Photography
How Photogrammetry Has Revolutionized Mapping
Published
2 years agoon
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Marks StrandA map can be defined as a visual representation of space and the relationship between the objects in that space. The difference between an image and a map is that the latter gives specific information about distances, elevations, coordinates, and so on.
Mapping is therefore the process that results in a visual representation of an area, complete with accurate positioning information.
Over the years, various methods have been used to obtain maps. Most of these methods had limitations. For example, they took a long time and were tedious.
But the introduction of photogrammetry, coupled with aerial photography, has transformed the mapping process. It’s now faster and more efficient, as I’ll discuss in this article.
What Is Photogrammetry?
Photogrammetry is the collation of multiple two-dimensional images of the same object to create a three-dimensional representation of that object. The images are “stitched together” using special software.
Photogrammetry is a basic method of coming up with 3D scans. It borrows from the stereoscopic vision of the human eye. We are able to see the world in 3D because our brains combine the images from both eyes, enabling depth perception.
Photogrammetry Mapping
Photogrammetry mapping uses the photogrammetry technique to come up with maps.
An aerial photogrammetry camera is used to capture images of the area being mapped. Multiple images of the area are captured from multiple angles.
On its own, each image is just a normal photograph, mostly useless as a map.
But when the images are stitched together, they turn into a map. The result can be used to tell the distance between two points. It can also be used to tell the actual position of a point – through a coordinate system.
Advantages of Mapping Using Aerial Photogrammetry
The most obvious advantage is speed. With aerial photogrammetry, you can map large areas in a fraction of the time you would take with alternative methods. For relatively small tracts of land, for example in construction or urban development projects, a drone would be sufficient.
If you are mapping an area that spans a continent, you could use an airplane to do it in just days.
And with such time savings come significant cost savings. The less time you use on a project, the less you have to pay for workers and equipment. When projects that might have taken weeks take only a few days, mapping projects become much more feasible.
Photogrammetry mapping is made possible by a number of technologies, including:
- Advanced aerial photogrammetry cameras.
- Modern photogrammetry software.
- Unmanned aerial vehicles.
Photogrammetry in Mapping Has Been Enabled by the Modern UAV Camera
In photogrammetry, the better the quality of individual photos, the better the quality of the end product – in this case the map.
Without a high-quality camera, the results of this type of mapping would be unreliable and unsuitable for most use cases.
Thankfully, UAV camera and payload technology has advanced to the level where it’s possible to take photos of up to 100 MP from a drone. With a lower budget, you can take 50 MP shots.
Combined with the ability of drones to fly lower than manned aircraft, this high-quality results in excellent maps.
Mapping Wouldn’t Be Possible Without Modern Photogrammetry Software
For photogrammetry-powered mapping to work, hundreds or thousands of photos have to be taken over the course of an aircraft’s flight.
These photos have to be taken at the most optimal angles and intervals to ensure the best end product.
And once they’re taken, they have to be stitched together appropriately.
All this is enabled by advanced software, often with elements of artificial intelligence.
Even the flight planning part before flying the drone is controlled using software. The flight plan helps cover the required areas adequately.
Advanced Drone Technology Has Enabled Better Mapping
Modern drones can fly faster and longer. This makes them suitable for small and medium scale mapping use cases.
They are also capable of carrying heavier payloads. Heavier payloads translate to more advanced sensors. This means that drones are capable of carrying higher resolution RGB cameras. Moreover, they can carry other types of sensors such as thermal cameras, making it possible to enhance data collection.
Remote control has also made it possible to use drones to access areas that humans would find it extremely difficult to access.
Modern drones also have advanced features like automatic collision-avoidance systems which make them easier to maneuver, especially in high-risk areas.
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