GIGAPAN VERSUS DRONE TOOLS: A CASE STUDY OF ROCK SLOPE STABILITY ISSUES AT NATURAL BRIDGE, ROCKBRIDGE COUNTY VA, USA

In recent years, there have been several competing imaging technologies that have greatly expanded the palette of tools available to geoscientists to visually explore terrains. Each technique has its pros and cons, many of which are only realized after extensive field and lab testing. In this research we compare and contrast two of such methods, specifically the GigaPan and UAVs (drones), using the Natural Bridge Arch. We hope that results of our study will help community college students make informed choices regarding which imaging tool to use for their unique educational setting and geologic environments.

Natural Bridge in, Rockbridge County, VA is part of a larger, ongoing investigation of rock stability – a research project being conducted by Radford University with funding from VDOT. This is an important site because of a rock fall in 1997 that resulted in a fatality. Forensic investigations determined that remediation was necessary to maintain structural integrity and public safety. Engineering techniques including rock-bolting, rock-scaling and concrete containment structures were used all of which need to be monitored for natural weathering and deterioration. However, due to accessibility issues, remote-imaging methods had to be employed.

Our comparison parameters include the cost of the software and hardware, accessibility for the average student, ease of use, physical danger and liability, reliability, image resolution and quality, efficiency of acquiring and operating the hardware, processing and sharing imagery, logistics, and suitability for imaging different geological terrains.

As the result of these comparisons, we have determined that the GigaPan is the better option for students due to its overall ease of use for settings similar to the Natural Bridge. Ideally however, if resources allow, both techniques ought to be utilized for their individual strengths.