Preserving Local History in Three Dimensions Jerrad Lancaster (bio) introduction With the rise in functionality and cost efficiency of unmanned aerial vehicles (UAVs) over the last decade, aerial photography has become increasingly available to a wider audience of professionals (for example, archaeologists, historians, artists) and hobbyists. Three-dimensional (3-D) technologies have accordingly grown in capability and affordability, their use most notably incorporating applications within cultural heritage and historical preservation.1 Such applications come at an opportune time as important cultural heritage [End Page 64] objects are increasingly under threat due to climatic disasters, funding decreases, and war.2 The latter has garnered attention in the destruction of ancient historical monuments in the Middle East.3 The history of our community gradually fades with each passing day, and photogrammetry provides technological means to digitally preserve historical structures. Discussed here are the applications of photogrammetry and 3-D technologies, and their uses on structures of cultural heritage importance in northeast Ohio. uavs and photogrammetry In recent years, 3-D technologies have been employed in archaeology and architectural history to reconstruct objects digitally and disseminate the models to a broader audience via the internet.4 Not only can an object be preserved at a single moment in time, but that object can be seen by historical enthusiasts [End Page 65] on the other side of the world. It brings new life and new interest to pieces of local history that may otherwise succumb to the effects of time and humans. Photogrammetry creates 3-D models through algorithmic computations to align various aspects of digital photographs; in following this methodology, an object needs to be photographed from every possible angle. Low-altitude aerial photography (LAAP) makes this possible. For over 150 years, unmanned applications of aerial photography have attached still, and later video, cameras to various apparatus, including balloons, kites, blimps, poles, and even pigeons.5 This can be useful for any purpose, from geography, archaeology, or civil mapping, to reconnaissance in times of war. Through LAAP, areas previously difficult or impossible to photograph become accessible with relative ease. However, there are various hindrances surrounding the precision of these methods. Height, focus, and accuracy of the intended target cannot be guaranteed and environmental conditions—wind, shade, direct sunlight, rain, etc.—can also be problematic. The only solution would come in repeating the process until the desired photographs are attained, which is a time-consuming endeavor. These issues can be overcome through ground-based, manned photography—such as scaffolding, cranes, turrets, or ladders, allowing for more regularity and quality in results. Unfortunately, reaching the necessary height can be difficult or unattainable, coupled with the additional challenges of safely securing and constructing the required equipment. Advancements in UAVs (also colloquially known as drones) make their use the most effective tool for aerial photography. Unmanned aerial vehicles originally arose for militaristic purposes in the mid-twentieth century, but by the end of the century were adapted for LAAP uses.6 Initially these UAVs resembled airplanes and helicopters and included very little more than what was needed to get the vehicle aloft and take pictures. While the helicopters incorporated vertical takeoff and landing capability, the fixed-wing airplanes necessitated large, open areas. Easily the largest deterrent to using these early models was the cost and potential loss in the event of a crash. Because of this, any project would conceivably require not only a substantial budget but an experienced pilot. [End Page 66] Recently, technological advances have allowed for more powerful computers at smaller sizes and reduced cost. At the beginning of the twenty-first century, UAVs began to be produced for recreational use, and Dà-Jiāng Innovations (DJI), the world's largest manufacturer of commercial drones,7 began selling its first model in 2006. Traditionally built with four propellers, these quadcopters provide better stability and maneuverability than a single-blade unmanned helicopter. Most importantly, as these recreational drones were mass produced for commercial sale, the cost associated with UAV-based photography dramatically decreased. Concurrently, the technological capabilities of these drones have increased to include autonomous flight and obstacle avoidance, making aerial photography safer for any inexperienced pilot. The environmental factors mentioned above can still cause...
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Aug 30, 2024
Shouyu Cheng + 4
Open Access