting the end of the flood, the user over thirty seconds can watch the inland sea drain, and the shorelines vastly contract. Finally, the user can zoom back to the present day to see the current cultural features and distant lake.