What is an orthophoto?

An orthophoto corrects the distortions that occur in a normal photograph or satellite image, which can then be used for technical applications such as surveying

What is the difference between a normal photo and an Ortophoto?

Normal aerial photography by helicopter, drone or satellite is subject to distortion due to altitude differences or, in the case of satellite imagery, due to the curvature of the earth. Therefore, normal images cannot be used for accurate tasks such as surveying, as they may have a high degree of inaccuracy. If you want to plan a photovoltaic system on your roof and use satellite imagery for this purpose, there may be some discrepancies. An orthophoto provides a distortion-free and true-to-scale image of a terrain or a building and can be used for surveying or planning.

Applications of orthophotos for commercial purposes

Orthophotos created with drones are used commercially in agriculture, construction, planning, government, and many other fields. Essentially, an orthophoto is used to take aerial photographs to determine land use, plant growth, plan settlements, construction sites, survey, or create city maps. They offer a cost-effective and fast alternative to expensive and time-consuming ground surveys and can be used in areas that are difficult to access, such as mountains or forests.

Orthophotos for private use

Even for private use, drone photography can capture spectacular moments and capture beautiful moments in nature. Thus, in the private sector, orthophotos can be created to get a new view of your house or property. So your property and house can be captured on a very high resolution image with the finest details with the view from above.

Drones and climate change

Orthophotos can also be of great importance in science, as they can help us understand and demonstrate various climate change processes. For example, a glacier can be continuously monitored with orthophotos and melting can be detected and measured. They can also be used to monitor glacial lakes, reservoirs, etc. Or it can be used as a meter to measure sea level rise. Thermographic images can be used to record ground or water temperature and serve as a comparison for future years. Since this is a new technology, we need to use it creatively and discover new applications to protect our planet. Orthophotos taken by drones can be of great importance here, as they can be taken in a cost-effective and environmentally friendly manner.

Drone-captured orthophotos can also quickly reveal meaningful details after natural disasters such as landslides, forest fires or floods. This enables more efficient planning of measures. Especially after mudslides, a 3D photogrammetric model can be used to determine relatively precisely the volume that needs to be removed. As a preventive measure, a specific area at risk can be mapped in advance so that a before-and-after comparison can be made in the event of a mudslide. In this way, very accurate predictions can be made about the volume of the landslide.

So how are orthophotos created?

When creating orthophotos, it is important that the camera is plumb down. It is important to use a drone with a high quality camera to be able to create sharp images during the flight. The drone photos will have the coordinates noted on them that the software will need for post-processing. When planning the flight, care is taken to ensure that the images taken overlap to a certain extent, so that afterwards a high-quality orthophoto of the area can be created in special software for photogrammetry. A major advantage is that drones fly at low altitudes compared to airplanes, helicopters or satellites and can therefore collect very accurate data. These very high resolution orthophotos make the smallest detail visible and can be used for very accurate land surveying.

Which drone should you use for an orthophoto?

To successfully take orthophotos with a drone, you need a good camera and a gimbal that allows the camera to shoot plumb down and hold it in flight without being affected by the tilt of the drone. To get sharp images while flying, you need a professional drone with a high-quality camera to keep the exposure time as short as possible, otherwise you will get blurry or out-of-focus images. Unlike normal photo shoots, which are usually not taken while the drone is moving, hundreds of photos are taken when creating maps. To manage this in a timely manner, photos are taken while the drone is in flight. The higher the resolution of the camera, the more accurate the orthophotos will end up being.

What are the advantages of drone orthophotos compared to satellite imagery?

  • Orthophotos can be created at any time, so they are always up to date.

  • Very high resolution, so that the smallest details are visible.

  • No distortion due to the curvature of the earth, which allows accurate area measurement. E.g. for the planning of photovoltaic plants.

  • Orthophotos with drones are relatively inexpensive and timely to produce.

  • They are available in data formats for integration into GIS application programs.

  • Drones with thermal imaging cameras can be used to create detailed thermal orthophotos of large photovoltaic systems or hall roofs for inspection.

What are the disadvantages of taking orthophotos with a drone?

There are already hundreds of satellites in orbit around the Earth that are used to photograph very large areas, countries or the entire world. With a drone, this would be virtually impossible because a drone has a limited flight time and the drone pilot must be in the vicinity of the drone. Modern drones, however, can map areas as small as several hundred hectares in a short time.

How much does an orthophoto with a drone cost?

The cost is comparatively low, because the flight of a drone is very cheap and also sustainable compared to helicopters or airplanes. We calculate the price according to the size of the area and the location. So, 1 hectare In the mountains costs a little more than 1 hectare of green space in the plains. Traveling to the site also accounts for part of the cost, so large areas will be cheaper per hectare than smaller areas. Contact us and we will give you a no obligation quote for your project.

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Aerial view vs. orthophoto

At first glance, an orthophoto looks like a normal aerial image taken by a drone or helicopter from high altitude, similar to a satellite image. However, an orthophoto image file can contain several hundred MB of data and have a tremendous resolution of the area. In addition, orthophotos are distortion-free and can be used for technical applications in GIS software. The precision and accuracy is thus equivalent to the quality of maps and is suitable for measuring real distances. Due to the enormous pixel accuracy, it is possible to zoom into the image and see even the smallest details in high resolution. Large areas can thus be stored in a single high-resolution image file and processed for further applications. A normal photo taken with a drone, even with a 48MP camera from high altitude, offers very low pixel accuracy, making such an image worthless for technical applications.

Plant health monitoring

Agriculture can also benefit greatly from orthophotos. Drones equipped with multispectral cameras can capture images in special light bands that can provide information about the health of crops. Orthophotos of farmland can also be created with these images, allowing targeted action to be taken if there are anomalies in a particular location. For example, water shortages, pest infestations, fungal infestations or fertilizer deficiencies can be detected at a very early stage before large-scale failures occur. This is an advantage for farmers to ensure a more successful harvest season.

Count tree stand or plant stand in the field

It is even possible to make inventories based on orthophotos. In forestry, for example, an orthophoto can be used to count the number of trees. In agriculture, a field can be flown over to count the number of plants, to see if there are more failures on a certain section, and then to take precise action or make preparations for the coming seasons in certain places. With special software for photogrammetry or orthophoto applications, automatic counting of plants is possible, and the data is clearly displayed on the map.

Our conclusion on orthophotos created with drones

Orthophotos created with drones are already used in many different areas and will become even more important in the future to make our future more efficient. Be it for the protection of our nature, for more efficient management of agricultural land or for inspections on construction sites or photovoltaic installations. Since we are dealing with a new technology, our creativity is needed to make sense of it and add value to our daily lives. If you are interested in a research project or have a proposal for the efficient use of drones, contact us, we are happy to work in the field of research with drones to explore possible new, undiscovered paths with drones.

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