Since ancient times it has been clear to mankind that in order to create topographic maps of the area, it is easier to make observations from above and draw the data obtained. This way, it’s possible to get information on a much larger scale and more informative than from the ground.
Aerial photography is a type of work, which is used to obtain plans of the area with high accuracy and with reference to any network of coordinates. The main tool used for this is an unmanned aerial vehicle. It transmits all necessary data to special devices on the ground. The result of such work is a digital map of the area in detail.
The data obtained during aerial photography is particularly applicable in cartography for determining the boundaries of territories, land management, species survey, archaeology, environmental studies, production of movies and commercials, etc. However, there is also an alternative — observation from space. Current and historical satellite images offer many benefits that aerial photography cannot provide and vice versa.
How Does It Work
Depending on the object and purpose of research, the aerial observation can be conducted in three main ways:
- Aerial photography used to obtain color or monochrome images of various buildings, plots of land and other objects. This can be topographic or planned aerial photography.
- Aerial panorama to get panoramic pictures from a bird’s-eye view. These photos can be used to create advertisements and presentations.
- Aerial video. A variety of aerial photography that involves the use of a video camera to obtain video material for promotional video clips, films, and video tours.
Modern aircraft are affordable, easy to operate, and the photo and video equipment installed on unmanned aerial vehicles allow for getting an image or video with high resolution and excellent detail. In addition, aerial photography of an area may be the only way to view an object when other methods cannot be used. In many cases, this may be the best solution.
How It Started
The history of aerial photography goes back a couple of centuries. With the development of photographic technology, it became clear that aerial photography had great potential. It appeared in the 1950s, when the first hot-air balloons came out. Gaspard Tournachon was the first to take photos of the French capital from a height of several hundred meters in 1858. And with the appearance of dirigibles, airplanes, and other flying machines, this type of photography only kept gaining popularity, resulting in first historical aerial photos, long time before historical satellite imagery joined the game.
But flights on airships and balloons at that time were too expensive, so it was not profitable to use them. A simpler and more accessible way was needed. Then in the early 20th century, Julius Neubronner, a pharmacist from Germany, proposed his method. He adapted a small camera on a pigeon, which gave the method its name — pigeon photography, which was used even during the First World War. Actually, war gave a big boost to aerial photography development. It was widely used to obtain information about the forces of the enemy. Widespread use of aerial photography for geodesy and cartography also began during the First World War. Australian pilots took to the air specifically to photograph the terrain, and new maps were made from these images.
For a good half of the 19th century, the idea of unmanned aerial survey planes was shelved, despite the very successful use of heavy drones for aerial surveys in Vietnam. A new breakthrough in the development of aerial photography began in the 21st century with the rapid evolution and popularization of quadcopters.
In contrast to aerial vehicles, satellites can cover vast areas without complicated logistics or scheduling of flights. More so, they are easily accessible online. Users can type “historical satellite images of my house” in a search engine and get multiple results on providers that offer both up-to-date and archive satellite imagery and its analytics for a variety of purposes.
Aircraft face major constraints: the need for permits, planning of takeoff and landing points, and compliance with the restrictions on the area to be surveyed. Aerial surveying also depends on weather conditions. Satellites simply don’t face such issues (except the cloudiness factor). They can easily collect data from isolated, conflicting, or transboundary locations, which is critical for large-scale mapping projects.
As with aerial photos, satellite imagery can also be integrated into programs using artificial intelligence to pull out the necessary data automatically, optimizing workflows. One of satellite imagery providers is EOSDA LandViewer, offering pictures of different resolutions, taken at different times, and ready to be analyzed right on the platform. The users can just select their area of interest and desired date when the image was taken to get the list of available images meeting the request. The criteria can be the image type, cloudiness, selected area coverage, and more to narrow down the query and view only fitting satellite images.
The amount of satellite imagery gathered over time compared to that of aerial photography offers unmatched possibilities for ML programs. In addition, users can take advantage of historical satellite images and their analysis for modeling and forecasting, which is critical for trend analysis, mass-scale anomaly detection, and profitability estimation.