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Juan Ortiz: «The team of restorers who worked on the reconstruction of Notre-Dame took our experience into account in the development of their work»

Juan Ortiz is a researcher and lecturer in the Agroforestry Engineering department at Campus Terra
Juan Ortiz is a researcher and lecturer in the Agroforestry Engineering department at Campus Terra
Juan Ortiz, researcher and lecturer in the field of Agroforestry Engineering at Campus Terra, reflects in this interview on the possibilities offered by current photogrammetry in the three-dimensional recording of heritage assets

If one thing has been proven in recent decades, it is that technology is one of the greatest allies of scientific research. Improved process accuracy and efficiency, increased global connectivity, and the democratization of tools that were once only accessible to a few are just a small sample of what technology can contribute to our society.

Technology has thus marked a turning point in many fields of research, revolutionizing useful techniques such as photogrammetry: a procedure that uses photography to accurately define the shape, dimensions, and position in space of an object, with applications ranging from the creation of topographic maps to the recording of monuments and archaeological sites.

To immerse ourselves in this exciting universe, today we turn to one of the most established voices in this field: Juan Ortiz Sanz, researcher and lecturer in the Department of Agroforestry Engineering at Campus Terra and member of the CIGEO research group.

-Much of your research focuses on low-cost photogrammetry. What led you to choose this technology, and what have been its main applications?

-There were several reasons why I chose this technology. The first is personal, as I have always been very fond of photography. When I discovered its use as a technical tool for measuring XYZ coordinates in 3D of visible points, which is what photogrammetry achieves, I became even more interested.

The second reason was to see how easy it was to start working with it, thanks to some free, very intuitive and simple computer tools that began to appear a few decades ago.

The third reason was the advent of digital cameras, a real revolution in this field. And the last reason was the incorporation of cameras into mobile phones.

All this meant that photogrammetry evolved as we had predicted and proved to be a winning bet, as we clearly saw some major advantages of this technique over others.

Today, photogrammetry has become much cheaper and simpler, so it has become extremely widespread, both in its most popular use, with free mobile phone applications that anyone can use, and in its most sophisticated use.

With regard to the most popular applications, our group was an international pioneer in online teaching of photogrammetry to high school students with the D3MOBILE championship.

As for the more sophisticated applications, the two most important areas I have worked on are their application to the 3D recording of heritage assets, mainly architectural and archaeological, and the measurement of deformations in characterization tests of various types of construction materials, such as earth or wood, both in the laboratory and in situ.

-You have worked both in heritage documentation and in the characterization of structural wood. What challenges and opportunities do each of these fields present from a photogrammetric point of view?

-In the field of heritage, I believe that some of the challenges today are the development of more documentation tools that facilitate the integration of different technologies, such as drones, LiDAR (Light Detection and Ranging) or artificial intelligence, particularly in the case of submerged heritage and the structural behavior of monumental buildings.

As for wood and other structural materials, I would highlight the robotic optimization of drone routes in photogrammetric flights for recording movements and deformations in the monitoring and load testing of structures or the detection of the axis and sections of structural elements, which improves their use as a tool for validating calculation methods, always with the challenge of achieving a greater number of measurements at a lower cost and with greater precision and accuracy.

-A highlight of your professional career is the photogrammetric documentation of the roofs over the Pórtico da Gloria in Santiago Cathedral. What did you learn from that project, and what impact did it have on your scientific career?

-It is undoubtedly one of the projects I remember most fondly. It was a milestone in our work, with a very complex challenge at a time when the technologies we used were much less developed than they are now. There is an important emotional component due to the significance of working there.

As an anecdote, I would say that we set up a small office at the top of the bell tower itself, on the roof that tourists visit today, with two computers and some tables, where we also kept poles, ropes, cameras...

It was a huge challenge, and we learned a lot, especially about the practical aspects of documentation, which we never lose sight of, as we always think about how what we do can be applied by professionals in the engineering, architecture, and archaeology sectors.

It was a major boost to my professional career, as it was part of one of the first doctoral theses I supervised, one of the first high-impact articles I published and, over time, large teams of internationally renowned restorers, such as those who worked on the recent reconstruction of Notre-Dame in Paris, took our experience into account in the development of their work.

Juan Ortiz participated in the photogrammetric documentation of the roofs over the Pórtico da Gloria Glory at Santiago de Compostela Cathedral
Juan Ortiz participated in the photogrammetric documentation of the roofs over the Pórtico da Gloria Glory at Santiago de Compostela Cathedral

-You have also led projects such as D3MOBILE, which aims to bring photogrammetry to non-university students. Why do you think it is important to disseminate this technology among young people?

-As there have always been free photogrammetric applications, since cameras were incorporated into all mobile phones and with the development of the internet, I saw the potential of photogrammetry for implementing an e-learning project.

We started with a national project, but the following year, we saw that it was possible to go international, so we launched ourselves into the ten editions that were ultimately produced.

I think it's very important to spread the technique among students of this age, because it's a very easy-to-understand and intuitive tool that is now used in practically all professional fields.

If they learn it at this age, whatever they study or whatever they work in later, they will already know about its existence and potential.

They will even be able to delve deeper into it and use it to represent any real object in 3D, improve their presentations, take precise and accurate measurements in 3D with their phone camera or any other camera, etc.

-In your work, you often use accessible technologies such as user cameras and free software. Do you think that the democratization of technology is transforming the way research is conducted and taught?
 

-Of course, as has always been the case: forty years ago, very few people had Super 8 film or video cameras, but today we all have them and we all know how to use them. Back then, the way of teaching and researching was completely different from today.

However, on the other hand, I think it is very important to know that, even though the way we teach or research evolves, we must not lose sight of the fundamentals of what is being taught or researched, because technology only provides and improves tools that allow us to generate more knowledge through research. What is important is the knowledge generated and its transmission to students, rather than learning how to use the tool itself, although this is also important, of course.

-You belong to the CIGEO research group. What lines of research are you currently developing, and how do they fit into the strategic objectives of Campus Terra?

-The lines of research currently being developed by the group are classified into four blocks: Coastal and Water Engineering; Transport Infrastructure; Geomatics and Civil Construction.

All of them contribute to a greater or lesser extent to the strategic research objectives of Campus Terra, as we have had people doing industrial doctorates, Ramón y Cajal grants, forming part of multidisciplinary teams with other faculties and universities, internationalization, etc.

In this regard, it is worth noting that the CIGEO group is actively involved in the strategic objective of consolidating the Institute for Research in Global Health and Sustainable Development (iTERRA) at the University of Santiago de Compostela (USC), mainly in the thematic area of digital technologies and artificial intelligence.

-You have been teaching for more than 25 years. How has your teaching style and relationship with students evolved over the years?

-Teaching has evolved a lot, especially in the sense that it used to be complex and expensive to obtain and provide information to students. In contrast, today, the excess of information can even be a problem.

Otherwise, new technologies allow for more agile continuous assessment, for example, but the essence of what is taught, the most important thing, has not changed much. As for how I interact with my students, I think the most significant change stems from the widespread use of the internet and the possibilities offered by a communication channel that did not exist when I started teaching.

-Finally, looking to the future, what scientific and teaching challenges are you particularly excited about at this stage of your career?

-The challenges remain the same as they have always been. I am passionate about obtaining high-precision, accurate XYZ coordinates of real points using this technique, employing free or low-cost equipment that previously required enormous investments in equipment and could involve risk for the people responsible for obtaining them. That has not changed much.

In the field of teaching, there haven't been many changes either. I have the same enthusiasm as always for helping to train engineers who will continue to contribute to making society better through their work, and engineering doctors who will continue to generate knowledge.

I am also fortunate to be part of the teaching teams for humanities and social science degrees, which is also a source of pride for me, because, in a way, teaching future professionals who specialize in cultural services, without training in geomatics, means putting into practice much of the knowledge generated by research in low-cost photogrammetry.

The contents of this page were updated on 08.28.2025.