The wide availability and increasing affordability of camera-capable drones, also called UAVs (unmanned aerial vehicles), has been a great boon in recent years to interest in photogrammetry by professional and amateur photographers alike.
And with modern software systems now on the market, it’s easy to take precise measurements and make accurate 3D models from photos take with even the most ordinary camera (drone or no drone.)
Photogrammetry software and tools have numerous worthwhile applications, some of them business oriented but also for personal projects.
An example of UAV photogrammetry might be taking measurements in land surveying, mapping the scene of an accident for a tort case, or measuring the size of a large coal pile in the mining industry. Geological studies, damage inspection to property following a natural disaster, and surveying the slope of agricultural land to predict water drainage, are yet additional usages – and these lists don’t even come close to exhausting the possibilities.
How Does Photogrammetry Work?
To recover the exact position of a surface point, measure the exact distances between points, or build a 3D representation of a scene or object from a photograph can be done with the aid of modern photogrammetry computer software. But how is it done? And what metrics must be known to make these applications possible?
First, to measure the distance between two points in a photo, the scale of the photo and what it contains must be known. And the photographic image plane must be parallel to the plane on which the two points lie.
Second, to create a 3D model from a 2D image, you need multiple 2D photographs taken from different angles. These images are loaded into your computer and your photogrammetry software creates a baseline and traingulates the elevation of the point or points in question. Given sufficient photos from a variety of approaches, and you could create a 3D image (and then model) of an entire object or landscape.
Finally, it is even possible to use photogrammetry in conjunction with high speed photography and remote sensors to analyze motions made by photographed objects. The software compares the images to determined distance and direction of movement – and you can then plug in the time it took to make those motions to figure out speed.
The mathematics involved in these kinds of determinations is extremely complex, but software systems help make it fast and easy.
Why the Marriage of UAVs and Photogrammetry?
Photogrammetry began in the mid-1800’s, long before the existence of UAVs. But when you want to analyze a landscape from an aerial position, drones are the perfect tools to use for the job.
Whether quad- or hexa- copters or fixed-wing UAVs, these mini-aircraft can get into tight spaces, hover over or wheel around a point of interest, keep themselves consistently level to the ground, and can be easily maneuvered and managed from a computer or remote control.
And it’s much more affordable to get high quality and high volume results out of a UAV with a powerful camera attached to it than to try using full-sized aircraft or settling for satellite images. Drones are simply the most convenient, simple to use, and cost-effective way to survey anything from the air that you wish to extract photogrammetry measurements from.
Unconventional Uses of Photogrammetry
Aside from professional uses, UAVs and accompanying photogrammetry software open up a wide range of “fun” or “unconventional” usages as well.
Here are just a few ideas: making an accurate 3D model of your home and lot to display in the living room, planning out a long distance trek or a serious hunting trip, or transferring homemade artwork into 3D digital form for easy online sharing.
Thus, both professional and private use of UAV or even handheld camera based photogrammetry software programs give plenty of room to both your practical side and your creativity.