What is photogrammetry? Find out all the details!

Have you heard of photogrammetry? It is a type of art, science and technology that aims to obtain images to measure and map the world around us.

This technique will use the art of photography to create representations of the position, size and characteristics of certain objects in the space they occupy.

What is photogrammetry?

Photogrammetry is a measurement and mapping technique that uses the art of photography and images to obtain accurate information about physical objects and the environment.

It is a derivation of photography, its name comes from the set of three Greek words: photon (light), graphos (description) and metron (measurement).

This technique is used in areas such as topography, agriculture, archaeology, cartography, geology, engineering and many other disciplines.

Photogrammetry is a valuable tool for creating three-dimensional models, maps and accurate representations of the real world.

The basic principle of this technique is triangulation, which involves capturing two or more images from different points of view, whether of an object or an area.

And based on these captured images it is possible to calculate the three-dimensional points of what is in perspective.

This process requires the use of known reference points, called control points, to ensure the accuracy of measurements.

When talking about photogrammetry, we have three different options that can be used: terrestrial, aerial and underwater.

• Aerial Photogrammetry: used for topographic surveys, area mapping and environmental monitoring. In this modality, images are captured with aircraft or drones;
• Terrestrial photogrammetry: this type of photogrammetry uses images captured by ground stations, where the cameras are located on tripods or vehicles;
• Underwater photogrammetry: used to map the ocean floor.

How does it work?

The first step is to obtain images of the object or area you want to map. These images can be captured from aerial cameras, ground cameras, drones, satellites, or other image sources.

It is also necessary to identify control points to reference the images and provide a coordinate system. The points can be physical or natural features identified throughout the images.

Based on the points and information about the position and orientation of the cameras, the photogrammetry software will perform triangulation calculations to determine the three-dimensional coordinates of the points in space.

And it is based on these coordinates that 3D models of maps or objects can be generated, models that can be used for various purposes, such as topographic mapping, urban planning and others.

The accuracy of this technique will depend on several factors, including the quality of the images, the accuracy of the control points, adequate overlapping of the images, and the skill of the software used.

These are all the processes that photogrammetry goes through in order to achieve the necessary objectives.

Where is photogrammetry used?

Photogrammetry can be used in several areas, as it has a high capacity to map and measure the world accurately using analog or digital photos.

Here are some ways to use the technique:

Topographic mapping

Photogrammetry is often used to create detailed topographic maps of large areas, including natural landscapes and urban environments.

Important source of information for infrastructure planning, natural resource management and geological studies.

Urban Planning and Architecture

Used by architecture professionals, photogrammetry will also be used to create three-dimensional models of cities or buildings.

This resource will be used for large projects and even for monitoring urban growth.

An example of this can be seen in 3D models of architectural projects or in 3D drawings at the architecture school itself.

Environmental Monitoring

Photogrammetry is vital for monitoring environmental changes. For example, it can be used to track deforestation in Amazon, assess the retreat of glaciers at the poles and monitor the growth of urban areas to mitigate environmental impacts.

Archaeology and Conservation

This technique can also be used to document and, especially, preserve archaeological sites and historical monuments.

It allows you to create accurate digital models that are valuable for research and restoration.

Natural Disaster Monitoring

In natural disaster situations, such as earthquakes and floods, photogrammetry is used to assess damage, calculate the extent of affected areas, and assist in response and recovery efforts.

Precision Agriculture

One field that makes extensive use of the photogrammetry method is agriculture, where it can monitor crop development, identify areas with growth problems and calculate indexes.

With this, the farmer can obtain better results and optimize their production processes.

Civil engineering

It is common to use photogrammetry in civil engineering to be able to carry out inspections and assessments of infrastructure such as bridges, dams and others.

It can also be used for planning, calculations and support when starting construction.

Geology

Geologists use photogrammetry to study complex geological formations, identify mineral deposits, and accurately plan mining operations.

Entertainment

With the advancement of technology, there is 3D photogrammetry software that allows the creation of games, films, animations and other visual resources, improving graphics and the experience.

Advantages of photogrammetry

In addition to knowing about the concepts and where the photogrammetry technique is being used, we can also learn about the advantages of this method and its application.

The use of photometry allows images to be captured with precision, obtaining clearer and more concise results, if executed correctly.

Furthermore, it is a method non-intrusive that does not need to come into contact with the object or place being mapped, something very valuable when used for the preservation of cultural heritage.

Modern technology also allows this technique to capture large amounts of data and images, making the entire process more efficient. effective for very large spaces or objects.

Another advantage of photogrammetry is its versatility, as it can be used in a wide range of areas, as we can see in its applications. It is flexible enough to meet a wide variety of needs.