This presentation is part of the 2017 3D Digital Documentation Summit.
Digital Documentation using Aerial Photogrammetry
There will always be a need and place for traditional architectural documentary tools like pens, pencils, paper, and drafting equipment, however despite the time proven success of these tools, they have limitations. Among the difficulties and challenges of traditional documentary methods, especially in today’s architectural world, include such things as scale, the organic, irregular, and free flowing nature of structures, curvature, and abstractness. One of the most challenging aspects of conventional documentary methods tends to be the amount of time it takes to document a structure. Time spent in the field and drawing a site or structure is time consuming. Photography, especially digital photography, and computer programs like Photoshop or AutoCAD, do make the time spent in the field shorter, but there is still a lot of post processing and computer time that needs to be put in. There’s also the fact that some programs have immense learning curves and take either a lot of time to learn or require the user to take classes.
More modern tools, like laser scanners have solved many of the struggles associated with traditional tools. Laser scanners are much better at capturing hard to draw geometry and produce point clouds and three-dimensional models with incredible resolution. However, these too have serious draw backs; the biggest being the price. Also, anyone who has ever used a laser scanner, in particularly a FARO laser scanner, knows that the time it takes in the field to capture the data can be quite lengthy. Furthermore, software is required to register the scans to create the model; unfortunately, some of these too can very complicated and process intensive.
There is another type of technology that can be used for documentation. Even though the technology is relatively young, the idea and concept has been around for well over a century and a half. The concept is photogrammetry. Photogrammetry dates back to shortly after the invention of photography, and aerial photogrammetry dates to shortly after that. The initial drawback to photogrammetry, specifically photogrammetry done with film photography, was that the images needed to be stereoscopic pairs.
Even after the revelations of computers and the ability for these computers to run algorithms, the digital camera technology still had not caught up. Film photographs had to be first scanned and then imported into the software. The bonus of this technique, however, was that the images no longer needed to be stereoscopic, they could be convergent. The algorithm would calculate the camera positions automatically to form the model. Another bonus is the speed in which the photography can be collected.
In today’s world, fortunately, not only have digital cameras more than caught up, computers and photogrammetry software have also become more advanced and powerful. All these technologies are also extremely affordable, as well as extremely portable, now. Three-dimensional models can be developed on our phones. However, there is one technology in particular that has advanced immeasurably and will bring a revolution to photogrammetry: the use of photography equipped drones.
In the last few years, drones have evolved from kid and hobbyist pass time to serious tools with cameras just as, or even more, technologically advanced than handheld cameras, with ranges reaching outward to 8 miles or more, that sync with a dozen or more GPS satellites to keep their position, that are able to achieve speeds and altitudes that exceed most needs. All of this technology makes capturing the digital images exceptionally fast, and accurate. Moreover, along with the advancement of drones has been the improvement of photogrammetry software. These technologies combined result in the ability to have a complete, accurate, to scale three-dimensional model in a matter of hours if not less.
Joshua Jones recently graduated with a MFA in Historic Preservation from Savannah College of Art and Design. His studies there were primary focused on the documentation of historic places, sites, and in particular threatened and endangered structures. Jones feels that he is first and foremost an artist, predominantly a photographer. The most engaging part of photography is the idea that a story can be told or conveying the sense of an adventure or the mood of a scene without saying a single word.