Abstracts:
Using GPR for archaeological surveys. How to conduct a state-of-the-art survey (and avoid the many pitfalls) (PDF zum Herunterladen)GPR
has been used in the field of archaeology for many years now. It is a
very quick and cost-effective tool for obtaining lots of data and gain
more insight in your site. Due to improved hardware, software and
computing power, both greater coverage and production of more
comprehensible display and interpretation is possible. Therefore with
increasing use of GPR and growing familiarity with techniques, it leads
to a fertile area for continuing innovation, commercial exploitation
and integration with other disciplines. Saricon uses GPR for
archaeological and geological surveys, as well as for utility detection
and singular metal objects (i.e. UXO’s).
Our view on how to execute a state-of-the-art survey by GPR:
Step 1:
First of all a good preparation (how obvious!)
What
are the right questions to ask regarding the aim of the survey, local
geology, soil and surface conditions? What system and settings will
give us the best quality? History of site? Positioning by GPS or local
grid? Define your research goals!
Step 2:
Site assessment, testing equipment and positioning.
Running
several test lines to get a ‘feel’ for the location but also get the
right settings. Don’t just flick on your equipment and start running
along your survey lines!
Step 3:
Processing data. Checking and
handling the raw radardata. Using filters to reduce background noise.
Building your 3D-model or timeslices. Groundtruthing if necessary.
Step 4:
What am I seeing??
Incorporating
other layers of information like results from previous surveys, aerial
photography, geological maps, information about corings etc… Discuss
model and refine interpretations.
Several examples with very different site conditions / research goals will be shown in our interactive 3D-model and discussed.
Ferry van den Oever GPR-operator SARICONIndustrieweg 152995 BE HeerjansdamThe NetherlandsFvandenOever@saricon.nl
Three-dimensional underground – The application of ground-penetrating radar in archaeologyGround
Penetrating Radar (GPR) investigates reflection characteristics of a
given material being under the influence of electromagnetic energy
waves. The fundamental properties of the respective medium – in
archaeology: the underlying soil and all objects included – are the
electrical conductivity and the magnetic permeability. When properties
change at the border of two bodies of different material (e.g. a wall
in dry sand) the energy is reflected partially. A sufficient contrast
regarding to the electrical properties of the different materials
allows the reflections of electromagnetic waves to be received by an
antenna.
To do a GPR survey two antennas – housed in one case ¬–
have to be moved across the area of investigation. One antenna
transmits electromagnetic pulses into the ground, the other one
receives reflected energy. Usually measurements are taken along
profiles the data is sampled to measurements of some few centimeters of
distance (e. g. 0.02 m). For archaeological purposes profile distance
should be less than 0.5 m. When electromagnetic waves enter a material
part of their energy is reflected at its interface and collected by the
antenna. GPR Data show a high resolution vertically and horizontally.
While the soil can be surveyed down to several metres, resolution of
the data decreases with increasing penetration depth.
GPR traces
every kind of material occurring in archaeological features (generally
soil and stone), but its use depends on the proper electrical
properties of the soil (depending on sea-son, hydrology etc.). It is
especially useful for surveys at sealed areas like pavement and in the
close vicinity of areas disturbed by recent human activity. In contrast
with other geophysical methods one could also use GPR inside buildings.
Among others the main advantage of using GPR is the ability to view
vertical sections and horizontal time slices in different depths. For
these reasons GPR is often applied to survey roman or medieval
buildings.
Martin PosseltPosselt & Zickgraf Prospektionen GbRFürthweg 964367 MühltalGermanyposselt@pzp.de
Hardware Aspects of the 16-Channel MAGNETO®-MX Magnetic Prospection SystemMAGNETO®-MX
vehicle-towed multichannel systems for magnetic surveying of large
areas have been in use for almost one and a half decades. In the past,
these system have been used internationally by commercial contractors
in unexploded ordnance (UXO) detection and in engineering geophysics.
Since 2008, MAGNETO®-MX systems are also being used for magnetic
prospection. With the new application, new challenges have to be met.
With
8 or 16 fluxgate vertical gradiometer magnetometers at sensor spacings
of 0.25 m or 0.50 m, MAGNETO®-MX systems cover a width of two or four
meters per track. Towed by a vehicle at speeds between 3 km/h and 15
km/h, this allows for a coverage of between 0.5 hectares and 3.0
hectares per hour, i.e. up to 25 hectares per day if ground conditions
allow. Driving at „high“ speeds of 15 km/h will result in coverage of
large areas at the cost of moderate, movement-induced magnetic noise.
Driving at slow speeds of 3 to 5 km/h will allow to cover medium areas
for detailed magnetic prospection with minimum movement-induced noise.
The
use of vehicle-towed MAGNETO®-MX systems allows to use geomagnetic
prospection not only on the scale of individual settlements or parts
thereof, but on the scale of landscapes and settlements in their
environments. During a project in Slovakia (Batora et al.), more than
100 hectares surrounding a bronze age settlement were surveyed with
0.25 m magnetometer spacing in less than 10 working days, resulting in
a detailed magnetic map of a bronze age settlement with ring ditches,
individual houses, pits, graves, etc. and the discovery of a neolithic
LBK enclosure and two roman period camps.
The application of
vehicle-towed systems requires users to rethink the approach to
magnetic surveying and to observe the specific properties of
vehicle-towed magnetometer systems in order to obtain high-quality
magnetic data. At the same time, the new application requires the
producer to meet new challenges and customer demands. The new
challenges encountered in the field of magnetic archaeological
prospection include:
• need for increased
sensitivity and resolution of the fluxgate vertical gradiometers at a
smaller measurement range,
• optimization of
carrier system to decrease movement-induced magnetic noise
(stabilization of sensor array carrier to reduce movement out of the
vertical during surveying), and
• need for specialized data processing and data interpretation tools
The
results produced so far show that fluxgate vertical gradiometers are
not inferior to scalar magnetometers such as cesium vapor magnetometers
as is often claimed. Both systems are subject to noise of certain
levels in real-world measurements; resolution of scalar magnetometers
decreases with sampling rate, thus rendering the alleged advantages of
scalar magnetometers ineffective. Comparisons show that the sensitivity
and resolution of fluxgate gradiometers are sufficient in all known
archaeological applications.
Literature:Bátora,
J., Eitel, B., Hecht, S., Koch, A., Rassmann, K., Schukraft, G. and
Winkelmann, K., in press. Fidvár bei Vráble (Kr. Vráble,
Südwestslowakei). Untersuchungen auf einem
äneolithisch-frühbronzezeitlichen Siedlungshügel. Germania (Zabern
Verlag, Mainz).Kay Winkelmann and Andreas FischerSENSYS Sensorik & Systemtechnologie GmbHRabenfelde 515526 Bad SaarowGermanykwinkelmann@sensys.de
Beneath the Palace of Knossos: preliminary results (PDF zum Herunterladen)This
is the presentation of the first results from a GPR (georadar)
prospective campaign that took place in May 2009, at the site of the
so-called Palace of Knossos, on Crete, Greece.
The entire fenced
area of the archaeological site, and some parts beyond the site were
prospected, with emphasis on the open-air and larger areas that could
be traced by the high accuracy GPS, which was mounted on the GPR.
The
initial phase of post processing of the geophysical data was done by
the external partner, who developed the GPR (Groundtracer/Direct
Contact). Here presented are the further processing phases that include
the integration of 3D geophysical imagery, with existing data. This
also demanded the rectification of the existing maps of the excavator
architects, aerial photographs, a Quickbird image and the existing
plans and profiles of test pits in the area.
These last are of
particular interest since they allow for a spatial connection between
newly measured geophysical features and anomalies and the
stratigraphically investigated features and anomalies in these test
pits. Since the test pits give us a vertical chronology of the entire
area, it is hoped that in time we can link all geophysical anomalies to
a measured chronology. We can then reconstruct a horizontal and
chronological layering of the entire site and therefore hypothesize on
the development of the site from the earliest phases till its
excavation.
Steven Soetens, Peter Tomkins and Jeffrey Horn Lopes
Institute for Geo- and Bio-Archaeology
Faculty of Earth and Life Sciences
VU University Amsterdam
De Boelelaan 1085
1081 HV Amsterdam
The Netherlands
steven.soetens@falw.vu.nl
Large-scale Geophysical Survey and
LiDAR at the Oppidum of Manching (Bavaria) – Perspectives and
Limitations of a Combined ApproachThe Oppidum of Manching
has been in the focus of European Iron Age archaeology for more than 60
years with excavations covering a total of c. 30 ha of its 380 ha
circumwalled interior. A vast variety of structures and features and an
immense spectrum of finds have lead to a considerably good
understanding of the settlement’s structural organisation and
development. Still, many questions remain to be answered. In order to
connect the different excavated areas the Roman-Germanic Commission of
the German Archaeological Institute conducts large-scale geophysical
survey within the oppidum and its adjacent surroundings. The
prospection revealed a large number of features which confirm and
supplement former results but also leads to a critical methodological
reassessment of the strength and limits of the application of magnetic
sensoring at Manching.
LiDAR was carried out in 2007 fostering a
detailed perception of the topography of the oppidum and ist
hinterland. It brought to light a number of previously unknown features
that have to be assigned to a local history of more than 3000 years of
human activity. Apart from new explanations the conjunction of
excavated features, geomagnetic data, aerial photography and LiDAR
shows that not every method readily detects expected and existing
features. Thus Manching, taking into account a specific geological and
geographical setting on a gravel terrace near the Danube allows for
advanced interpretations and the development of correlated strategies
of research. A comparative study of different methods of geophysical
research and remote sensing will reveal the perspectives and
limitations of a combined procedure.
Holger Wendling
Römisch-Germanische Kommission
Palmengartenstr. 10–12
60325 Frankfurt/M.
Germany
wendling@rgk.dainst.de
Sharpening our geophysical focus:
Making better models of the geophysical properties of archaeological
sites for prediction and interpretationGeophysical survey is
a valued archaeological tool, although the degree to which it is used
varies greatly between countries, regions and individual
archaeologists. The choice of geo-physical survey methods is rarely,
however, driven by a detailed preliminary appraisal of the site being
surveyed let alone numerical modelling of the kinds of geophysical
anomalies which the site might produce. This might not pose such a
problem if archaeologists and geo-physicists had a system by which they
accumulate experience of survey outcomes. They could then learn about
what geophysical methods work in particular sites and soils –
strengthening the choices of methods they make in future surveys. But
this is not the case. The formal analysis of the relationship between
geophysical survey results and excavated remains is rare. When it does
take place it is almost never accompanied by an analysis of the
geophysical properties of the remains in situ, during excavation.
It
would be useful to improve this situation by adopting formal standards
by which surveys are designed, and their results examined by a deeper
process of preliminary modelling and subsequent analysis. We lack,
however, agreed methods by which to collect such data. Moreover, we do
not have the numerical modelling and analysis tools which get beyond
the simple description of the geometry of buried remains and their bulk
geophysical properties to describe the underlying properties of buried
remains from which they are derived.
These issues impact directly on
the usefulness of geophysical survey methods to archaeology. They
challenge us to develop better computing methods, both to accumulate
past survey experience and to model site geophysical behaviour.
This paper will describe how such questions might be tackled and new computing methods which might be applied.
David Jordan
Archaeological Prospection Research Group
Institut für Geowissenschaften
University of Mainz
Johann-Joachim-Becher-Weg 21
55128 Mainz
Germany
jordand@uni-mainz.de
Augmenting Geophysics with GISGIS
has been employed in archaeological geophysics to display, overlay, or
integrate survey results with other sources of information, such as
Lidar, topographic maps, or satellite imagery, but its use remains
relatively low and its advanced manipulation, map algebra, modeling,
and decision tools are rarely employed. This presentation illustrates
how GIS can and should be integral to geophysical data management and
handling, advanced forms of display, data processing, analysis,
modeling, pattern-seeking, anomaly definition and identification. The
integration of geophysics with GIS is illustrated through several
example applications in the following domains.
1.
Registration, rectification & management of geophysical data are
illustrated through complex data sets that employ ground, air, and
satellite data.
2. Graphical display of data
demonstrates use of overlays, 3-dimensional views, transparencies,
color composites, and profiling.
3. Processing of
lateral survey data utilizes advanced GIS manipulation tools applied to
magnetic gradiometry, electrical resistance, and other data to form
site-wide composites of survey tiles, to balance apparent
discontinuities through "edge-matching" of means and variances, for
zeroing of traverses, for "de-spiking," for drift-removal and
"de-trending," for low- and high-pass filtering, and other techniques.
4.
Processing of 3-dimensional GPR data illustrates GIS resampling
techniques for stacking and distance normalization, background removal,
gaining, frequency filtering, time-to-depth conversion, extraction of
time-slices from profiles and their concatenation for horizontal plan
maps of subsurface reflections.
5. Modeling
approaches for integrating multi-dimensional data sets assume that
multiple geophysical data sets in concert are more informative than any
single data set, and are demonstrated through Boolean operations, map
algebra solutions, cluster analyses, and principal components methods.
6.
"Predictive modeling" of the subsurface follows from the foregoing but
employs regression methods to generate probability surfaces for classes
of subsurface archaeological features based on multi-sensor data inputs.
7.
Pattern recognition through template matching attempts to locate and
define anomalies of particular forms and sizes in aerial data sets
through comparisons against predefined shape templates.
8.
Knowledge-based decision modeling employs prior knowledge about
particular archaeological features and their geophysical responses and
utilizes measures of anomaly form, size, and relative spatial position
in several data sets to identify likely candidates for archaeological
feature types of interest.
Kenneth L. Kvamme
Department of Anthropology & Archeo-Imaging Lab
Old Main 330, University of Arkansas
Fayetteville, AR 72701 USA
kkvamme@uark.edu
Photogrammetry for documenting Heritage and ArchaeologyUntil
a decade ago photogrammetry was a quite exclusive, time consuming and
very expensive tool to document archaeology and heritage. The last 10
years the photogrammetric techniques evolved completely in the digital
direction and this as well in the image recording, the image processing
as well the end-products for the potential users. Where in the past the
photogrammetric techniques were unique for each image format, one can
say that the digital processing is image format independent.
All
these elements makes that photogrammetry became an excellent tool to
document heritage and archaeological findings. The digital way of
recording and processing makes the method a scientific and payable.
Also the digital photogrammetry is completely scale independent. The
presentation will contain examples of the documentation of:
-satellite images: to document archaeological sites as a whole,
-aerial pictures (vertical as well as oblique)
-archaeological excavations,
-building,
-objects.
The
full range of scales, which can be present in the archaeological
documentation, will be discussed with the geometrical precisions needed.
Rudi Goossens
Department of Geography
Ghent University
Krijgslaan 281
9000 Gent
Belgium
rudi.goossens@ugent.be
UAVs and remote sensing - early results of a geodetic approach (PDF zum Herunterladen)Assembled
and configured during a student's project one year ago, an octocopter
(MikroKopter MK-Okto) is serving educational as well as research
purposes at the University of Applied Sciences Mainz and it's research
institute i3mainz respectively.
The remote controlled unmanned
aerial vehicle can carry 1.3 kg along and is equipped with built-in GPS
locator that allows it to be programmed. In combination with a low cost
digital camera that can also be operated during the flight it offers
the possibility of collecting aerial photographs either of landscape
features or high building structures and allows several environmental
measurements.
One focus of the research conducted with the
octocopter is the photogrammetric use of the images. Especially the
automated processing of the image collections with “multi-stereo-view“
methods comprised promising results worthwhile also archaeological
applications. Two software-products, proprietary as well as open
source, have been tested concerning geodetic aspects such as accuracy
and precision of the processed data.
The presentation will detail
the construction of the octocopter and highlight several projects the
UAV was deployed already. It will also show the results of systematic
testing of the ground accuracy of the automated photogrammetric results.
Guido Heinz, Kai-Christian Bruhn and Jörg Klonowski
i3mainz
Institute for Spatial Surveying and Informationtechnology
University of Applied Sciences Mainz
Holzstraße 36
55116 Mainz
Germany
bruhn@fh-mainz.de
ifgicopter as a new mobile CIR Sensor Platform in Archaeology (PDF zum Herunterladen)Sensors
mounted on mobile platforms such as UAVs become less expensive and
light-weight components comsuming considerably less energy. This
enables to build UAVs for flexible monitoring and exploration of
territory, which can be inspected at very low costs with
high-resolution sensors. This was the starting point of the ifgicopter
project, which is based on a low-cost quadrocopter platform. Equipped
with a customized digital camera the ifgicopter is able to take Color
Infra Red (CIR) images „on-the-fly“. These CIR images can be used in
archaeological applications to identify patterns of plant covers. The
ifgicopter project is not only limited to cameras as sensors, but also
able to include other sensors for gathering environmental data (e.g.
weather data) based on a standards-based sensor protocol.
An additional part of the ifgicopter project is a software for flight
route planning with built-in features for automatic waypoint generation
based on inputs like an area of interest. The software is able to
extract based on a given flight route specific flight instructions to
automatically create stereo-image processing.
Matthes Rieke, Theodor Foerster
Sensor web, web-based geoprocessing and Simulation Lab (SWSL)
Institute for Geoinformatics
University of Münster
Weseler Straße 253
48151 Münster
Germany
m.rieke@uni-muenster.de, theodor.foerster@uni-muenster.de
Archaeological Use of Airborne Laser Scanning for Woodland Survey – Prospects and IssuesArchaeological
applications using ALS are increasing in number. Since the production
of the ALS-derived terrain models involves a considerable amount of
money, most applications use general purpose ALS data, which are
usually cheaper and sometimes even provided for free for scientific
applications. The main problem that comes with this kind of data is the
usual lack of meta-information. The archaeologist often does not get
the information about original point density, time of flight,
instrument used, type of flying platform, procedure of filtering etc.
Therefore, airborne laser scanning becomes a kind of “black box”, where
the derived DTM is used without further knowledge about underlying
technology and metadata. Therefore, there is a high potential that the
data used will not be suitable for the archaeological application.
Based
on the experience of a two-year project “LiDAR-Supported Archaeological
Prospection in Woodland”, the presentation will explain the basic
process of ALS, demonstrate its potential for landscape archaeology
especially in densely forested areas, and draw the attention to some
critical parameters of laserscanning, which should be known to the
user. Also, issues will be discussed, which need to be solved in near
future.
Literature:Doneus
M., Briese C., Kühtreiber T., Flugzeuggetragenes Laserscanning als
Werkzeug der archäologischen Kulturlandschaftsforschung. Das
Fallbeispiel „Wüste“ bei Mannersdorf am Leithagebirge,
Niederösterreich. Arch. Korrespondenzblatt 38, 1, 2008, 137-156.Doneus
M., Briese C., Fera M., Janner M., Archaeological prospection of
forested areas using full-waveform airborne laser scanning. Journal of
Archaeological Science, 35 (2008) 882-893.Doneus,
M., Briese, C., Studnicka, N., 2010. Analysis of Full-Waveform ALS Data
by Simultaneously Acquired TLS Data: Towards an Advanced DTM Generation
in Wooded Areas. In: Wagner, W., Székely, B., 100 Years ISPRS,
Advancing Remote Sensing Science. ISPRS Technical Commission VII
Symposium, Vienna, Austria, July 5 – 7, 2010. Papers accepted on the
basis of peer-reviewed abstracts. The International Archives of the
Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol.
XXXVIII, Part 7B, 193-198.
Michael Doneus
(1) LBI for Archaeological Prospection and Virtual Archaeology
Hohe Warte 38
1190 Vienna
Austria
(2) Department for Prehistoric and Medieval Archaeology
University of Vienna
Franz-Klein-Gasse 1
1190 Vienna
Austria
Michael.Doneus@univie.ac.at
The potential of LiDAR-based Digital
Elevation Models (DEM) and Local Relief Models (LRM) for the
archaeological prospection of large areas: methods and examples from
Baden-Württemberg (PDF zum Herunterladen)Since May 2009, the State Office for
Cultural Heritage Baden-Württemberg runs a project aimed at the
complete archaeological prospection of the federal state of
Baden-Württemberg (35.751 km
2) using high-resolution
airborne LiDAR data. The goal of this project is the verification and
extension of the existing archaeological database. The State Office for
Cultural Heritage is in the fortunate situation of having access to the
entire LiDAR dataset for the state of Baden-Württemberg.
Within one year after the start of the project, data processing had been completed and the prospection of approximately 4000 km
2
had already yielded more than 60.000 potential sites. This compares to
approximately 6000 previously known sites and find spots in the same
area. Most of the identified features can be related to resource
extraction and production (e.g., agricultural terraces, ridge and
furrow, kiln podia, mining and quarrying sites); others provide
information on transport (sunken roads), defence (ditch and rampart) or
funeral practices (burial mounds).
Due to the enormous amount of
data that have to be handled and processed in this project, the
importance of efficient data management is stressed and graphical user
interfaces developed for this purpose are presented. A methodology and
workflow for the extraction of local relief models (LRM) was developed
and is used as a tool for visualisation and morphometric analyses
(Hesse 2010). The utility of the LRM approach for archaeological
prospection is shown using various examples from the first results of
the project. Possibilities for spatial and topographic analyses of the
mapping results will be illustrated.
Literature:
Hesse,
R. (2010): LiDAR-derived Local Relief Models (LRM) – a new tool for
archaeological prospection. Archaeological Prospection, 17, 67-72. DOI:
10.1002/arp.374.
Ralf Hesse
State Office for Cultural Heritage Baden-Württemberg
Berliner Strasse 12
73728 Esslingen am Neckar
Germany
Ralf.Hesse@rps.bwl.de
Redefining Limits – The (Invisible) Future of Archaeological Aerial Reconnaissance (PDF zum Herunterladen)Being
the study of all sorts of archaeological remains by using information
acquired from a certain altitude, “aerial archaeology” encompasses the
entire process from the acquisition of imagery to the mapping and the
final interpretation. To date, the majority of source data used by most
aerial archaeologists are still acquired from a low-flying airplane
using small- or medium-format handheld cameras, capturing oblique
images. This non-invasive approach easily yields interpretable imagery
with abundant spatial detail, is extremely flexible and cost efficient,
but has the drawback of obtaining pixel data solely in the visible
spectrum.
Although beyond-visible information is produced by a
several space- and airborne multi/hyperspectral sensors, most users
lack the financial and staff resources to acquire and process such
data. Moreover, the spatial and temporal resolution of this imagery is
generally inadequate for archaeological research.
This paper will
present two new approaches to overcome the aforementioned constraints.
The first one relies on the use of modified consumer digital still
cameras to capture invisible radiation. The resulting imagery often
allows enhanced acquisition of archaeologically induced growth stresses
in crops (the so-called crop marks), while still maintaining the
flexible and low-cost approach characteristic for archaeological
reconnaissance. A second approach will look into the future of
hyperspectral scanning, an expensive technique that acquires data in
hundreds of small spectral bands. Even though airborne hyperspectral
imaging holds a huge potential to look at hidden archaeology, most
imagery generated are not archaeologically rewarding because of the
insufficient ground-sampling distance (being generally over 2.5 m).
Using real-world examples, this paper will indicate what
archaeologically-relevant hyperspectral datasets should look like.
Besides, necessary technical background will be provided in order to
understand why beyond-visible imaging and a high resolving power are of
the utmost importance in aerial archaeological research.
Geert Verhoeven
(1) LBI for Archaeological Prospection and Virtual Archaeology
Hohe Warte 38
1190 Vienna
Austria
(2) Faculty of Arts and Philosophy
Department of Archaeology
Ghent University
Sint-Pietersnieuwstraat 35
9000 Gent
Belgium
Geert.Verhoeven@UGent.be
Discovering The Dutch Mountains: An
Experiment With Automated Landform Classification For Purposes Of
Archaeological Predictive Mapping (PDF zum Herunterladen)Archaeologists routinely
rely on geomorphological maps to predict the location of archaeological
sites, and to understand their location in the landscape. In the
Netherlands, the availability of nation-wide LiDAR-based DEMs has
highly increased the level of detail of the available information on
landform. The mapping techniques used however are still the same as
they were in the 1960s: visual interpretation of elevation maps and
aerial photographs is combined with field visits to draw the maps. A
classification system developed in the 1970s (Ten Cate
& Maarleveld 1977), using an amalgam of geomorphometric and
geomorphogenetic criteria, is then used to perform landform
classification. This procedure is subjective and highly time-consuming,
to the effect that high-resolution DEMs have only been ‘translated’
into geomorphological maps for some parts of the country (Koomen &
Maas 2004), and are still only available on a 1:50.000 scale in order
to guarantee compatibility with the older mapping. Archaeologists
however are also interested in the small detail that is visible at the
1:10.000 scale, as the location of archaeological sites often seems to
be tied to relatively minor elevation differences and small landscape
units. Therefore, they tend to create more detailed geomorphological
maps of their own making for predictive mapping purposes.
Automated
landform classification has developed into a new branch of
geomorphological science that has the potential of quickly creating
highly detailed landform maps for large areas (see also Hengl &
Reuter 2009). Most published case studies however consider mountainous
areas, and the small elevation differences are often neglected. In
order to see whether these new approaches might be used to effect in a
relatively flat landscape, and save time in creating landform maps, an
experiment was carried out with two different techniques for automated
landform classification: image segmentation (Drăguţ & Blaschke
2006) and the unsupervised nested means method described
by Iwahashi & Pike (2007). These were then compared to a
visual interpretation of the DEM.
Literature:
Cate,
J.A.M. ten & G.C. Maarleveld, 1977, Geomorfologische kaart van
Nederland schaal 1 : 50 000. Toelichting op de legenda, Wageningen /
Haarlem.
Drăguţ, L. & T. Blaschke, 2006, Automated
classification of landform elements using object-based image analysis
Geomorphology 81, 330-344.
Hengl, T. & H.I. Reuter (eds), 2009,
Geomorphometry. Concepts, Software, Applications, Amsterdam
(Developments in Soil Science, Volume 33).
Iwahashi, J. & R.J.
Pike, 2007, Automated classifications of topography from DEMs by an
unsupervised nested-means algorithm and a three-part geometric
signature, Geomorphology 86, 409-440.
Koomen, A.J.M. & G.J.
Maas, 2004, Geomorfologische Kaart Nederland (GKN). Achtergronddocument
bij het landsdekkende digitale bestand, Wageningen (Alterra-rapport
1039).
Philip Verhagen
Research institute for the heritage and history of the Cultural Landscape and Urban Environment (CLUE)
Faculty of Arts
VU University
De Boelelaan 1105
1081 HV Amsterdam
The Netherlands
jwhp.verhagen@let.vu.nl
Lucian Drăguţ
Department of Geography and Geology
Salzburg University
Hellbrunnerstr. 34
5020 Salzburg
Austria
The erosion of a Neolithic enclosure site at Ottenburg (Belgium) (PDF zum Herunterladen)The
Ottenburg enclosure site is located in the Belgian loess area on a
peninsular plateau of c. 90 ha, about 50 m above the valley bottom of
the Dijle River. Archaeological research has been carried out on the
site from the early 20
th century onwards and includes two
small-scale excavations and an extensive fieldwalking survey. The
project presented in this paper aimed to evaluate the historical and
current erosion at the site. For this project both the (now) standard
and a high resolution LiDAR based DTM were made available by the AGIV
(Flemish Agency for Geographical Information Systems). The DTMs were
compared and evaluated in view of the identification of anthropogenic
features. Historical erosion rates were evaluated by an extensive
augering survey and current erosion and sedimentation patterns were
modelled.
Bart Vanmontfort and Anton Van Rompaey
Eenheid Prehistorische Archeologie
Katholieke Universiteit Leuven
Celestijnenlaan 200E
3001 Leuven
Belgium
Bart.Vanmontfort@ees.kuleuven.be
Reconstructing barrow landscapes: The construction and modification of Digital Elevation ModelsIn
recent years Digital Elevation Models (especially with the advent of
LiDAR-based data) have frequently been used in the study and
reconstruction of barrow landscapes. In most cases DEMs are used
unmodified and studied ‘as is’ as proxies of past landscapes. Two
aspects however influence the study of barrow landscapes and the DEMs
usually used in these studies.
The first aspect primordial to the
use of DEMs in barrow studies is time. It must be realized that barrows
have a long use-life. From the earliest barrows built in the early
third millennium BC right up till the 9
th Century AD barrows
were still being constructed. It is imperative in the study of barrows
that the evolution of the landscape in these 4000 years is understood.
Next to that the internal chronology of the barrows built in that
landscape must be understood to a large extent. Which barrow came first
and which came last? And where were they placed?
The second aspect
is vegetation. It is generally accepted that barrows were built in open
landscapes, sometimes interpreted as clearings in a forest (especially
for the oldest barrows), but the question remains as to how open these
landscapes were, how large were these clearings? Through the work of a
fellow Phd in our project we try and recreate the landscape all the way
through the 4000 years of barrow construction and see how it influences
and changes the landscape and the placing of barrows within that
landscape.
Both these aspects then influence any further study of
barrow landscapes. Through a few case studies it will be shown how
these factors significantly influence the interpretation of barrow
landscapes. Through the modification of DEMs, it will be attempted to
account for these factors and come to a better understanding of barrow
landscapes.
Quentin Bourgeois
Faculty of Archaeology
Leiden University
Postbus 9515
2300 RA Leiden
The Netherlands
q.p.j.bourgeois@arch.leidenuniv.nl
Satellite-assisted Archaeological Survey in the Silvretta Alps: the First Steps (PDF zum Herunterladen)The
universities of Zurich and Konstanz recently initiated a joint project,
titled Silvretta Historica, that aims at investigating prehistoric
relics of Alpine pasture economy (Alpwirtschaft) in the Silvretta
mountain range on both sides of the Swiss-Austrian border (Reitmaier
ed. 2010). In this project, fieldwork above the tree line is intended
to serve as case study for satellite-assisted archaeological survey
(Lambers, Reitmaier 2010), an emerging field in which exiting new
developments in terms of sensor technology, data analysis, and
integration of different data and methods are currently taking place
(De Laet, Lambers 2009). The Alpine environment of the Silvretta region
provides special challenges as well as chances for archaeological
survey. The terrain is rugged and difficult to access, weather
conditions are harsh, and archaeological relics are sparse and often
badly weathered. On the other hand, they are neither covered by trees
nor threatened or destroyed by modern land use. Some typical features
share common properties that facilitate their detection in images,
either directly or by proxy, using partially automated approaches. For
example, due to well-fertilised topsoil ancient herding sites are often
indicated by a special vegetation mixture called Lägerflora, that can
be detected through spectral classification. Cattle enclosures are
usually located on rare patches of flat terrain that stand out in
digital elevation models generated from stereo images or in slope
layers derived from them. While we hope to employ these and other
semi-automated methods in later stages of our project, we here describe
the first steps including image acquisition and pre-processing, dGPS
measurements of ground control points, and preliminary archaeological
fieldwork. This is expected to demonstrate the potential of
satellite-assisted archaeological survey in an Alpine environment in
which to our knowledge it has not been used before.
Literature:De
Laet, Véronique & Lambers, Karsten 2009: Archaeological prospecting
using high-resolution digital satellite imagery: recent advances and
future prospects - A session held at the Computer Applications and
Quantitative Methods in Archaeology (CAA) Conference, Williamsburg,
USA, March 2009. AARGnews 39: 9-17.Lambers,
Karsten & Reitmaier, Thomas 2010: Silvretta Historica:
Satellite-assisted archaeological survey in an Alpine environment.
Submitted to: Contreras, Francisco & Melero, Javier (eds.),
Proceedings of the 38th Computer Applications and Quantitative Methods
in Archaeology Conference, Granada, Spain, April 6-9, 2010 (in press).Reitmaier, Thomas ed. 2010: Letzte Jäger, erste Hirten: Hochalpine Archäologie in der Silvretta. Zurich: University of Zurich.Karsten LambersInstitute of Archaeology, Heritage Science and Art History University of BambergObere Karolinenstraße 896045 Bamberg Germanykarsten.lambers@uni-bamberg.deThomas Reitmaier
Dept. of Prehistory
University of Zurich
Karl-Schmid-Str. 4
8006 Zurich
Switzerland
t.reitmaier@access.uzh.ch