Near Surface Geophysical Archaeological Prospection at the Prehistoric Site of Akrotiri on Santorini/Thera

In February 2014 high-resolution ground penetrating radar and earth resistance tomography measurements have for the first time been used successfully for the distinct mapping of buried archaeological structures in the vicinity of the Bronze Age archaeological site of Akrotiri on Santorini/Thera in Greece

Documenting Bronze Age Akrotiri on Thera using laser scanning, image-based modelling and geophysical prospection

The excavated architecture of the exceptional prehistoric site of Akrotiri on the Greek island of Thera/Santorini is endangered by gradual decay, damage due to accidents, and seismic shocks, being located on an active volcano in an earthquake-prone area. Therefore, in 2013 and 2014 a digital documentation project has been conducted with support of the National Geographic Society in order to generate a detailed digital model of Akrotiri’s architecture using terrestrial laser scanning and image-based modeling. Additionally, non-invasive geophysical prospection has been tested in order to investigate its potential to explore and map yet buried archaeological remains. This article describes the project and the generated results

Telecom quantum photonic interface for a 40Ca+ single-ion quantum memory

Entanglement-based quantum networks require quantum photonic interfaces between stationary quantum memories and photons, enabling entanglement distribution. Here we present such a photonic interface, designed for connecting a 40Ca+ singleion quantum memory to the telecom C-band. The interface combines a memory-resonant, cavity-enhanced spontaneous parametric down-conversion photon pair source with bi-directional polarization-conserving quantum frequency conversion. We demonstrate preservation of high-fidelity entanglement during conversion, fiber transmission over up to 40 km and backconversion to the memory wavelength. Even for the longest distance and bi-directional conversion the entanglement fidelity remains larger than 95% (98%) without (with) background correction

From deposit to point cloud: a study of low-cost computer vision approaches for the straightforward documentation of archaeological excavations

Stratigraphic archaeological excavations demand high-resolution documentation techniques for 3D recording. Today, this is typically accomplished using total stations or terrestrial laser scanners. This paper demonstrates the potential of another technique that is low-cost and easy to execute. It takes advantage of software using Structure from Motion (SfM) algorithms, which are known for their ability to reconstruct camera pose and threedimensional scene geometry (rendered as a sparse point cloud) from a series of overlapping photographs captured by a camera moving around the scene. When complemented by stereo matching algorithms, detailed 3D surface models can be built from such relatively oriented photo collections in a fully automated way. The absolute orientation of the model can be derived by the manual measurement of control points. The approach is extremely flexible and appropriate to deal with a wide variety of imagery, because this computer vision approach can also work with imagery resulting from a randomly moving camera (i.e. uncontrolled conditions) and calibrated optics are not a prerequisite. For a few years, these algorithms are embedded in several free and low-cost software packages. This paper will outline how such a program can be applied to map archaeological excavations in a very fast and uncomplicated way, using imagery shot with a standard compact digital camera (even if the images were not taken for this purpose). Archived data from previous excavations of VIAS-University of Vienna has been chosen and the derived digital surface models and orthophotos have been examined for their usefulness for archaeological applications. The absolute georeferencing of the resulting surface models was performed with the manual identification of fourteen control points. In order to express the positional accuracy of the generated 3D surface models, the NSSDA guidelines were applied. Simultaneously acquired terrestrial laser scanning data – which had been processed in our standard workflow – was used to independently check the results. The vertical accuracy of the surface models generated by SfM was found to be within 0.04 m at the 95 % confidence interval, whereas several visual assessments proved a very high horizontal positional accuracy as well

Quantum teleportation with full Bell-basis detection between a 40^{40}Ca+^+ ion and a single photon

We present several interface protocols between a single trapped atom and single photons from an entangled-pair source, among them the quantum teleportation of a qubit state from a single trapped $^{40}$Ca$^+$ ion onto a single photon. As appropriate Bell measurement, the teleportation protocol employs heralded absorption of one photon of the polarisation-entangled pair, which allows us to identify all four Bell states. Further protocols enabled by heralded absorption comprise quantum state mapping from a single photon to a single ion and transfer of polarization entanglement of a photon pair to entanglement between a single ion and the partner photon.Comment: typos corrected, acknowledgements adde

“BIG DATA” EN PROSPECCIÓN ARQUEOLÓGICA DEL PAISAJE

[EN] While traditionally archaeological research has mainly been focused on individual cultural heritage monuments or distinct archaeological sites, the Austrian based Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology goes beyond the limitations of discrete sites in order to understand their archaeological context. This is achieved by investigating the space in-between the sites, studying entire archaeological landscapes from the level of individual postholes to the mapping of numerous square kilometres. This large-scale, high-resolution, multi-method prospection approach leads to enormous digital datasets counting many terabytes of data that until recently were technically not manageable. Novel programs and methods of data management had to be developed for data acquisition, processing and archaeological interpretation, in order to permit the extraction of the desired information from the very big amount of data. The analysis of the generated datasets is conducted with the help of semi-automatic algorithms within complex three-, or even four-dimensional geographical information systems. The outcome of landscape archaeological prospection surveys is visually communicated to the scientific community as well as to the general public and stakeholders. In many cases, a visualization of the scientific result and archaeological interpretations can be a powerful and suitable tool to illustrate and communicate even complex contexts to a wide audience. This paper briefly presents the great potential offered by a combination of large-scale non-invasive archaeological prospection methods and standardized workflows for the integration of big data, its interpretation and visualization. The proposed approach provides a context for buried archaeology across entire archaeological landscapes, changing our understanding of known monuments. We address the overcome and remaining challenges with the help of examples taken from outstanding landscape archaeological prospection case studies.[ES] Aunque tradicionalmente la investigación arqueológica ha estado fundamentalmente centrada en monumentos y yacimientos arqueológicos de forma individual, el Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology (Austria) va más allá de los límites de yacimientos particulares con el objetivo de entender su contexto arqueológico. Esto es conseguido mediante la investigación del espacio entre yacimientos y estudiando paisajes arqueológicos completos yendo desde un hoyo de poste hasta el mapeado de varios kilómetros cuadrados. El enfoque de prospección multi-metodológico a gran escala y de alta resolución conduce hacia un enorme conjunto de datos digital que incluye varios Terabytes de información los cuales no habían podido ser manipulados hasta hace poco debido a limitaciones tecnológicas. Por consiguiente, nuevos programas y métodos de gestión de datos han sido diseñados para la adquisición y procesado de datos así como interpretación arqueológica para así permitir la extracción de la información deseada desde estos enormes bancos de datos. El análisis de estos conjuntos de datos generados es llevado a cabo a través de análisis de sistemas de información geográfica tridimensionales e incluso cuatridimensionales. El resultado de la prospección de paisajes arqueológicos es transferido de forma visual a la comunididad científica así como al gran público e interesados en la materia. En muchos casos una visualización de los resultados científicos e interpretaciones arqueológicas puede ser una herramienta más poderosa y adecuada para ilustrar y comunicar contextos arqueológicos complejos a un público mayor. Este artículo presenta de forma breve el gran potencial ofrecido por la combinación de métodos de prospección arqueológica de gran resolución a gran escala y unos flujos de trabajo estandarizados para integración, interpretación y visualización de datos. La estrategía propuesta proporciona un contexto para restos arqueológicos enmarcados en paisajes arqueológicos que viene a cambiar nuestra forma de entender monumentos ya conocidos. Pretendemos también superar los desafios que quedan con la ayuda de ejemplos sacados de excepcionales paisajes arqueológicos que son nuestros estudios de caso a prospectar.Torrejón Valdelomar, J.; Wallner, M.; Trinks, I.; Kucera, M.; Luznik, N.; Löcker, K.; Neubauer, W. (2016). BIG DATA IN LANDSCAPE ARCHAEOLOGICAL PROSPECTION. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 238-246. https://doi.org/10.4995/arqueologica8.2015.4200OCS23824