Pix4D’s Sonja Betschart on mapping Christ and girl power

Last week we wrote about Pix4D’s successful attempt at creating the first high resolution, 3D model of the Christ the Redeemer statue in Rio de Janerio, said to be Brazil’s most important monument.

It’s a seemingly impossible project, but they did it. This week, we caught up with one of the project teammates, Sonja Betschart who also happens to be Pix4D’s Chief Marketing Officer.

Sonja on a Drone Adventures mission

Drone Girl: How did you get involved in the Rio project?
Sonja Betschart: I got contacted in early 2014 by a professor, Celso Santos, of the 3D lab of PUC University in Rio through DroneAdventures. The lab had been looking into how to get an accurate 3D model of the statue for over 15 years, including using laser scanners to do so. The project was just never feasible when it came to getting both results for the whole statue and affordable technology. When the professor saw one of our projects (mapping the Matterhorn in Switzerland with drones and Pix4D software), he hoped that this new technology would allow him to finally transform his dream into reality.

DG: What was the most challenging part in planning the project?
SB: The huge amount of data acquisition, which needed to be done in a very specific way with special hardware. Although DroneAdventures would have loved to do the project, they lacked the hardware and believed that Pix4D might be a better fit because of its specialization in this kind of data acquisition. We knew that we were in for an “all-around challenge” when it took us over 9 months just to get the approval to fly a drone on the heritage site, which belongs to the Archdiocese of Rio de Janeiro.

Photo: Pix4D and Aeryon Labs

DG: Why did it take 9 months to get approval?

SB: Flying drones is always tied with local legislation. To fly a drone in Brazil, one needs approval from the local government. The local government would only give us the necessary permission to fly our drone if the Archdiocese of Rio de Janeiro, to whom the site of the Christ the Redeemer statue belongs, also gave us permission from their side.

DG: What was it like once you were actually on site?

SB: Amazing and very emotional! When you plan such a unique project for over 9 months and are in contact with the local partners without knowing them in person, it was a very emotional day when we finally met in person and came all together at the base of the Christ statue, to do our “onsite reconnaissance” on the first day. We were all overly excited, but also felt that this was only the beginning of our adventure. We had planned out the whole mission in detail over the previous months and being on site confirmed once more that you can plan all you want, in the end, plans will change and possibly many things will not go according to plan.

DG: And how was the wind up there?

SB: We planned for October as this is historically the best month when it comes to weather. Well, this was certainly not the case in October 2014 as we were surprised all week long with storms, rain and heavy gusts of wind. It was impossible to fly at the end of the day, after the visitors left, because too much wind developed by then. This left us with only a few short hours of data acquisition in the morning, before the first visitors arrived on site. This short time slot (from between 7 to 7:30 am, depending on the day, to 8:30 am at the latest) didn’t give us many options: bright light and shadows on the two sunny days, and general light conditions on very foggy and cloudy days.

DG: Apart from your job at Pix4D, you also do work for DroneAdventures. What’s that?

SB: DroneAdventures is a not-for-profit organization with the goal of promoting the civilian use of drones and drone mapping technology: focusing on the domains of conservation, humanitarian, culture and search & rescue. We fly missions all over the world and want to connect people who know drones and drone mapping best with people who need this technology the most. Having had organized and done missions with DroneAdventures in my free time helped a lot with knowing what to plan for on a project such as Mapping the Christ, especially when it comes to logistics.

DG: What plans do you have in the future? More projects like the Christ?

SB: There will be more projects we will do in the future, though they certainly will be very different from making a 3D model of a statue (we have done possibly the most difficult statue in the world already). We do such projects to test out new limits of our still very new and fast-growing technology and we are always looking for new mapping and modeling challenges that have either not been feasible without image processing technology or are a real challenge to our technology. In 2014, for example, we were the first to map the inside and outside of a huge castle in Switzerland – the Chillon Castle – using only consumer grade cameras. Such projects help us move ahead, pushing back boundaries and showing the world all the good things that can be done with drone imagery. In addition, we gain real experiences out in the field, facing challenges that our customers are exposed to on a daily basis.

DG: Anything else you want to add?

SB: Standing at the foot of the impressive Christ the Redeemer statue in Rio, acquiring imagery with a drone, then taking the images home and using them to finally reconstruct the statue in detail on our computers has been an amazing experience. Though what I am possibly even more proud of is the fact that this very challenging technological project has been done with 90% “Girl Power.” Apart from Celso Santos of PUC University in Rio and two of our male R&D colleagues here at Pix4D who helped out with advising on the data acquisition and with the final touch-ups of the reconstruction, all technical parts of this project has been powered by girls: Aeryon’s very talented UAV pilot, April Blaylock; my colleague Lisa Chen here at Pix4D who did the full reconstruction; and me, taking care of all the technical and logistical coordination. We certainly had a good laugh thinking that “Jesus in 3D” is a result of not only technology but also girls.