Presentation: Glacial Archaeology in South-Tyrol

During the last "Frozen Pasts" conference, taken place in Innsbruck (A) from 12. to 16. October, we have presented - charged by the Cultural Heritage Department of South-Tyrol - the most important glacial sites discovered during the last 25 years in this region.

25 years ago, the dicovery of the iceman „Ötzi“ marked the beginning of a new discipline of archaeological research and cultural heritage preservation in South-Tyrol: The glacial archaeology.

Since than the Department of Archaeological Heritage has been focusing on several new high altitude sites, detected and reported exclusively by private persons: Leggings, socks and residues of shoes from the Iron Age on the Rieserferner (2.841 m Puster Valley).

For some years we have been investigating at the Langgrubenjoch (3.017 m Schnals Valley) remains of leather, pelt, and a wooden belt hook dating from the Copper Age, residues of a wooden building (roofing shingles made of larch) from the Bronze Age and other wooden findings from the Roman Age. Frequent visits to the main Alpine ridge since prehistory are documented by new finds on the Gurgler Eisjoch (3.134 m Schnals Valley).

Glacial archaeology meets modern conflict archaeology on the highest mountain group of the South-Tyrolean territory:

From the Stilfserjoch to Mt. Cevedale we have to deal with the remains of the frontline of WW1 between 1915 and 1918. Even the highest peaks like Mt. Ortler (3.905m) and Königspitze (3.851m) were permanently occupied by Austro-Hungarian and Italian mountain troops.

100 years later climate change uncover extraordinarily well preserved materials and structures which give us new insights into events and every day life on the high altitude positions.

Here is the presentation together with the live-recording of the talk.

QGIS - Reshape Features

This short Videotutorial shows you the effect of QGIS "Reshape Features" tool on vector lines.
If you have time to clean and smooth vector-lines manually, you can try that possibility.

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The Austro-Hungarian emplacements on top of Mt. Roteck

(2390m)

Dolomites / South-Tyrol 

 A case study for extensive survey and documentation on occasion of the 100th anniversary of the beginning of WW1 on the Italian front in May 2015.

As reported on ATOR in summer 2013, Arc-Team is pushing ahead the plan of  mapping extensive areas of the high alpine frontline of WW1 from the Swiss border to the Dolomites.

Our approach consists in a very detailed DGPS-survey, terrestrial structure from motion, geolocalized images, archeological description and aerial survey by our drone.

Of course we are basing the whole working process on Open Source Soft- and, where possible , also on Hardware.

Now we want to share the latest version of a presentation, given originally in occasion of the 7th Fields Of Conflict Conference in Budapest (Hungary) in October 18.-21. 2012.

It outlines the characteristics of the high alpine working environment, the nature of the WW1 remains, the challenges to meet, our project strategy and first results.

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.

From drone-aerial pictures to DEM and ORTHOPHOTO: the case of Caldonazzo's castle

Hi all,
I would like to present the results we obtain in the Caldonazzo's castle project. Caldonazzo is a touristic village in Trentino (North Italy), famous for its lake and its mountains. Few people know about the medieval castle (XII-XIII century) whose tower is actually the arms of the town. Since 2006, the ruins are subject to a valorization project by the Soprintendenza Archeologica di Trento (dott.ssa Nicoletta Pisu). As Arc-Team we participated in the project with archaeological field work, historical study, digital documentation (SFM/IBM) and 3D modeling.
In this first post i will speak about the 3D documentation, the aerial photography campaign and the data elaboration.

1) The 3D documentation 

One of the final aims of the project will be the virtual reconstruction of the castle. To achieve that goal we need (as starting point) an accurate 3D model of the ruins and a DEM of the hill. The first model was realized in just two days of field-work and four days of computer-work (most of the time without a direct contribution of the human operator). The castle's walls were documented using Computer Vision (Structure from Motion and Image-Based Modeling); we use Pyhon Photogrammetry Toolbox to elaborate 350 pictures (Nikon D5000) divided in 12 groups (external walls, tower-inside, tower-outside, palace walls, fireplace, ...).

The different point clouds were rectified thanks to some ground control point. Using a Trimble 5700 GPS the GCPs were connected to the Universal Transverse Mercator coordinate system. The rectification process was lead by GRASS GIS using the Ply Importer Add-on.

To avoid some problems encountered using universal coordinate system in mesh editing software, we preferred, in this first step, to work just with only three numbers before the dot.

2) The aerial photography campaign 

After walls documentation we started a new campaign to acquire the data needed for modeling the surface of the hill (DEM) where the ruins lie. The best solution to take zenithal pictures was to pilot an electric drone equipped whit a video platform. Thank to Walter Gilli, an expert pilot and builder of aerial vehicles, we had the possibility to use two DIY drones (an hexacopter and a xcopter) mounting Naza DJI technology (Naza-M V2 control platform).

Both the drones had a video platform. The hexacopter mount a Sony Nex-7; the xcopter a GoPro HD Hero3. The table below shows the differences between the two cameras.

As you can see the Sony Nex-7 was the best choice: it has a big sensor size, an high image resolution and a perfect focal lenght (16mm digital = 24 mm compare to a 35mm film). The unique disadvantage is the greater weight and dimension than the GoPro, that's why we mounted the Sony on an hexacopter (more propellers = more lifting capability). The main problem of the GoPro is the ultra-wide-angle of the lens that distorts the reality in the border of the pictures.
The flight plan (image below) allowed to take zenithal pictures of the entire surface of the hill (one day of field-work).

The best 48 images were processed by Python Photogrammetry Toolbox (one day of computer-work). The image below shows the camera position in the upper part, the point cloud, the mesh and the texture in the lower part.

At first the point cloud of the hill was rectified to the same local coordinate system of the walls' point cloud. The gaps of the zenithal view were filled by the point clouds realized on the ground (image below).

After the data acquisition and data elaboration phases, we sent the final 3D model to Cicero Moraes to start the virtual reconstruction phase.


3) The Orthophoto

The orthophoto was realized using the texture of the SFM's 3D model. We exported out from MeshLab an high quality orthogonal image of the top view which we just rectified using the Georeferencer plugin of QuantumGIS.
As experiment we tried also to rectified an original picture using the same method and the same GCPs. The image below shows the difference between the two images. As you can see the orthophoto matches very well with the data of the GPS (red lines and red crosses), while the original picture has some discrepancies in the left part (the area most far away from the drone position, which was zenithal on the tower's ruin).

4) The DEM

The DEM was realized importing (and rectifying) the point cloud of the hill inside GRASS 7.0svn using the Ply Importer Add-on. The text file containing the transformation's info was built using the relatives coordinates extracted from Cloud Compare (Point list picking tool) and the UTM coordinates of the GPS' GCPs.

After data importing, we use the v.surf.rst command (Regularized spline tension) to transform the point cloud into a surface (DEM). The images below show the final result in 2D and 3D visualization.

Finally we imported the orthophoto into GRASS.

That's all.

DVF vs FPV

Hi all,
I received some mails asking me to explain better the differences between the flying techiniques I mentioned in the previous post.
I think that the two videos you can see below are better than too many words to describe this topic. The clips were registered durig our last aerial archaeological project, thanks to the help of Walter Morelli (the pilot).
 
In this movie it is possible to see the normal way to fly with a quadcopter (Direct Visual Flight). The pilot simply uses the radio-command looking directly the drone, correcting the flight from his point of view. It is the basic flying techniques, but it can be difficoult when the UAV is far away from the pilot. In fact, in this situation, it is not simple to understand where is the front or the back of the drone.

In this other (very) short movie we can see the FPV technique (First Person View), in which the pilot, thanks to special glasses, has the same point of view of the drone. This way to fly is optimal when a low-altitude flight is not enought and it is necessary to send the drone far away from the pilot.   

I hope it was useful. Bye

UAVP (Universal Aerial Video Platform)

In 2006, during the Aramus Excavations and Field School, we had the possibility to partecipate in a subproject regarding the remote sensing of Aramus hill. The project was leaded by Ing. Klaus Kerkow with the help of Christine Hanisch. Luckily on that occasion there was the support of Armenian Ministery of Defence and of the Armenian Air Force, which provided an helicopter (as you can see in the picture), but, of course, this was an extraordinary situation.

The helicopter provided by Armenian Air Force

Since that year we tried to find a system to get remote sensing informations without the need of expensive or difficoult solutions (like helicopters or ultralight aircrafts). In 2008 we started a preliminary research which ended with the construction of an UAVP (Universal Aerial Video Platform), an open source UAV (Unmanned Aerial Vehicle). In the video below you can see the first flying test of our prototype (thanks to Wolfgang Mahringer, the main developer of UAVP project, who helped us in building our drone).