Digitizing the excavation

The 21st Conference on Cultural Heritage and NEW Technologies (CHNT 21, 2016) took place in Vienna  the first week of November 2016. In that occasion we gave a presentation entitled "Digitizing the excavation. Toward a real-time documentation and analysis of the archaeological record". Today I found the time to publish it in our blog, to share our research regarding this topic and in particular some interesting projects of "archeorobotics" we are working on.

Here below you can see the video of the presentation, done like always with the open source software impress.js and Strut...

... and here is a short description of each slide:

SLIDE 1

The title (strictly related with Digital Archaeology in general)

SLIDE 2

A short presentation of Arc-Team

SLIDE 3

All the work has been done thanks to Free/Libre and Open Source Software. In order to keep going on with our research regarding archaeological methodology we need the source code!

SLIDE 4

The fundamental schema of the archaeological cognitive process elaborated by G. Leonardi in 1982. The schema shows the progressive reduction of the informations regarding human actions before and during the archaeological excavation (Human activities --> Traces on the soil --> Natural and anthropological degradation of the record --> archaeological excavation --> archaeological documentation) until the interpretative knowledge starts recover information during the post-excavation stage (with analitical data interpretation and reconstructive hypothesis)

SLIDE 5

A practical example of the schema from the site of Torre dei Sicconi in Italy (a medieval castle):

1. Human activities (summarized in the building of the castle, the medieval battle and the destruction of the main structure and the controlled explosion during the Great War)

2. Traces on the soil (summarized in the evidences of the battle, of the controlled explosion and of recent agrarian activities, while just negative layers were found regarding the construction of the structure)

3. Natural and anthropological degradation (summarized in the battle, the explosion, the agrarian activities and the normal natural dynamics)

4. Archaeological excavation (the most destructive investigation: in Torre dei Sicconi all the layers concerning the tower and the main central building has been removed by this activity)

5. The importance of archaeological documentation comes from distructive analysis (excavation). Being a long term project, Torre dei Sicconi was documented both with traditional and digital methodology

6. Data analysis. During this stage our knowledge of the site started to grow again. In this case both archaeological and historical techniques have been used

7. Reconstructive hypotheses represent the maximum increase of our (interpretative) knowledge of the site. For Torre dei Sicconi this stage has been achieved just for the central part of the castle (tower and main building)

SLIDE 6

The archaeological excavation is the most critical (destructive) stage of our knowledge regarding a site.

SLIDE 7

Arc-Team's excavation strategies:

1. increasing the amount of information registered decreasing the time-consuming operation of archaeological documentation

2. on-site direct observation for a better interpretation, avoiding at the same time any kind of data selection

3. moving the lab into the field (chemical and physical analyses)

SLIDE 8

A milestone of our research: in 2006 the development of the "Metodo Aramus" gave us a better (more precise and accurate), faster and corect (equalized) 2D digital documentation with FLOSS.

SLIDE 9

Another milestone. Between 2008 and 2009 the migration from pure photogrammetric software to SfM and MVSR methods (through the development of a GUI for +Pierre Moulon's application  Python Photogrammetry Suite) gave us better and faster 3D digital documentation

SLIDE 10

Even today we still use a combination of 2D and 3D techniques to meet different requirements of various archaeological projects

SLIDE 11

2D digital documentation through GIS is fast enough for on site interpretation during emergency excavation

SLIDE 12

A software like +QGIS  allows a direct interpretation on the field without the necessity of long post-rpocessing

SLIDE 13

3D documentation gives better results, but needs longer processing time (even if it does not need long data acquisition on the field, which is always performed)

SLIDE 14

We achieved (a lower quality) 3D data acquisition which has the fundamental characteristic of being real-time, thanks to open hardware (archeorobotics)

SLIDE 15

Our experience in archeorobotics dates back to 2006 with our first prototype of UAV, which could be use professionally just in 2008.

SLIDE 16

Currently or archeorobotics research regards our last prototype of Archeodrone (a UAV specifically designed for aerial archaeology)...

SLIDE 17

... some CNC machines and, above all, the Fa)(a 3D, a 3D open hardware printer which without any kind of modifications was able to satisfy our archaeological needs (like 3D printing casts of unique finds or exctract and print DICOM data form x-ray CT scan)...

SLIDE 18

... and the ArcheoROV, the open hardware Remotely underwater Operated Vehicle which we developed with the +Witlab Fablab 

SLIDE 19

Some pictures of the first test of the ArcheoROV

SLIDE 20

A first step into 3D real-time documentation through SLAM (Simultaneous Localization and Mapping) techniques has been done with the open source ROS (Robot Operating System) and RTAB-Map via Kinect...

SLIDE 21

... and tested for 3D real-time documentation in wooden areas (where SfM and MVSR or laserscab would have been too slow), reaching in almost one hour of work a model (with real dimension) of 75000 points.

SLIDE 22

A benefit of archaeorobotic system like these (which are ROS capable) is the possibility to change the sensor in order to adapt the hardware to different situation, using monocular or stereo cameras (for odometry) as well as LIDAR or SONAR devices.

SLIDE 23

Another benefit is the wide range of possibilities offered by the different open source software (e.g. RTAB-Map, LSD-SLAM, REMODE, Cartographer, ecc...)

SLIDE 24

Currently the precision/accuracy level of a real-time 3D archaeological documentation cannot be compared with the results achieved with post-processing through traditional SfM - MVSR systems, but there are good prospects for improvement.

SLIDE 25

Nowadays, basing on our professional experience, the best use of such devices seems to be during extreme operations, such as high mountain archaeology, glacial archaeology, underwater archaeology or speleoarchaeology

SLIDE 26

Another important step to improve the reaction time of professional archaeology, in order to avoid errors during the critical stage of the excavation, is the possibility to perform some basic archaeometrical analyses (chemical and physical) directly on the field.

SLIDE 27

Considering the composition of any archaeological layer based on two different elements, the skeleton (macroscopic) and the fine earth (microscopic), it is obvious that different analyses can be performed in different work environment.

SLIDE 28

For instance, in the case of the skeleton, a fast petrografic (ontoscopic) analysis can be easily performed directly on the field (defining allogeneic elements), while further (more specific) investigations need an equipped laboratory.

SLIDE 29

Also in the case of fine earth, some raw descriptive analyses can be performed on the field, while laboratory investigation can reach very detailed results (e.g. with the Scanning Electron Microscope).

SLIDE 30

The field analysis of the fine earth is more problematic (compared with the skeleton) the most common test (e.g. the Soil texture by feel) are anametric and subjective

SLIDE 31

For this reason, archaeometric test are the better choice (e.g the sedimentation test)

SLIDE 32

The sedimentation test on the field can be improved with basic physical analysis (e.g. considering the Stoke's Law in order to define sand, silt and clay by the tme they need to sediment)

SLIDE 33

Another implementation on the field for the sedimentation test is the possibility to directly store the data into a PostreSQL/PostGIS database (through some specific fields of the archaeological recording sheet), using the open source application geTTexture.

SLIDE 34

An example of the use of geTTexture

SLIDE 35

Other archaeometric test which are simple to perform directly during the excavation are based on basic chemical analyses, and specifically with the quantification of compounds like phosphates or nitrates.

SLIDE 36

Moreover, with some simple workarounds, it is possible to turn anametric (boolean) analyses of carbonates or organic substances, into metric (quantitative) observations.

SLIDE 37

The Archaeological excavation is a destructive process, subject to fatal (not reversible) errors. Moreover the reduced time and budget in professional and emergency archaeology increase stress conditions during decision making stages.
Real-time 3D mapping can speed up data interpretation, avoiding data selection on the field, while on-site chemical and physical analyses (geoarchaeology and archaeometry) can define a better (data-driven) digging strategy.


I hope this presentation can be useful. Have a nice day!

Gufan, the 2000 year old Brazilian

Background

In 2013 I visited the Paranaense Museum with Dr. Moacir Elias Santos. At that time I was in Curitiba to present the face of an Andean mummy, on the occasion of the II Happy Mommy's Day.

Panel printed with Gufan's facial reconstruction process - Photo: Karen Becker

Dr. Moacir had told me that I would be surprised by the rich collection of the museum. In fact I was surprised, every room I could see pieces and more pieces, which together made up a historical panel, not only of the state of Paraná, but of Brazil and even of other countries.

TV story about the facial reconstruction of Gufan and the use of virtual reality

After dazzling myself with old vestments, pictures, coins and infographics, we arrived at a room where the bones of an abogirinal child of a few hundred years were being presented.

I wasted no time and took a series of photographs of the skull, already with the intention of digitizing it in 3D and later reconstruct it.

As soon as I returned to Mato Grosso, that's exactly what I did. I showed the work to Dr. Moacir and he appreciated it, but he asked me to contact those responsible for the museum so that they would know about the work I was doing, after all, I had not agreed with them to use the pictures.

I called the museum, explained the situation and the clerk transferred me to Dr. Claudia Parellada. Undoing my initial fears, which foresaw a future dominated by coercion, she was interested in the idea of reconstruction and not only allowed me to post the work on my site, but also raised the possibility of building a partnership, since she relied on others skulls, some of them over a thousand years old.

The facial reconstruction project

The story does not stop there. In 2008 I traveled to Curitiba for the first time at the invitation of my friend Alessandro Binhara, to lecture on Blender and computer graphics at the educational institution he was working on. The talk was given and we agreed to one day we would work on a project together.

Steps of facial reconstruction

Nine years passed and the opportunity appeared. I closed an in-house workshop with Mr. Binhara, Beenoculus staff, and my other buddy, the developer Sandro Bihaiko. The plan was to bring together a number of experts and study some applications using virtual and augmented reality.

In the meantime I realized that it was a good opportunity to resume the discussions with the staff of the Paranaense Museum and I went back to talking with Dr. Claudia Parellada and Dr. Renato Carneiro, director of the institution.

I learned then that they had a rich collection of skulls, and among them was Gufan, a 2000-year-old proto-Jê autochthon. The name Gufan comes from the Kaingang language and means "ancestor". For the integrity of the anatomical piece she proved to be the most apt to be reconstructed.

Dr. Parellada and Dr. Carneiro collected all the data about Gufan, as well as sent me a series of photos that served as a basis for 3D scanning by the photogrammetry technique. Shortly afterwards I had the skull digitized and the reconstruction work started.

Facial reconstruction

The process of facial reconstruction went smoothly with nothing new in relation to the other works. Starting with the positioning of soft tissue thickness markers, I then went through digital sculpture, retopo (simplification of the mesh), mapping and pigmentation, and finally the placement of hair and generation of images.

The base of facial texture

It must be documented that I received the mapping references with an international flavor. My friend Santiago González photographed one of his students in Lima, Peru and sent a series of images to be used at work. I take this opportunity to thank him and the student!

I had to resort to this solution because here in my city I did not have any individuals with indigenous traits to take pictures. I thought about it a little and turned to my Peruvian friends, since in that beautiful country, a considerable part of the population carries the appearance of its historic and warrior people.

The Virtual Reality

With the face of Gufan reconstructed I traveled to Curitiba where I would meet with the team to carry out our project. The works took place at the premises of Beenoculus, a virtual reality glasses assembly company and interactive content.

The excitement was so great that our workshop was just about creating a presentation for Gufan. Beenoculus donated a state-of-the-art goggles, my friend Binhara came in with cutting-edge machinery, a generous video card for the application to roll without choking, and Sandro Bihaiko wrote the application with the help of local officials.

While the presentation was developed on one side, we moved to the Paranaense Museum to see if everything was right with the space where the revelation would be held. A panel was assembled illustrating the stages of facial reconstruction, we talked about the distribution of the elements and seats and everything was right, just wait for the big day.

The face presentation

The presentation of the face of Gufan was held on January 24, 2016. Initially we expected 20 to 30 people, but I articulated a rapprochement with the press in order to supplant that number without much pretension, of course.

Before traveling to Curitiba I composed a release with the digital technology personnel and the management of the Paranaense Museum. I also telephoned several TVs and newspapers in the city and soon faced the biggest newspaper (Gazeta do Povo) and the biggest TV (RPC, Globo) showed interest in the agenda. The result of all this has been translated into two newspaper covers and a 7-minute story with two live insertions in the midday issue of January 24.

And during the presentation, instead of 20 or 30 people came 170 according to the organizers! A lot of people had to attend the two lectures standing. Total success!

Acknowledgment

I just have to thank everyone who made this possible: Claudia Parellada, Renato Carneiro, Alessandro Binhara, Sandro Bihaiko, Anelise Daux, Junior Evangelista Terrabuio, Rawlinson Terrabuio, Matheus Dalla, Victor Ullmann, Amilton Binhara, Adelina Binhara, Lucas Gabriel Marins, Durval Ramos, Angieli Maros, Fernanda Fraga, Keyse Caldeira, Caroline Olinda Everton da Rosa e  Karen Lisse Fukushima.

Not forgetting to mention the companies and institutions involved: Paranaense Museum, Azuris, Beenoculus, State Secretary of Culture of Paraná, Government of Paraná, Arc-Team Italy and all the press.

I hope from the bottom of my heart that this partnership continues and that good news the future holds. A big hug and thank you for reading!