Aerial archaeology with FLOS Hardware and Software

Hi all,

today I post an old presentation which I had no time to publish before. Its title is " Aerial archeology with FLOS Hardware and Software" and it is related with a lesson I gave during the Italian Virtual Heritage School 2013, held in Pisa at the headquarters of CNR. 

In my speech I tried to summarize Arc-Team's experience in aerial archeology from 2006 until July 2013. For this reason the slides are a little bit outdated, but the presentation still contains valuable informations for people who want to start with aerial related documentations with free and open source tools.

The first section of the slides is dedicated to an introduction about the two main component of our  Free and Open Source Remote Sensing Platform: ArcheOS (software) and an open source UAV (there are many option, like the UAVP, the ArduCopter, or the KK derivated copters).

The second part of the presentation shows the prototypes we built, both open source (UAV and KKcopter) and commercial (DJ Naza).

In the third branch I tried to summarize in a kind of "blueprint" animated infographic the main structure of a quadcopter. And later I simply repeated the post of ATOR in which Alessandro Bezzi described how to build an open source xcopter (KK board based).

In the fifth section are shown some possible quadcopters configurations, while in the sixth part is analyzed the evolution of the flight techniques (also considering different conditions that can influence the work).

Finally I presented some cases of study and, at the and, are just some tips based on our experience.

The presentation is embedded here below (just click on the window and press space to navigate). As usual in ATOR, it is released with CC BY, so if you need (also just some part of it), you can reuse the material in your work. I hope it can be useful.

For a better view, click here 

2016-04-26 Update

Thanks to self-archiving I can now add the bibliography related with this post:

 ResearchGate: Article

Academia: Article

I hope it will be useful, even if no more up to date it can be a starting point to work in Aerial Archeology with Open Software and Hardware.

Application of analytical chemistry in the early stages of an archaeological excavations

Analytical chemistry is the branch of chemistry that deals with the qualitative and quantitative identification of specific components called "analytes". It can be useful, in geoarcheology, to investigate the composition of the geological matrix of a given sample.

This science makes use of recognition techniques based on the reactivity and analyzes the tendency of a particular chemical species to react in the presence of specific reagents; in other words, under a practical aspect, it is possible to induce a reaction and to exploit its sensitive aspects to identify the presence or the absence of the analyte we are looking for.

During an archaeological excavation, it can be useful to know if, in the sediment we are removing, are present some components which can be considered as markers of specific past human activities. This kind of archaeological markers are organic substance, carbonates and phosphates and they may indicate the presence of paleosurfaces, middens, agricultural activities (like fertilization) or craftsmanship sites.

The organic substance is composed by chains of carbon, with oxidation state lower than +4, and hydrogen, that bind a number of heteroatoms (mainly oxygen, nitrogen, sulfur and phosphorus); the diagnosis involves the use of hydrogen peroxide [H₂O₂], as a liquid solution, which is poured directly on the soil sample; if some organic substances are present, they generate bubbles with effervescence; the more elevated is the organic concentration, the greater is the effervescence and vice versa.

The carbonates are chemical compounds which contain molecules made of a carbon and three oxygens [CO₃^2-] that bind other elements; the diagnosis involves the use of hydrochloric acid [HCl] in a liquid solution, poured directly on the sample. Also in this case, if the test is positive, it generates effervescence with bubbles (with a direct proportion with the carbonates presence).

This process is illustrated in the following video (H₂O₂ and HCl test from an old Arc-Team's excavation).

The phosphates are chemical compounds which contain molecules made ​​of a phosphorus and four oxygens [PO₄^3-] that bind other elements; the diagnosis involves the use of a reagent, in form of powder, consisting of ammonium molybdate [(NH₄)₆Mo₇O₂₄.4H₂O], antimony potassium tartrate [C₈H₄K₂O₁₂Sb₂.3H₂O] and ascorbic acid [C₆H₈O₆]; such a reagent is mixed with the solution of distilled water in which has been previously dissolved the soil sample: if some phosphates are present, the aqueous solution turns from azure to blue, depending on the concentration of this chemical element.
The process is illustrated in the following videos (phosphates test from an old Arc-Team's excavation):

1. Preparation of the soil sample

 2. Preparation of the analysis

 3. Reading the results

PS
For Italian readers, sorry for the jargon in the videos... everything is recorded from reality

3D PRINTING THE PAST: SOME ISSUES

Some weeks ago, Arc-Team and Kentstrapper (a Florentine startup that produces 3d printers) decided to collaborate, in order to make the Taung Child 3d model real, and possibly expose it in a museum.

But how does a 3d printer work exactly?

Basically a 3d printer uses the FDM (Fused Deposition Modeling) technique, an additive process where successive layers of material are laid down in different shapes; following a digital model of the object, the printer deposits layers of plastic material, automatically fused to create the final shape.

So, what we need first is a .stl model of the object. But (for now) not everything is 3d-printable: some spefic characteristics are required to be printed.

Which softwares can be used to locate and fix problems?

The most used software is Netfabb, that is not open-source neither free, but Netfabb Studio Basic can be freely downloaded.

In the Open-Source world, we can obviously use the 2 main 3d modeling softwares: MeshLab and Blender. In particular, in version 2.67 of Blender a 3d printing toolbox has been inserted as add-on: it's useful to check the mesh and see which are the problems. Pressing “Check All” a complete scan af the mesh will be done.

1. Volume: the mesh must be solid. It cannot have holes, 2-point polygons or single sided polygon surfaces.
2. Mainfoldness: the mesh must be completely and perfectly closed. The mesh must be “2-mainfold”: every edge must belong to 2 faces (not 1 or 3: only 2). Here are some reasons why a mesh cannot be 2-mainfold:

• Holes: Automatic hole-fixig can be made with Meshlab (Edit-Fill hole) or Netfabb; in Blender, from version 2.63 just selecting the vertices that “compose” the holes and pressing F in Edit Mode the missing face will be created.
• T-Edges: an edge cannot be on a board. In this case, the volume is considered open, even it seems closed. The face must be deleted and rebuilt (with the same method for closing holes).
• Internal faces: internal faces must be deleted, because they make the mesh “3-mainfold”.

3. Minimum wall thichkness: tipically a wall thickness of 2.5mm is required. The Blender toolkit can show the too-thin areas, that must be scaled till a proper dimension.
4. Polygon number: with too few faces the figure will lose detail, but with too many faces the fill will be heavy and possibilities of error will increase. To reduce the number of polygons of a mesh we should use MeshLab, following this tutorial.
5. Intersected faces: there may be 2 or more faces intersecting themselves, expecially in objects composed by two or more meshes. Even in this case, a solution should be remove the intersecting faces and then closing the hole with the method said.
6. Zero volume faces/edges: faces/edges with no volume.

So, here you can find the .stl file of the mesh. It's a really complex mesh, with an enormous number of faces and several problems (thickness, distorted faces); our goal is making it 3d-printable, and that's why we ask for your help. 

P.S. Thanks to David Montenegro for his suggestions.  

Remote sensing with UAV in archeology (lessons at Lund University)

Since 2011, Arc-Team is teaching during the course "digital archeology" at Lund University, introducing the class to the use of Free and Open Source Software (FLOSS) in archeology (with ArcheOS). The course is held by Nicolò Dell'unto (Department of Archaeology and Ancient History). 

This year we had the opportunity to give a lesson regarding the use of UAV (Unmanned Aerial Vehicles), and more precisely quadcopters,  in remote sensing projects. Our airfield was the Swedish village of Uppåkra, where the University is undertaking an excavation. 

Here you can see a coupe of video recorded in slow motion by our friends Carolina Larson and Stefan Lindgren of the Humanities Lab. Thanks to the slow motion, it is possible to observe the flight stability ...

... and the ability to maintain the position of the last drone we built (more details here).

The use of drones in the field of archeology has also attracted interest from the local press: the magazine of the University (LUM) published an article on the topic:

Radio-controlled helicopter maps
archaeological sites from above

The Faces of Evolution - Exhibition of hominids forensic facial reconstructions

May 18th through July 31st, 2013 will happen in the big and beautiful Curitiba city in Brazil, the exhibition The Faces of Evolution.

Near the replicas of skull of hominids will have nine panels with forensic facial reconstructions.

The exhibition will happen now, but the history started here in ATOR some months ago.

The methodology developed to model the majority of the faces was used for the very first time in Alberto di Trento's reconstruction.

On that occasion the Arc-Team presented a paper at the event Giovani Antropology (Italy), where they described the methodology for forensic facial reconstruction using only free software.

Following the events, we initiated Project Taung. If before we had rebuilt a modern human this time we would rebuild a hominid remote, then the Taung Child.

Beyond the Arc-Team Group, has joined the project Prof. Dr. Nicola Carrara University of Padua.

We were able to reconstruct the face of the Taung child fastly, thanks to a methodology developed previously.

We had a largely positive feedback, both personalities linked to forensic facial reconstruction, as those related to 3D modeling, as the creator of  Blender, Mr. Ton Roosendaal.

Several media outlets broadcasted stories (see the comments) on the reconstruction of the Taung child, as the Jornal de Brasilia above.

After the successful reconstruction of hominid remote, we got in touch with the archaeologist Prof. Dr. Moacir Elias Santos of the Archaeological Museum of Ponta Grossa and Prof. Esp. Vivian Tedardi of Rosicrucian and Egyptian Museum in Brazil and we began a series of modeling which culminated in the exhibition the Faces of Evolution, described here.

The Australopithecus afarensis.

The Homo erectus pekinensis.

The Cro-Magnon man.

The Turkana Boy.

The Homo heildelbergensis.

The Homo neanderthalensis.

The Homo habilis.

And last but not least, the Homo floresiensis.


This was a brief description of the exhibition and its history. Now, we expect the event date arrives, while others look for fossils to be rebuilt.

A big hug!

SfM for Underground Documentation

Since last October Arc-Team is working on a challenging project about World War 1 on the southwestern frontline 1915-18.

Austro-Hungarian artillery piece in wintry position 1916

In a few years we will celebrate the 100st recurrence of the Italian declaration of war against the Austro-Hungarian Empire in May 1915.
For that reason the South-Tyrolean Heritage Departement was starting an extensive archaelogical survey campaign in high alpine environment up to 3900 m.s.l.
We've had to find out a rapid, lightweight and low cost method to document the uncountable amount of structures along both front lines.
The area of our pilot project is an approximately 6 sqkm large high plane between 2000 and 2300 m.s.l. called Plätzwiese. Between 1915 and 1917 it was a strongly fortified second line artillery position of the Austro-Hungarian Army.

Crew Cavern

Because of the seclusion of this area, today there we can find some of the best preserved residues of WW1 in Europe. We expect a total amount of more than 1000 archaeological remains just in this sector.
One of the major challenges is the documentation of the numerous tunnels and caverns driven in to the rock to protect troops and material from enemy artillery fire.

View towards the exit

We apply SfM to obtain pointclouds of the interiors, dealing with difficult conditions of illumination and space. After placing GCP's around the entrance(s) and measuring them with our DGPS, we start with one or more sequences of pictures in the entrance area, advancing along the tunnels, turning at their end and coming back to the starting point.

In the dark we use of course a tripod to allow long exposures and some torches, to illuminate shadow areas.
In this way we've taken up to 300 pictures for one single structure.
Various attempts of processing them in Python Photogrammetry Toolbox divided in a few single sequences, gave us some indication of the most advantageous way of photographing.

Point Cloud in MeshLab v1.3.2.

For good results we need to follow two important rules:

1. Redundancy: The same point has to be visible in much pictures possible.
2. Long baseline: To obtain correct geometrical information, the projection centers of the sensors have not to be to close together.

• Taking a just a single photo-sequence along one way of the cavern, causes often problems with redundancy and subsequently lead to empty areas in the pointcloud, especially along the ceiling of the cavern.

Recording strategy 01

• Another of the experiences gained, is that the software has big difficulties to match features form the photo-sequence taken on the way inwards, with features from the photo-sequence taken on the way back to the entrance of the tunnel.

Recording strategy 02

• We get the best results advancing on two parallel lines, as well on the way in, as on the way out of the structure.

Final result 01

Finally we processed the parallel sequences of each direction and referenced them after in Cloudcompare in the way how Ale Bezzi described it.

Final result 02

In June 2013, after the thaw, we will resume fieldwork in Plätzwiese and we hope to  acquire further experience.

It is Carnival!

Once we were young and stupid, now we are no more young

(quote attributed to Mick Jagger)

OK, I am stupid, but the Taung Child face was the only 3D data I had in my computer at this moment, so I gave a try to a software we would like to add in ArcheOS.

We are working on the implementation of some new functionalities for the next release (Theodoric), especially regarding a good 3d engine and some augmented reality applications. I think Alessandro, surfing on the net, found the right open source software (openspace3d) and, with the help of ORNis (aka Romain Janvier) we hope to port it in GNU/Linux as soon as possible.

So here is the result of the first test:

Do not worry for the slow reaction of the software, it is mainly caused by the on-line screen recorder I was using to register the video (it was based on Java and it slowed down a little bit the applications that were running on my computer...). As usual, if you want to help us (also for software evaluation), just join ArcheOS channel on IRC.

Stay tuned :).

Arc-Team's UAVP: testing the NAZA dji

Hi all,
the "Arc-Team Air Force" acquires a new x-copter. After the:

1. Wolferl UAVP
2. Rolf R Bakke Multicopter from KKmulticopter.kr
3. Rolf R Bakke Multicopter from HobbyKing (work in progress)

we bought a NAZA dji. It is not a Open Hardware project, but a low cost solution to obtain aerial pictures. This drone has a perfect implementation of the GPS module and a revolutionary way of flight; it offers three types of control modes:

1. Manual (M) = manual free flight
2. Attitude (A) = free flight with altitude lock and high attitude stabilize
3. GPS = free flight with hold final position

The movie below show how the GPS works to hold the position till the remote control gives new moving command.

We didn't try yet the RTH (Return To Home); as soon as possible i will upload a new movie about it.

"A pig who doesn't fly is just an ordinary pig."

Marco Pagot alias Porco Rosso

(Hayao Miyazaki and Studio Ghibli copyright)

The Taung Child

Dr. Nicola Carrara, curator of the Museum of Anthropology at the University of Padua, sent us a note on the Taung project which we willingly share:

The Paleoanthropology is littered with nicknames assigned to various discovered hominin fossils: Lucy (Australopithecus afarensis), Mrs Ples (Australopithecus africanus), Ardi (Ardipithecus ramidus), Twiggy (Homo habilis), the Turkana Boy (Homo ergaster), The Hobbit (Homo floresiensis), the old man of Cro-Magnon man (Homo sapiens) are some of the most famous examples.

Naming the living beings is one of the tasks of Adam and Eve in the Garden of Eden. Giving a name to someone is the first way to know him, take him into our circle and, somehow, pigeonholing him.

But the name alone is not enough. To know someone, we also need to see his face. Name and Face are an inseparable pair to frame a person, so much that you go often in crisis when someone greets us, and we identify his face, but we can not remember the associated name.

Or, when you go back with memories, you feel uncomfortable with the fact that we remember the name of some people but not the features. Incidents of this type are common and show a fundamental process of our brain: we are better when we know a person's name and his aspect!

The Taung child (Australopithecus africanus) is a fundamental fossil in the history of Paleoanthropology. Discovered by Raymond Dart at Taung, South Africa, in 1924, the find consisted of the entire face, including teeth and jaws, and the endocranial cast of the brain. Dated between 2 and 3 million of years ago, the child was about 3 years old and had a cranial capacity of 410 cc, which would have been 440 cc in adulthood.

The fossil surprised the discoverer for the modernity of some of its features: the large and "rounded" brain, the small canines, different from those of apes, and especially the relatively advanced position of the foramen magnum compatible with bipedalism.

The cast of this fossil is in many museums around the world, and it's the evidence of the evolutionary history of our species. The Museum of Anthropology at the University of Padua keeps three copies of this find, along with those of many other Hominins.

When I was approached to join the "Taung" project, the first feeling was that of curiosity: I could finally know how the face of the child looked like, whose fossilized skull was in the closet behind my desk!

The curiosity was fueled by the various progresses of the work of Arc-Team that reached me through dr. Moreno Tiziani. Since a few weeks, the strictly scientific work of the team gave a face to the Taung child.

As an anthropologist and a curator of a museum, this result is very important. All the museography linked to human evolution is moving for some time to make our ancestors more human, taking away from the head the mistaken belief of the oneness of our humanity. There were many ways of being "human" and there have been many attempts to reach humanity. The Taung child is fully embedded in this story.

The times when the French paleontologist Marcellin Boule, between 1911 and 1913, reconstructing erroneously the skeleton of the Neanderthal of La Chapelle-aux-Saints, removed him from humanity because incapable, because of its anatomy, to "raise his eyes to heaven", are really far.

Today, thanks to the dedicated work of many scholars such as Arc-Team, when I open the closet behind my desk it's nice to see a familiar face.

Padua, december 4, 2012
Nicola Carrara

Translation: Moreno Tiziani

The flight of the penguin: eight years of ArcheoFOSS

I always liked this Linux commercial, it makes you believe that anything is possible... and, in a way, sometimes it is. 

When I think how the workshop ArcheoFOSS started, I find it incredible that it will reach its eighth edition.
It was 2005 and we were sitting on a table of Cafe Einstein in Vienna:

"The decision to start this workshop was taken one evening in November 2005 at Cafe Einstein (a few steps from Vienna town hall), during the conference “Archäologie und Computer 2005: Workshop 10” (Böener W., 2006), together with Alessandro Bezzi, Luca Bezzi and Denis Francisci of Arc-Team.
The idea behind the proposal to realize the workshop was mainly to take stock of the situation regarding the application of Free/Libre and Open Source Software philosophy to archeology."

[Introduction to the first workshop proceedings, Grosseto 2006 - edited by G. Macchi Janica and R. Bagnara]

Nevertheless, here we are! The eighth edition of ArcheoFOSS will be held in Catania on 18 and 19 June 2013, organized by Giovanni Gallo and Filippo Stanco of the Image Processing Lab (Catania University).

The elephant, symbol of Catania (and PostgreSQL)

To celebrate the event, I made a short video showing the path of the workshop from Vienna to Catania. It is a kind of "Fligth of the penguin" in archeology, through eight years and more than 3742 Km.

For FLOSS nerds, I made the video with OpenShot Video Editor, simply using the animate title option called "World Map" (thanks to Luca Delucchi for the tip!)
See you in Catania!

Young anthropologists meeting in Florence

Hi all,
just a fast post to advice that tomorrow will start the firts italian meeting of the "Young anthrologists" in Florence (September 13-14, 2012). The event is under the patronage of the AAI (Associazione Antropologica Italiana) and of the ISItA (Istituto Italiano di Antropologia); it will take place in the Anthropology Laboratories of the Department of Evolutionary Biology "Leo Pardi" (Florence University). Here is the official program of the conference. We (Arc-Team) will partecipate with a contribution of Cicero Moraes, Giuseppe Naponiello and Silvia Rezza ("A sperimental methodology of craniofacial digital reconstruction with FLOSS")  and during the final discussion about "Open Source e Open Data in italian anthropology and archaeology", with a presentation of Alessandro Bezzi and Luca Bezzi ("Anthropology and Open Source, the experience of Arc-Team".

The official logo

Master UNESCO Open Téchne: Open Source technologies for Cultural Heritage

In 2013 will start the first UNESCO master "Open Techne" (Open Source technologies for Cultural Heritage). The master is organized by the Istituto di Formazione e Ricerca della Federazione Italiana Club e Centri UNESCO e il Centro di GeoTecnologie (CGT) dell’Università degli Studi di Siena, with the aim to train professionals capable of using innovative open source technologies in the investigation and exploitation of Cultural Heritage. The registrations to the master are open until December 15, 2012.
More info are available on the official webpage: http://www.istitutoficlu.org/open-archaeo/.

We (Arc-Team) will partecipate to the master, teaching the use of FLOSS in archaeology and focusing the attention on ArcheOS. It will be also a nice opportunity to work together with Luca Mandolesi (adArte) and Enzo Cocca (CGT), developers of pyArchInit, to try to better integrate their tool in a specific deb package (untill now we added pyArchInit into an experimental ArcheOS package together with CADtools and BobMax's VTP extensions for QGIS).

Archaeological drawing from photomapping

IMHO one of the main benefits of photomapping is the fact that everybody is able to do good archaeological drawing. In this way it is not necessary to divide archaeologists between "diggers" (who simply excavate layer by layer)  and "drawers" (who just document). In our (Arc-Team) experience it is never a good solution when someone has to document a situation he does not know (because was exposed by someone else).
In other words, photomapping techniques and GIS allow also normal archaeologists to reach the same quality level of professionals in drawing layers or finds. As an example, the picture below shows the skeleton of a young goat found in Aramus (AM): the georeferenced photomosaic is done with photomapping techniques ("metodo Aramus") and the drawing is done by me (i am not a professional in drawing) using the GIS OpenJUMP (inside ArcheOS).

Georeferenced photomosaic and vector drawing with OpenJUMP