Institut für Raumbezogene Informations- und Messtechnik
Hochschule Mainz - University of Applied Sciences
Hochschule Mainz - University of Applied Sciences
 Zwischen dem RGZM und dem i3mainz besteht seit mehr als 20 Jahren eine enge Zusammenarbeit, die seit April 1997 im Projekt „Informationstechnik und Archäologie“ organisiert ist. |
 Mittels hochauflösender, dreidimensionaler Dokumentation unterstützt das i3mainz die archäologische Untersuchung von Petroglyphen. Verschiedene Aufnahmetechniken kommen zum… |
Optical recording of material cultural heritage (CH) is a multidisciplinary activity where the understanding of cross-disciplinary semantics is vital for a successful completion. In many cases, a lack of understanding of transdisciplinary semantics slows this process down. The end users who are mostly humanities experts lack the technical knowledge of spatial and spectral recording and could therefore demand more than what is actually required or sufficient for the intended CH application. The negotiations between technical experts and the end users are a tedious process. We present a semantic-based decision support system, COSCHKR, that employs reasoning and recommends optimal recording technology(ies) according to the application requirements of the recorded and processed data. COSCHKR is an ontology-based knowledge model that implies the development of semantic technologies within the Semantic Web framework. It represents formalized knowledge of the disciplines involved in the process of optical recording of material CH. The paper describes the applicability of the model in spatial, spectral, and visualization applications and summarises current possibilities and challenges.
2017
Moreau, L.,
Heinz, G.,
Cramer, A.,
Brandl, M.,
Schmitsberger, O.,
Neugebauer-Maresch, C.
This paper addresses the factors that conditioned the choices in lithic resource procurement for tool making at the Late Aurignacian site of Stratzing-Galgenberg (Austria), based on the lithic assemblage from the main area of the site. The raw materials used in the analysed assemblage are varied and partly relate to various local and non-local proveniences. The importance of non-local flint in the assemblage contradicts the distance decay model according to which the amount of a given raw material decreases with the increasing distance from its source. Drawing on the approach developed recently by Lucy Wilson, we examine the predictive ability of “source attractiveness” with respect to terrain difficulty and energy expenditure to understand why some sources were used more than others, using a Geographic Information System (GIS). Our results indicate that terrain difficulty and mobility costs matter and have a better predictive ability than Euclidean distance alone to explain assemblage variability in the Aurignacian of the Middle Danube region.
2015
Wefers, S.,
Cramer, A.,
Heinz, G.,
BrĂĽdern, R.,
Waldner, A.,
SĂĽrmelihindi, G.,
Passchier, C.,
Mangartz, F.,
Menchen, K.,
Gluhak, T.
A good documentation of archaeological excavations is of high importance due to the destructive characteristic of the process. Developments in technology and concepts allow new, often more effective approaches in the documentation process during excavation. Recording finds and features in their three-dimensional spatial distribution will aid at understanding the entire archaeological context after finishing field-work. Image-based documentation and 3D-scanning are valuable tools for preserving the site as a virtual excavation space on which informed archaeological analysis can be based.
The use of digital tools will result in manifold digital data representations. Especially these datasets must comply with certain specifications, such as formats, descriptions, meta information, etc. to be used in the long term, and thus be sustainable beyond the excavation project itself.
The meeting will deal with technological aspects of documenting the excavation, further archaeological processing, and data archiving.
Das Herstellen von Kopien bedeutender archäologischer Fundstücke hat eine lange Tradition am Römisch-Germanischen Zentralmuseum (RGZM) in Mainz. Der Artikel beschreibt kurz einige Verfahren und Möglichkeiten zur berührungslosen Erstellung von virtuellen Modellen sowie Kopien als Ergänzung zu den etablierten Verfahren. Anhand mehrerer Beispiele aus dem RGZM werden verschiedene Vorgehensweisen gezeigt. Die beschriebenen Beispiele sind mit den klassischen Methoden der Kopienherstellung nicht möglich. Beschränkungen bestehen noch in der Oberflächenqualität der 3D-Drucke, teilweise in der geometrischen Auflösung feiner Strukturen sowie der Farbe der Drucke.
At Mainz University of Applied Sciences, Department of Geoinformatics and Surveying, a long experience is available in co-operation projects with partners from the humanities for the purpose of archaeological and cultural heritage documentation and preservation. This paper focuses on a subset of about 40 diploma thesis which were executed within archaeological and cultural heritage documentation projects outside Germany. Besides the location of the project area, another selection criterion was the overall importance of diploma work for the respective project. While conducting such work in close co-operation with students and professionals of other disciplines, surveying students gain valuable knowledge from those other fields. In such projects, students of all participating disciplines have the chance to augment their disciplinary knowledge with knowledge from other disciplines.
As it is widely known documentation is an important issue within the tasks of conservation, preservation and restoration of Cultural Heritage objects. In this context high-tech measuring methods which, at the same time, are located in the low-cost price segment, are of special interest. In this paper a special solution is presented, which preserves the potential of state-of-the-art photogrammetry and is simple enough to be used by non-technical experts on their own. The design of the system enables, e.g., scientists of the humanities to benefit from modern 3D measuring methods in their daily work without needing permanent support by technical professionals. The system consists of off-the-shelf digital cameras which actually have reached a high level of resolution, of image quality and of functionality, all at a reasonable price. Ease of use for measuring purposes is guaranteed by mounting one or two cameras on a specially developed space bar. The corresponding evaluation software allows for stereo-viewing on standard PC hardware, for various methods of stereophotogrammetric model referencing, for object digitizing as vector features, for data export as CAD data, for production of orthophotos and of true-scale object representations of curved surfaces. Two projects are reported for illustration of the system’s application. The first project deals with the documentation of 500 caves in the Ukrainian area of Crimea, the second one gives an example for the application in the field of preservation of historical monuments in Germany. In both projects the stereophotogrammetric system was used as an integrated part within the full spectrum of modern metrology methods, comprising laser scanning, tacheometry, GPS and more.
The subject of this article is the geometric documentation of more than 500 caves cut into the soft rock of the plateau of Eski-Kermen, a medieval settlement on the highlands of the south-western Crimea. The types of caves and carved surface areas vary from very simple to extensive ones. A large number of traces and objects were recorded as basis for the understanding of the use of the caves, which were modified throughout the centuries until recent times. The aim of our sub-project is to develop a comprehensive system of effective geometric and archaeological documentation for further studies of cave settlements.
Using hybrid recording techniques is a well established procedure in the documentation of cultural heritage objects. Due to changes in the technological process, to choose the appropriate techniques and systems may be difficult and has to be adopted for every single project. The potential of new technologies sometimes tends to be overestimated whereas the need for especially adopted usage and processing may be underestimated. In combination with the needs of the appropriate and concerned historians or humanists the special requirements for the investigation and documentation of the objects have to be checked. The paper shows concepts and present results for several example sites in Germany e.g. the documentation of Porta Nigra, a roman city gate in Trier, and the Herkules-Monument in Kassel. Used techniques in the projects are 3D laser scanning, high resolution textured-light scanning, total stations, digital and analytical photogrammetry and high resolution digital surface images - all of them in combination with the conventional manual inspection and evaluation of the objects themselves by the particular experts from other disciplines.
Satellite imaging systems with spatial resolutions of one meter and less for panchromatic, and 2.5 to 4 m for multispectral images have become available in the recent years. Their images can match the quality of small scale aerial photogrammetry. This is of special importance to archaeology and cultural heritage documentation since it is often difficult to acquire suitable aerial photographs. Within an archaeological documentation project (the Tang Emperors' Mausoleums) in Shaanxi Province in the PR China, the authors used originally SPOT and LANDSAT
images. During the last decade, satellite images of higher spatial resolutions (IRS-1C, KVR-1000, IKONOS) from the region concerned could be evaluated and used for the documentation project. Examining the appearance of typical topographical details, it could be ascertained that the new products show a high potential for documentation purposes. The combination of local surveys with a background from satellite images and digital elevation models leads to a powerful documentation and visualization tool showing locations of artifacts and their relation to topography and geography. The use of GIS technology offers improved data access and query tools for the documentation of extensive archaeological sites.
3D scanning is a new technology which has proven to be well suited for a more efficient documentation in architecture, cultural heritage and archaeology by using 3D scanners. However, to obtain high quality results it is indispensable to control the whole data acquisition and data processing chain very much in detail. The paper will show how to apply laser scanning technology to objects of different kind and will include the demonstration of the achieved results.
In certain areas, such as the Middle Rhine Region in Germany, stone age artifacts can be found in large quantities on top soils of
farmland. Since more than 40 years amateur archaeologists, in cooperation with the Bodendenkmalpflege (curators for archaeological
monuments) in Mainz, are collecting these objects and store them, after registration, in their homes. In a joint research project,
archaeologists and engineers have developed a procedure to document these artifacts and make them available in a virtual collection.
A GOM ATOS II close range scanner, operating on a light pattern triangulation principle, is used to record a complete 3D point
cloud representation of the stones’ surfaces. Considerable effort has been taken to increase the speed of the recording process which involves the execution and combination of up to a dozen of scans from different aspects. Subseqently, the single scans have to be merged using two-dimensional and three-dimensional reference points. Following a 3D meshing procedure, the surface points are thinned. The 3D virtual object can be linked with a database containing further information such as material, usage, weight, place of present storage, etc. Coordinates for the locations where the objects were collected are also stored in order to create a GIS. Certain geometric properties such as size and volume can be derived from the virtual object and introduced into the database. This policy
makes the artifacts of the private collectors available to archaeological science and allows objective studies and comparisons. Interactive 3D visualization can be used to inspect and evaluate the artifacts when the data are distributed on digital data storage media. A special interactive viewer was designed for use in the Internet. Additional features such as visualization tools for local curvature and an automatic derivation of outlines for 2D drawings were developed in order to supply objective tools for inspection and publication.
Two statues of Pharaoh Pepi I. are the oldest known life-size metal sculptures in the world. They are dated to about 2300 BC and were excavated in 1897. In 2001, after a several years lasting process of restoration, conservation and technological investigation, the statues were documented geometrically. The shapes of the sculptures were recorded using a 3D laser scanner. Special features like the seams between the copper sheets forming the statue and the rivets connecting them were measured using close range photogrammetry. A model was generated from the scanner data as well as a 3D vector map of the line features from the stereo images. Besides these single results, both were combined for visualization purposes such as video sequences of the rotating sculpture or a combination with reconstructed vanished parts of the statue like the loincloth and the crown.
The geometric documentation of archaeological findings in excavations is expected to fulfil various demands. The work at the archaeological site shall be done in a short time, deliver accurate and impressive results which are easy to use and of high quality. And of course it is desired to be fast and cheap. This paper shows an approach in an excavation project in the PR China. The findings
had to be documented geometrically to be able to put them back into the original find position after conservation treatment. First results had to be available quickly after finishing field work. Finally, metrically correct plans are needed later on after the conservation. This is achieved by the combination of non-metric imaging techniques and standard close range photogrammetry. Results are stereo anaglyph images, simple rectified image maps (without using height information) and vector maps of the outlines
of the findings with discrete height indices.
The software tools needed in 3D scanning comprise a large number of modules. Software for scanner control is used to define which parts of an object are scanned at which resolution. Software for treating the huge data volumes of point clouds must allow visualization, data cleaning, filtering, point thinning and registration. If geometrically simple objects are encountered, software is used to fit primitives to the respective points. In the case of more complicated objects as they are frequently encountered in cultural heritage documentation, polygonal meshing is used to replace the surface by a mesh of small triangles. Meshing software must work in true 3D for these tasks and should be flexible enough to adjust to smooth surfaces and edges. Furthermore, it should be possible to map images onto the 3D meshes. A review of presently available software products shows that no ideal software product is available yet.
Satellite imaging systems with high spatial resolution have been announced for the near future. These images can match the quality of small scale aerial photogrammetry. This is of special importance to archaeology and cultural heritage documentation since many countries do not permit the use of aerial photographs pretending military reasons. Within an archaeological documentation project in the PR China, presently available high resolution satellite images have been evaluated for documentation and visualization purposes. The combination of local surveys with a background from satellite images and digital elevation models leads to a powerful documentation tool showing locations of artefacts and their relation to topography and geography. The usage of GIS technology offers improved data access and query tools for the documentation of extensive archaeological sites.Â
Ancient sculptures and findings play an important role in archaeological research. The survey of these objects includes information on size and shape. Digital object models can provide the basis for measurements, visualizations and copies, when the object itself is not available.
The object of the investigation is a copy of a Roman gravestone from the 2nd century AD. It has been chosen because it has different surface types with flat and steep, rough and smooth regions. Different methods are compared for their suitability to record these different types of surfaces.
Analytical and digital photogrammetric techniques have been used as well as systems designed for industrial measurements.
In the paper, the methods are compared with regard to efficiency and accuracy. Examples of the results and differences between the systems are shown.
Vermessungsaufgaben in der Archäologie betreffen sowohl einzelne Objekte als auch die topographischen Verhältnisse. Neben einfachen Verfahren stehen moderne Methoden wie elektronische Tachymetrie, satellitengestützte Positionierung (GPS), Photogrammetrie und Fernerkundung zur Verfügung. Um die notwendigen Messungen erfolgreich und wirtschaftlich zu bewerkstelligen, müssen in jedem Projekt die Einsatzmöglichkeiten dieser Verfahren geprüft werden.
Geo-Informationssysteme (GIS) bieten eine gute Grundlage zur Dokumentation ausgedehnter archäologischer Befunde. Dieser Artikel zeigt die Konzeption eines GIS zur Dokumentation der Tang-Kaisergräber in der VR China. Neben der Integration verschiedenartiger Daten steht die Bereitstellung dieser Daten für unterschiedliche Zielsetzungen im Vordergrund.
Die präzise und vollständige geometrische Erfassung von Objekten jeglicher Art wie auch deren Visualisierung und metrisch korrekte Abbildung ist eine der wesentlichen Aufgaben des Vermessungswesen (bzw. Geodäsie: Wissenschaft von der Ausmessung und Abbildung der Erdoberfläche). Üblicherweise hat man es dabei mit dem Objekt Erde (Geo-) und den damit fest verbundenen Teilen zu tun. Die Arbeitstechniken lassen sich allerdings auch auf andere Objekte anwenden, deren Oberfläche metrisch exakt beschrieben werden muß. Dies gilt besonders, wenn zur Vermessung digitale Datensätze gewonnen und rechnergestützte Verfahrenstechniken eingesetzt werden können.
Das vorliegende Beispiel dokumentiert einen Anwendungsfall, der die Einsatzmöglichkeiten von Vermessungsmethoden auf dem Gebiet der Archäologie beschreibt. Insbesondere stehen neue Techniken im Mittelpunkt, die hinsichtlich der Datenerfassung mit digitalen Bilddatensätzen und bezüglich der Objektpräsentation mit digitalen Vektor- und Rasterdatensätzen arbeiten. Die vollständige metrische und inhaltliche Beschreibung des Objektes erfolgt unter Verwendung eines digitalen Objektmodelles, das eine numerische Codierung der Oberfläche bedeutet. Zur Codierung wird eine große Menge einzelner, in der Oberfläche liegender Objektpunkte verwendet, deren Koordinaten vermessen und zusammen mit topologischer und Sachinformation in einer geeigneten Datenstruktur abgelegt werden.
Durch den so gewählten Lösungsweg wird die Anwendung auch zum typischen Beispiel für den Einsatz von Methoden der Geoinformatik, die benötigt werden, um Objekte in geeigneter Weise numerisch codieren zu können. Neben den zentralen Fragen der Datenstrukturen, der Verwaltung und des Umgangs mit objektbezogenen Daten spielen dabei natürlich auch die Vermessungstechniken eine wichtige Rolle, mit deren Hilfe die Objektbeschreibung gewonnen wird.
Der Aufsatz soll einen Einblick in diese Thematik geben und am konkreten Beispiel die verschiedenen Verfahrensschritte beschreiben.
All archaeological objects are related to geographic locations. No matter if these objects are removed or left in situ, their geographic location should be recorded. This paper reports about experiences using satellite images for the purpose of documentation and visualization in two different archaeological projects. The potential of established remote sensing systems, such as SPOT and LANDSAT, was examined being aware that systems with much higher resolution will be operational in the near future.
Using satellite images and digital image processing for the topographic documentation of archaeological sites leads to a reduction of time as compared to classical tacheometric surveys. To a certain extent, aerial photographs can be substituted, especially where not available. If processing is involved, special hard- and software and trained staff are necessary, however.
Perspective views, virtual flights, or reconstructions can give an improved imagination about the site and the surrounding topography to anybody.
If a common reference system is introduced, satellite images can be combined with other graphical and descriptive information and stored in a geographic information system (GIS) supplying a suitable data management system and user interface. The user of the system is able to formulate own data base queries and extract exactly the required information in written or graphical form.
For further publication and distribution of archaeological documentations, the use of multimedia systems is encouraged. Multimedia documents can be distributed on mediums such as CD-ROMs or the Internet and read without expensive software. As compared to a GIS, query functionality is limited to those links that are supplied by the author.
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Der Beitrag schildert die Möglichkeiten moderner Vermessungsmethoden für die Archäologie. Anhand von Beispielen aus der Dokumentation der tangzeitlichen Kaisermausoleen in der Provinz Shaanxi der Volksrepublik China werden die Möglichkeiten und Grenzen verschiedener Verfahren beschrieben. Für die Aufnahme einzelner Punkte kommen einfache Handvermessungsverfahren, elektronische Tachymeter oder Satellitennavigationsverfahren wie das Global Positioning System (GPS) in Frage. Soll mit einem Meßvorgang eine Oberflächenform in ihrer Gesamtheit erfaßt werden, so bieten sich Laserscanner, photogrammtrische Aufnahmen im Nahbereich, aus niedrig fliegenden Fluggeräten oder vom Flugzeug aus an. Schließlich bieten Fernerkundungsaufnahmen von Satelliten aus insbesondere dort Vorteile, wo größere Bereiche erfaßt werden müssen oder wo die Anfertigung von Luftbildern nicht erlaubt ist.
The eighteen mausoleums of the Tang Emperors (A.D.618-907), scattered over an area of about 5000 km² in the vicinity of Xi'an, the capital of the Province of Shaanxi, in the People's Republic of China, are presently documented in a joint Chinese-German project. The scales of the plans and maps to be produced extend from 1:2.5 to 1:1 Million. Consequently, a large variety of surveying methods is used, including close-range photogrammetry, tacheometry, GPS measurements, and remote sensing. For this reason, the purpose of this paper is not only a report about the specific project but also a review of possible solutions when geometric and topographic information has to be surveyed and visualized in archaeology.
The paper shows the conception and the achieved results for an archaelogical project aiming at the description and reproduction of a 3D surface body by means of digital photogrammetric techniques. Therein it is of main interest, to make full use of the 3D characteristic of the object surface. That means the collection, storage, organization and extraction of all discrete surface points as individual 3D elements within a unique 3D coordinate frame. The paper shows the actual stage of development, allowing for the complete description of the body surface and the use of the data for visualization purposes.
The data collection will be done by application of an image matching process onto each stereo model, resulting in a local Z=Z(X,Y) description. Due to the known geometric relation to the object bounded coordinate frame the local surface description can be transformed into a S=S(X,Y,Z) representation, taking some qualtity measures and geometrical parameters as additional attributes. Finally all transformed data sets will be merged into a unique object description, taking into account the supression or aggregation of individual point data within the overlapping areas.
As actual use of the surface data some graphical reproductions will be shown, using a selection process collecting all individual points which have to be considered, followed by the necessary geometric and radiometric transformations to achieve the desired surface representation.
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Boochs, F.,
Reich, T.,
Trémeau, A.,
Karmacharya, A.,
Heinz, G.,
Kato, Z.,
Tamas, L.,
Karaszewski, M.,
Gerke, M.,
Murphy, O.