The 3D re-creation and mapping of our world is an ambitious pursuit with the potential for endless possibilities.
Photogrammetry, one of the main methods for creating one-to-one 3D representations of buildings, machine parts, and entire landscapes, is widely used in engineering.
As our technologies become more advanced, so does our ability to make incredible 3D models. Let's take a look at some impressive uses for photogrammetry.
What is photogrammetry?
Photogrammetry is a technological science that creates accurate 3D scans of physical objects using 3D rangefinders and precisely taken photographs. Its humble beginnings go as far back as the middle of the 19th century, to around the same time photography was invented — the French surveyor Dominique F. Arago proposed making topographic maps using photographs in about 1840.
Today, photomapping technologies such as unmanned aerial vehicles (UAVs) and accurate electromagnetic radiant imagery equipment have allowed photogrammetry to move forward in leaps and bounds.
As technology advanced, the field of photogrammetry has become ever more impressive. Here are 11 examples to show you what it can do today.
1. The rebuilding of Notre Dam
You very likely know that part of the Notre Dame cathedral, including the main spire, burned down in April of 2019. You might have also read that it will be rebuilt with the help of millions of mapping datasets collected on the cathedral, including game assets from Assassin's Creed: Unity.
A company called Art Graphique & Patrimoine (AGP) used photogrammetry to take scans of Notre Dame over the course of several years before the fire. They were also tasked with scanning the iconic cathedral after the disaster to help assess the damage.
As AGP said in a press release, shortly after the fire, "the AGP team, in collaboration with FARO, conducted an emergency operation to save Notre-Dame." They produced precise 3D surveys of the building, "in order to establish a diagnosis of the damages."
2. Automotive testing
Photogrammetry is used by the biggest automakers for testing of automotive components. It is often used in the assessment of components used to make up the car body, known as the body-in-white stage of car manufacture.
The nature of photogrammetry allows car manufacturers to assess the body components in a fraction of the time they would otherwise take to do so. The images can then be used in computer-modeled test simulations in order to iron out any problems, before sending the physical model out to a track.
3. Space exploration and engineering
There's a funny story about photogrammetry related to the Apollo 17 Moon landing. During the mission, astronaut Gene Cernan accidentally caught the hammer he had stowed in his calf pocket under the right rear fender of the Lunar Roving Vehicle, and tore off the rearward extension.
Support personnel in Houston helped design a replacement for the fender using tape, a lunar landing site map, which had been made by applying photogrammetry techniques to satellite images, and some spare clamps — the painstakingly crafted map definitely served a purpose, but not the one it was originally intended for.
Today, NASA uses photogrammetry to carry out 4D photogrammetric analyses, single image quantitative analysis, and other techniques to analyze equipment in order to keep satellites working and astronauts safe on the launch pad.
4. The future of mapping
Most of us already have access to a photomap of almost the entire Earth with Google Maps. As photogrammetry mapping technologies improve and are combined with other mapping technologies, Google Maps and similar maps will become more lifelike and will give more accurate representations of the real world.
As Tech Crunch reported last year, for example, a new patent filing by the U.S. Army shows that they are developing a photogrammetric method that uses UAV mapping to make accurate 3D maps from ordinary aerial footage in just minutes.
5. Rebuilding the wreck of the Titanic in 3D
Did you know that the wreckage of the Titanic might be nothing but a rust stain on the ocean floor by 2030? Current estimates say the rapid rate of decay caused by ocean microbes means that the famous cruise wreckage is well on its way to being reclaimed by nature.
Atlantic Productions announced the following in a press statement about their team's scans of the Titanic:
"Using the submersible camera systems, the team performed dedicated photogrammetry passes on the wreck, allowing highly accurate and photoreal 3D models of RMS Titanic to be produced. These assets will help assess the wreck’s current condition and project it’s future, as well as making it possible to visualize the wreck using augmented reality (AR) and virtual reality (VR) technology."
6. Wind energy
Detractors of wind energy often cite the high maintenance and operation costs of wind turbines. Photogrammetry can actually help to ease these burdens and allow for more widespread usage of this clean energy technology.
The gravitational loads and pressures of aerodynamic forces on the blades of wind turbines are very important in determining the efficiency and robustness of the system. With time, blades can be cracked and face other forms of deterioration. Photogrammetry not only helps wind farm owners to detect and analyze the condition of their wind turbines, but it also helps in the development of new models that are more resistant to wear and tear.
7. The study of historic architecture
3D modeling and photogrammetric mapping also have a lot of applications for the classroom. One example is that it can be used to allow students and professors a more detailed and immersive means of studying the history of local architecture.
A study titled, '3D Modeling in the Urban Classroom: Using Photogrammetry for the Study of Historic Architecture in Coral Gables, Florida', is a perfect example of the way photogrammetry techniques can be used for the study of architecture.
The study, published in The Journal of Interactive Technology and Pedagogy, details how a 3D modeling class was taught as a module for a course on Spanish art taught at the University of Miami. The course addressed the impact of Spanish architectural styles on the artistic production of Spain’s colonial possessions.
For delicate archaeological discoveries, such as the 11,500-year-old remains of the Luzia Woman, it's practically impossible to allow the entire relevant scientific community to study it in person.
Photogrammetric techniques allow for the creation of a lifelike digital representation which can be studied from almost anywhere. These techniques even allow the object to be visualized in virtual reality.
9. Subsea exploration
As already explained in the Titanic section, above, photogrammetry is very effective for mapping undersea terrains.
The use of submersibles makes it possible to study and map ancient heritage sites, which are often delicate, without disturbing them and causing further deterioration. Underwater photogrammetry, which is rapidly evolving, might in the future be used to monitor environmental changes and map the deepest oceans.
The many risks involved in mining are well known to both investors and employees. Geospatial data, which can be rapidly collected with photogrammetry techniques, can be used to plan ahead and mitigate some of these risks.
Photogrammetry can be used to develop digital models that show elevation, terrain, and surface in a way that is highly competitive when compared with LiDAR laser technologies which are also used on these types of sites.
11. Civil engineering and architecture
Seeing as photogrammetry can be used for space engineering and the monitoring of satellites, and also on Earth-bound structures such as wind farms, it's obvious that the technique has extensive use in civil engineering.
A study titled, 'Application of a Photogrammetric System for Monitoring Civil Engineering Structures' details how old methods are gradually being replaced by photogrammetry, which allows for more rapid implementation and more accurate readings. Photogrammetry techniques can also be used in cities to monitor huge amounts of data including the structural stability of large buildings and structures.
It seems that photogrammetry is one of many technologies, including drones, virtual reality headsets, and 5G, that is set to shape a future in which we'll be increasingly connected to the digital world.