What is drone photogrammetry and how is it done?

Drone photogrammetry has evolved the way maps and geographic plans are produced by reducing the need for field staff, increasing productivity by reducing the demand on time, and saving money in the process.

What is photogrammetry and what is it for?

Before beginning to explain the use of drones in photogrammetry, it is important to know in detail what photogrammetry is and what it is for in general.

Photogrammetry is a technique used to obtain precise measurements and three-dimensional models of terrain by analyzing aerial or ground photographs. These photographs are taken with airplanes or drones, from different points and angles to obtain different perspectives. Once taken, they are processed and compared to determine the distances between different points on the ground to obtain precise measurements and 3D models.

This technique is widely used in multiple sectors such as topography, archaeology, civil engineering, cartography, agriculture and even for industries such as video games or cinema.

What is drone photogrammetry?

As we have explained in the previous point, drone photogrammetry consists of taking multiple aerial photographs of an object or terrain, and using them to create high-resolution digitized 2D or 3D models from which the necessary measurements can be derived. This can be done with specialized mapping software that looks for similarities in the images and uses them to combine your photos in a way that provides an accurate representation of the space.

To ensure accuracy in drone photogrammetry, it is necessary to take pictures from multiple angles, as a single aerial photograph cannot be used as a photogrammetric map, as issues such as perspective and distortion have not been resolved.

Depending on the scale of the project, creating a photogrammetric model may require a couple of hundred thousand individual images. That's why drones are often the cheapest way to take all the aerial photography you need to create these types of measurements.

Drone photogrammetry applications

The use of photogrammetric maps has allowed the creation of many products from aerial photography. These products include:

• DEM/DTM/DSM technologies (for surface and object modeling).
• Orthophotography (aerial images with geospatial correction).
• 3D models of buildings and objects.
• Contour maps.
• Obtaining planimetric characteristics (roadsides, hills, objects, urbanized areas, among others).
  Images of 3D objects are successfully used to implement projects. Savings are also achieved as a result of better measurement efficiency and reduced costs compared to aircraft.

Thanks to these advantages, the main applications of photogrammetric mapping are the following:

• Management and planning in the forestry field.
• Create flood models.
• Creation of pollution models.
• Topographic survey and cartography.
• Urban design.
• Transportation planning.
• Oil and gas exploration.
• Quarries and mining (calculation of parameters and exploration).
• Archeology.
• Civil Works
• Architecture and Urban Planning
• heritage
• Design of cellular networks.
• LiDAR mapping