Archaeological Site Monitoring: Uav Photogrammetry Can Be an Answer

Abstract

ABSTRACT:During archaeological excavations it is important to monitor the new excavated areas and findings day by day in order to be able to plan future excavation activities. At present, this daily activity is usually performed by using total stations, which survey the changes of the archaeological site: the surveyors are asked to produce day by day draft plans and sections which allow archaeologists to plan their future activities. The survey is realized during the excavations or just at the end of every working day and drawings have to be produced as soon as possible in order to allow the comprehension of the work done and to plan the activities for the following day. By using this technique, all the measurements, even those not necessary for the day after, have to be acquired in order to avoid a 'loss of memory'. A possible alternative to this traditional approach is aerial photogrammetry, if the images can be acquired quickly and at a taken distance able to guarantee the necessary accuracy of a few centimeters. Today the use of UAVs (Unmanned Aerial Vehicles) can be considered a proven technology able to acquire images at distances ranging from 4 m up to 20 m: and therefore as a possible monitoring system to provide the necessary information to the archaeologists day by day. The control network, usually present at each archaeological site, can give the stable control points useful for orienting a photogrammetric block acquired by using an UAV equipped with a calibrated digital camera and a navigation control system able to drive the aircraft following a pre-planned flight scheme. Modern digital photogrammetric software can solve for the block orientation and generate a DSM automatically, allowing rapid orthophoto generation and the possibility of producing sections and plans. The present paper describes a low cost UAV system realized by the research group of the Politecnico di Torino and tested on a Roman villa archaeological site located in Aquileia (Italy), a well-known UNESCO WHL site. The results of automatic orientation and orthophoto production are described in terms of their accuracy and the completeness of information guaranteed for archaeological site excavation management.

THE INFLUENCE OF FLIGHT PLANNING AND CAMERA ORIENTATION IN UAVs PHOTOGRAMMETRY. A TEST IN THE AREA OF ROCCA SAN SILVESTRO (LI), TUSCANY

“…Moreover, these platforms represent a low-cost alternative to the classical aerial photogrammetry technique (Colomina & Molina, 2014;Irschara et al, 2010) The recent developments of the software for the Structure from Motion (SfM) and the continuous improvements of increasingly automated algorithms for digital photogrammetry brought to an intensive use of this technique in the last years. In addition, the reliability of these techniques in terms of precision and accuracy, for large-scale documentation purposes, has been already demonstrated by different researchers (Georgopoulos et al, 2016;Harwin & Lucieer, 2012;Rinaudo et al, 2012).…”

Fusion of 3D models derived from TLS and image-based techniques for CH enhanced documentation

“…This operation would have been quite unfeasible using only terrestrial survey techniques, since in architectural application the acquisition of data over certain heights need the use of an elevator, unless a minor resolution model is satisfactory. The RPAS tool employed in this application was a Vertical Take off and Landing 1.2 kg-HexaKopter (Mikrokopter), which is able to lift up to 1kg-playload (Figure 8) (Rinaudo et al,2012 According to the traditional rules of aerial photogrammetric acquisition, the flight plan evaluation, which entailed several calculations to achieve an adequate images overlapping for the later acquisition phase, was processed. This first step was developed using analytic calculations, considering a 50m-flying height, a 73,125x48,75 image format on the ground and a 80% along -50% across image overlap ( Figure 9).…”

Budget Uav Systems for the Prospection of Small- And Medium-Scale Archaeological Sites

“…Bendea et al, 2007, Eisenbeiss and Zhang, 2006, Grün et al, 2012, Rinaudo et al, 2012, Fallavollitaa et al 2013, Themistocleous et al, 2014, Tscharf er al, 2015. Making accurate documentation for excavation sites has a key meaning for methodology of archaeological research.…”