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Aerial archaeology
method in the face of theory
W³odzimierz R±czkowski
Archeologia lotnicza - metoda
wobec teorii
Wydawnictwo Naukowe UAM, Poznañ
2002
ISBN: 83-232-1194-9
Summary
Contemporary archaeology is undergoing
dynamic changes. The process is largely a result of new theoretical concepts
being constantly developed but also a product of disappearing limitations
in international scientific exchange and easier access to up-to-date publications.
Consequently, there are favourable conditions in many countries to abandon
the principles of the widely criticized cultural-historical approach to
archaeology. A number of new works published apply novel methods and models
which are developed on the basis of new paradigms (specifically within
processual archaeology). Those methods and models are often supposed to
be a sign of the author’s original approach to archaeology but, in reality,
they merely mask the traditional approach. Empiricism, inductionism and
objectivity reappear in disguise. This practice reveals lack of theoretical
and methodological reflection.
Thus, it seems crucial that relation
between method and theory in archaeology is identified. The opinions on
theory and its role have undergone many significant changes. The same applies
to the method. Divergent concepts on the relations between theory
and method and a widespread belief among archaeologists that the choice
of method automatically presupposes the choice of theoretical orientation,
outline the important problem of the role method plays in theoretical approaches.
Questions about the reciprocal relationships between theory and method
remain ever topical. In scientific research there is a broad variety of
methodological options because the number of methods used in archaeology
seems virtually unlimited. There are methods of ground prospection, methods
of excavation, methods of describing and recording of archaeological material,
methods of explication and interpretation of past events, methods of studying
site formation processes, and many others. It is widely accepted that some
methods have no connection with theoretical thought whatsoever – they are
so to speak “theoretically neutral”. In my opinion, showing the mutual
relations between “theoretically neutral” aerial photographs and various
archaeological approaches may shed some light on the relationship between
theory and method.
Three conditions had to be fulfilled
before aerial photographs could become a useful tool for archaeologists.
Two of them were of technical nature: to be airborne and able to record
the surface of the ground from an elevated position. The third condition
required new thinking, recognition of the fact that archaeological features
and sites could be observed from certain altitude and that these observations
could be useful in addressing research problems. The two first conditions
had already been met by the time when archaeology emerged as a science,
which was in the middle of the 19th century, though the scientists of that
time did not recognise the usefulness of aerial photographs in the study
of the past. The dominating theory of cultural evolution steered archaeological
thinking of the past and its interpretations and it limited the scope of
interest, scientific problems and solutions. Applying the basic ideas of
evolutionism, archaeologists fully accepted the evolutionary-comparative
method, i.e. the comparison of cultural forms and states, and blatantly
disregarded their context. Consequently, they focused on chronological
problems, endeavouring to place cultural forms and phenomena within some
evolutional sequence. Aerial photographs could not be used for that purpose.
The military, however, showed an
early interest in “bird’s eye” views. From the very beginning they focused
on aerial photographs taken from balloons and used them for survey purposes.
The invention of the aeroplane in the early 20th century soon put balloons
in the shade. The First World War saw further development in terms of aircraft
and camera technology. Military air reconnaissance made the number of aerial
photographs taken explode. Undoubtedly, archaeological objects must have
been accidentally recorded at least on some of them.
The First World War also marks the
beginning of first and modest experiments with aerial photographs in archaeology
(e.g. L. Rey, T. Wiegand, G.A. Beazley, A. Poidebard), though it is widely
accepted in the literature of the subject that it was O.G.S. Crawford who
played the leading role in forming and formulating the principles of aerial
photography and making it known. Crawford’s recognition of aerial photographs
was based on theoretical foundations he had adopted in the first years
of the 20th century. At the beginning of his scientific career, Crawford
came under the influence of two mainstream trends in archaeology of his
times: evolutionism and diffusionism. The lecture he gave in 1911, The
Distribution of Early Bronze Age Settlements in Britain, clearly reflected
his theoretical thinking. Among the scholars who helped shape Crawford’s
ideas were P.J. Wiliams-Freeman, H. Peake and A. de Mortillet.
It is also widely accepted that Crawford’s
next lecture, entitled Air Survey and Archaeology and held on 12 March
1923, was the first scientific rendition of the new method. The main point
of the lecture was to establish the age and origin of lynchets he thought
to be of Celtic origin . The study was based on a detailed analysis of
stratigraphic data relations between a number of objects whose chronology
had been known . Crawford concluded that lynchets forming a mosaic of square
or rectangular fields had been introduced at the beginning of the La Téne
period (or even late Bronze Age) just after the first wave of Celtic migration.
The system was used until the Roman invasion. Narrow and stretched lynchets
were introduced by Saxon tribes and used until the end of the 18th century.
Crawford made some general remarks on aerial photography only towards the
end of his presentation, but he managed to show the benefits of the new
method and its applicability in solving research problems. The lecture
was on Celtic lynchets and aerial photographs provided for a penetrating
analysis of the issue. In sum, Crawford demonstrated the potential
of this method for archaeology presenting case study.
Crawford represented the evolutionist-diffusionist
school of thought in British archaeology, which was brought into being
in the early 20th century. It is not a difficult task to identify elements
of both theories in his work. Crawford aimed at establishing chronologies
of objects and arranging them in a chronological sequence. He made wide
use of metaphors, which was typical evolutionism. He stressed the importance
of analogy in the interpretation of spatial arrangements and in his explications
he referred to cause-and-effect relations. Discontinuity in the emergence
of new cultural forms was often explained in terms of migration. The geographical
method makes it possible to determine the origins, spread and boundaries
of a culture. In this approach opinions of a general nature were formed
on the basis of source archaeological data. The empirical nature
of Crawford’s scientific procedure let us believe that he fully accepted
the positivist notion: the greater number of sources (record, data), the
better and more complete our knowledge about the past. Crawford’s treatment
of sources (archaeological record , data) was very characteristic. He regarded
archaeological sources (record , data) as objective and physical objects
in which past world was preserved. The source (archaeological record, data)
is independent of the researcher who uses it to reconstruct past events
and cultures. It is static and passive like a fossil palaeontologists understood
it then. In this context Crawford considered aerial photographs to
be an objective representation of objectively existing archaeological sources
(record, data). In other words, he believed in what he saw and treated
photographs as a true rendition of the real world. He claimed that a photograph
registered everything an archaeologist could see with the naked eye. The
process of the reconstruction of the past world by means of photographs
requires the archaeologist to be passive and uninvolved. Observation is
reduced to ‘pure’ visual perception. The archaeologist is equipped with
an ‘innocent’ eye and ‘pure visual perception’ belongs to the canon of
empiricism. In such an approach to archaeology, an aerial photograph has
the same validity as other archaeological sources (record, data),.
Owing to Crawford’s propagating
skills, many followed in his footstepsCrawford’s activity soon gained many
adherents. They were both pilots, fascinated by the romanticism of the
journey into the past, and professional archaeologists. Since the very
beginning some tendencies dominated and influenced the future development
of the method and the ways it was perceived by archaeologists. Researchers
were divided into two groups: those who practised aerial archaeology, i.e.
the taking of aerial photographs, and those who used photographs in their
archaeological research. The first group consisted of amateurs who became
fascinated by the new method. They had enough financial resources, time
and flying skills to be able to make archaeological discoveries and “compete”
with professionals. Academic research owes to them a number of extraordinary
discoveries and scores of information on new archaeological sites. The
joy of discovery was accompanied by the reflection on the nature of soilmarks,
cropmarks and shadows. They played decisive part in developing improving
the methods of regular air reconnaissance and taking aerial photographs.
They behaved like collectors or antique dealers. Flights made it possible
to discover new sites and taking pictures of the sites was like collecting
objects.
Academic archaeologists soon accepted
aerial photographs as a tool of discovering and registering archaeological
sites. Field archaeology made aerial photographs one of the main methods
of site recognition applied prior to excavations. However, aerial photographs
were not regarded as equally important in solving research problems. Questions
archaeologists asked were limited to the chronology and spatial structure
of the site – the latter solely for the purpose of planning the excavations.
It seems that this qualified success
of aerial archaeology influenced the scope of the research questions asked.
The belief that archaeological material directly informs of the past limited
the archaeologist’s main interest to pure documentation of the site and
establishment of chronology. This sufficed to place the object in chronological
order and to “reconstruct” the past. Aerial photographs were gradually
limited to the initial phase of source requisition, i.e. to ground survey.
Suggestions to use photographs for map-making and problem-solving were
put in the shade.
The positivist approach to archaeology
limited the scope of questions that could be asked on the basis of aerial
photographs. On the other hand, aerial archaeology brought some new questions
with it and proposed new interpretations of traditional scientific problems.
In a series of spectacular discoveries new sites were identified (e.g.
Woodhenge), which made archaeologists reinterpret their views on many issues
related to the past. Aerial photographs also introduced a new perspective
to the studies of past agriculture: an analysis of the changeability of
field systems. C. Fox, clearly inspired by Crawford, gave rise to a new
trend called landscape archaeology, which chose aerial photographs to be
its key source of information.
The development of British archaeology
from the 1930s till 1960s diversified the ways the science was practiced
by introducing analytic methods from other sciences but also formed a certain
pattern of discourse in which such categories as object type, archaeological
cultures and groups, form of evolution, migration and diffusion played
a big part. Numerous discussions led gradually to a synthesis of different
theoretical reflections and to the emergence of a cultural-historical trend
which manifested itself by a variety of differently stressed elements of
functionalism, neo-evolutionism and Marxism.
The discussion in academic circles
had some impact on aerial archaeology. The way aerial photographs were
used changed considerably. J. Bradford, M. Beresford and J.K.S. St Joseph
took a turn towards the technological and economic interpretation of facts
registered on photographs. It resulted in the recognition of new classification
criteria, and consequently, shifted the focus of the debate to interpretation
and not description alone. Photographs became objects of analysis (equivalent
to written sources and maps in the work by Beresford and St Joseph) and
not mere illustrations.
Diffusionism made an important contribution
to the cultural-historical approach by introducing maps as a tool of archaeological
analysis. Bradford used maps not just for the analysis of distribution
but also in the studies of past landscape. A map did not only include cultural
elements from a given period or a given archaeological culture, but also
topographic elements important for a certain type of landscape (under the
influence of G. Clark’s ecological functionalism). In this way one could
study cultural objects in their relation to the past natural environment.
Analysing the fields of interests
of academic archaeologists, one can clearly see that they focused on the
studies of material culture and the technological and economic aspects
of culture. By the force of events aerial photographs were put in the shade,
far away from mainstream archaeology. Even Bradford’s, Beresford’s and
St Joseph’s splendid works, which opened up new scientific horizons (e.g.
landscape archaeology, medieval archaeology), could not reverse the process.
Aerial photographs were, however neither forgotten nor ignored. On the
contrary, in all major work on the general aspects of archaeology, aerial
photographs are considered one of the most important methods of prospection.
Even Crawford treated them that way towards the end of his scientific career.
It seems, however, that the first
years after the Second World War brought some regression in the application
of aerial photographs in archaeology. The establishment of the Cambridge
University Committee for Aerial Photography (CUCAP) and a collection of
aerial photographs in 1948 did not change the situation. St Joseph, curator
of the collection, carried out regular air survey of Great Britain but
he focused mainly on the discovery and documentation of archaeological
sites and published photographs in a very selective and schematic way.
St Joseph’s restrictive attitude towards aerial photographs did not help
disseminate the method in academic circles. Aerial archaeology became less
and less attached to the ideas and objectives of academic science.
The situation was similar in the
USA. Aerial photographs played marginal role and the American reflection
was very much the same as the British. Photographs were considered useful
in making detailed plans of sites. They were also applied to the identification
of field systems and, together with field studies, in the studies of economic
aspects of North American archaeological cultures.
Positivist objectivism, empiricism
and inductionism dominated archaeological thinking. This was clearly evident
in the attitude towards research practice and the separation of archaeological
data from their interpretation. The main aim of the archaeologist was a
possibly detailed and objective description of data. One needed to collect
all data available to be able to know the past. This empirical approach
made archaeologists concentrate on information and data collection. In
common thinking archaeology was perceived as synonymous to data collecting.
That is why so much attention was attached to methods used in field archaeology.
The more data one managed to collect, the better and more complete the
knowledge of the past was. This thinking provided the foundations for archaeological
conservation. One of its main aims and activities was the discovery and
registration of archaeological sites. This was especially important in
the formation of conservation policy after the Second World War.
The period after WW2 brought dynamic
economic activity aimed, among others, at the restoration and building
of cities, industrial facilities and roads. Consequently, many archaeological
sites came under threat. From the objectivist viewpoint, which was predominating
in archaeology, the destruction of sites was considered irrevocable loss
of information. The threat was recognized and expressed for the first time
in A Matter of Time. It offers a careful analysis of threats that archaeological
sites face due to the development of industry, communication, building
and agriculture and formulates the policy of the protection of archaeological
heritage. There was no controversy that protection of archaeological heritage
requires first of all a precise record of sites, their localisation, function,
chronology and state of preservation. Aerial photographs seemed to be the
most effective tool for that purpose. When the Royal Commission on the
Historical Monuments of England ranked aerial archaeology as one of the
most important methods in its programme of conservation, the science gained
momentum. The organisational structure was extended, enabling air reconnaissance
on a much larger scale and creating conditions for storing and accessing
photographs. It was also the next step in limiting the application of the
method to field archaeology. And since the conviction of the theoretical
neutrality of field studies was never questioned, aerial photography separated
itself from the methodological reflection in British archaeology.
It is widely assumed that New Archaeology,
later called processual archaeology, initiated a broad discussion on theory
and explication procedures in archaeology. The 1960s and 1970s, when processual
archaeology came into being, brought also a wide spectrum of technological
achievements into the humanities. The standardization of methods and the
repeatability of procedures fitted well into the belief of cognitive objectivity
and the possibility of formulating universal laws and general theories.
Methods borrowed from natural sciences were to guarantee the objectivity
of cognition.
Since the turn of 1960s and 1970s
aerial archaeology has been undergoing dramatic technological changes,
practically in every aspect. Aerial photography has been included into
a group of remote sensing methods. Remote sensing encompasses a variety
of registration platforms including satellites but also applies cheaper
methods of launching electromagnetic radiation registering devices (kites,
model planes, balloons). New devices have been designed to fulfil the need
to register different ranges of electromagnetic radiation. New methods
of data processing have been developed and computers have become indispensable.
This technological “revolution”
in aerial photography was possible mainly (though not exclusively) thanks
to processual archaeology. Processual archaeology stressed the necessity
of precise measurements of cultural and natural features and the objectivity
of the process, and thus opened up new possibilities to apply the potential
of aerial archaeology and import methods and equipment from other fields
of science (e.g. computers, GIS, satellite images). Processual archaeology
also viewed scientific problems from a new angle and helped formulate new
research proposals. New technology was supposed to serve the modern way
of practising archaeology. Consequently, the technological aspect is still
widely discussed among aerial archaeologists.
The variety of scientific issues
inspired by processual archaeology has resulted in a substantial widening
of the field of archaeological research. It has also influenced the way
aerial photographs are used in archaeology and how they are applied to
solving research issues. In aerial archaeology processual inspirations
(accepted more or less knowingly) have initiated dynamic and multi-faceted
discussions on various aspects of the method. It seems that processual
thought has substantially influenced such issues as a the concept of archaeological
source (record), the problems of classification and construction of models
describing the relation between cultural systems and natural environment,
and the application of technological achievements. Processual ideas are
also reflected in the issues connected with the protection and management
of archaeological heritage.
In aerial archaeology one can see
a continuation of fixed and widely accepted (in the cultural-historical
approach) patterns of thinking about the aerial photograph as an archaeological
source (record). Numerous publications on aerial photographs and on their
application in studies of the past treat photographs as equal to other
source categories. Though being specific in the way they are acquired,
aerial photographs undergo the same procedures as ceramic material found
during field survey or excavations. This, however, does not prevent archaeologists
from looking for distinguishing features that could help recognize archaeological
features or sites in the pictures. The basic indicators were already identified
by O.G.S. Crawford, Major Allen, D. Riley and J. Bradford. In the 1970s,
a need arose for a more precise explanation and systematisation of phenomena
that cause the appearance of cropmarks and soilmarks. There is a clear
relation between this requirement and Schiffer’s concept of formation processes.
Among aerial archaeologists, this way of thinking could have been inspired
by Schiffer’s ideas though it could also have resulted from the intensification
of aerial survey and the emerging research issues. It remains a fact that
within the realms of aerial archaeology, site formation processes were
vividly discussed. The reflection on the processes influencing the appearance
of distinguishing features that help recognize archaeological features
and sites on aerial photographs concentrated on three aspects: 1) role
of moisture, type of soil and plant species in the process of revealing
cropmarks, 2) forming of soilmarks and 3) discrepancy between research
results obtained by means of different methods (aerial survey, fieldwalking
survey, excavation).
The discussion on the factors forming
the appearance of archaeological features through cropmarks or soilmarks
and geomorphologic processes points to the growing awareness of postdepositional
processes. British archaeology concentrated on the processes which had
decisive importance for the formation of cropmarks and soilmarks. In American
archaeology, focus was put on the processes related to natural and cultural
phenomena which had an influence on the quality of archaeological material.
Classification plays a key function
in research process. The way classification was understood in cultural-historical
archaeology could not be accepted within the paradigm of New Archaeology.
The idea of a single, unique and ultimate classification of objects and
events was rejected. In fact, an archaeologist can apply many different
classifications. It depends on the problems and hypotheses he puts forward.
Classification is a ubiquitous practice in aerial archaeology. While analysing
aerial photographs, we have to order, group and identify cropmarks, soilmarks
or shadows. Few classifications refer directly to the postulates formulated
by processual archaeology. The efforts undertaken may be divided into two
groups: classifications which are stages of scientific procedures or studies
of the past and database classifications in institutions which are responsible
for collecting and disseminating information on objects from the past.
Solutions suggested by R. Palmer,
R. Whimster and D. Riley belong to the first group. In the version proposed
by Palmer and Riley, there is a clearly visible tendency to build a classification
for the purpose of solving a research problem. It does not differ much
from traditional ways of classifying (e.g. intuitive criteria, mixture
of morphologic and functional criteria) and does not aim at being universal.
The other group of classifications
includes efforts at recording and ordering the vast sets of information
included in aerial photograph collections and archives and making them
available. For years the objects visible in the photographs have been classified
according to intuitive functional and morphologic criteria. In the changing
circumstances a need arose to introduce a new set of objective categories
that could be used to describe new sites. The approach was necessitated
by the application of computers which allow building databases and by the
requirement of data standardization. In the solutions suggested for classifications
of large collections there are a lot of elements postulated by processual
archaeology like: objective class identification, isolation of a maximum
number of features allowing for “feature relation” analyses or numerical
taxonomy and the description of objects by means of metric data. The postulate
that this type of classification is indeed universal does not contradict
the opinion that there are no universal classifications. This type of classification
remains a certain standard of constructing and managing huge databases
and supplies us with pre-ordered material. It can be subjected to further
classifications when addressing a particular research problem.
Processual archaeology introduced
the term “model” being convinced that it could be applied as a tool in
scientific explication. Models are usually idealised representations of
reality. They serve as tools to present the results of observations or
hypotheses. They can also help visualise relations and structures of elements,
compare states of systems, inner structure of systems, explication procedures
and the construction and development of theories. Hypotheses play an important
part in explication procedures. They are generated on the basis of model-formulated
theories. Archaeologists must often choose which site or part of a site
is to be excavated. They have to decide what is going to be analysed and
why. It is no wonder that processual archaeology stresses the importance
of statistical sampling. Sampling enables a more economical disposal of
resources and time in preparation and execution of research studies. Still
more important is the belief that even a small fraction of a system is
representative of the whole since there are many regularities within any
cultural system.
The limitations of processual archaeology
influenced the American attitude towards sampling to a much greater extent
than the British archaeologists using aerial photographs. A correct method
of distinguishing test areas in regional studies was a necessary condition
for detailed analyses and allowed the results to be extrapolated on the
entire area of the study. Various sampling methods were applied in different
projects (e.g. Cedar Mesa Project, Lower Chaco River Project) and opened
up the possibilities for so-called predictive modelling. In both sampling
and predictive modelling, aerial photographs and satellite images were
used mainly to identify environmental and ecological factors. In each case
environmental variables were treated as independent. In this way they could
be measured and used in statistical analyses and the results could be generalised.
A systematic approach to culture enabled making conclusions (on the basis
of environmental variables) about cultural behaviours, especially with
relation to economic subsystems.
Predictive modelling was used in
many different ways. To a large degree it was connected with the intensification
and expansion of ground prospection. This had theoretical validity because
one needed to study several sites at a time to be able to understand the
intricate relations between human behaviours from the past. Efficient explanation
of past cultural systems requires that one studies the relations between
different places of human activity and residence at the time when the system
under consideration was functioning. The process that shaped the arrangement
of places of past activity was closely related to the adaptation of the
cultural system to geographical location. Thus, the spatial distribution
of sites, being the remains of economic behaviours in a given geographical
environment, may inform us of the organizational foundations of a past
cultural system. This theoretical approach directed the research towards
studies on individual settlements or camps (e.g. site catchment analyses)
or settlement studies (landscape studies) in the context of environmental
resources.
As in many other aspects, the application
of aerial photographs by American and British processual archaeology differed
substantially. R. Bewley, representing the British approach to processual
archaeology, uses aerial photographs in site catchment analyses to determine
the forms of ground exploitation by people from different settlements and
to build a model of settlement transformations and ground exploitation
methods. F. Findlow and L. Confeld (American version of processual archaeology)
have tried to establish the effects of settlement pattern influence on
environment close to an archaeological site by analysing LANDSAT satellite
images. The conclusions of the analysis point to the differences in soil
colours around sites and in places where there are no sites at all. In
this way one can define the criteria past societies adopted while choosing
areas for settlement.
In regional settlement studies led
by American archaeologists, aerial photographs serve to identify the features
of natural environment which past cultures adapted to. In the British approach
to regional studies (landscape archaeology), though also inspired by processual
archaeology, aerial photographs have a different function. The British
approach to landscape shows that aerial photographs and pieces of information
derived from them are used to build social-economic models within the system
theory. This necessitates precise mapping of all archaeological features
distinguished on photographs. And though archaeologists’ attention was
still focused on the analysis of sites in a settlement pattern, the results
often showed that one should not limit the analysis to a single site. The
breakthrough work by R. Palmer, Danebury. An Iron Age Hillfort in Hampshire:
an aerial photographic interpretation of its environs shows the change
in thinking and the transition to landscape studies. This change also brought
new reflection on the role of aerial photographs in the protection and
management of archaeological heritage.
Processual inspirations has also
found their way to conservation problems and, at least in some cases, they
were solved by means of aerial photographs. As in other aspects of processual
archaeology the American approach to the application of aerial photographs
in conservation activities was different from the British one. There are
multiple examples of how aerial photographs and satellite images were used
in conservation projects (Chaco Canyon, Green River Basin, Cedar Mesa,
San Juan Basin). Predictive models were used to plan conservation activities
on vast and weakly surveyed areas. Aerial photographs and satellite images
were applied to the classification of ecological zones, the choice of statistically
significant test areas and map making (also as layers in GIS software).
The strong relation between the concept of cultural resource management
and the concept of cultural ecosystems is deeply rooted in processual archaeology.
Less visible are the relations between
British archaeological heritage management and processual archaeology.
They manifest themselves in different activities and concepts, though they
are not unambiguously inspired by processual thought. Interesting in this
respect is the discussion on classification in aerial photography. It stresses
the belief that no classification is objective and correct and that classification
should be problem-oriented. This concept, however, contradicts the need
of data standardization, which is an obvious requirement in conservation.
The issue awoke warm discussions, specifically at the time when the guidelines
for the National Mapping Programme for England were being worked out. The
programme is perhaps the most obvious example of the influence of processual
thought on conservation policy in Britain. Projects done within the framework
of the programme put into practice those postulates of processual archaeology
that stressed the importance of precise spatial localisation of all observable
traces of human activities. In consequence, the maps made within the programme
are a splendid point of departure for all spatial analyses and processual
studies on past landscape.
Reflecting on the application of
aerial photographs in processual archaeology, one sees clearly that aerial
photographs are slowly being removed from the sphere of interest of academic
archaeology and taken over by institutions responsible for the protection
and management of archaeological heritage. The symptoms of this process
were already visible in the 1960s. It can be assumed that this was mostly
due to the participation of aerial archaeologists in theoretical discussions.
As long as O.G.S. Crawford stayed active, the main thoughts discussed in
the circles of academic archaeology were also reflected in aerial archaeology.
In the 1960s, 1970s and 1980s Crawford’s followers did not take up the
discussion and, in turn, aerial archaeology found itself outside the mainstream
of theoretical reflection. On the other hand, A Matter of Time moved the
stress of the application of aerial photography towards field archaeology
and conservation institutions. And theses aspects of archaeology were widely
considered theoretically neutral.
The emergence of some thoughts of
processual archaeology in aerial archaeology is an interesting phenomenon
showing the process of enriching archaeology with new ideas and reflections
without being directly connected with theoretical foundations. British
aerial archaeologists of the 1970s and 1980s were not completely isolated
from the world of academic archaeology where the main theoretical discussion
continued. The discussion brought about numerous works written in the spirit
of processual archaeology and the atmosphere within the science slowly
changed gradually influencing researchers working with aerial photographs.
The selective way in which processual reflection penetrated aerial photography
caused new ideas, methods and solutions to develop independently of theoretical
foundations. They were included in and enriched general commonsense knowledge.
Consequently, publications conceived within the framework of aerial archaeology
presented a mixture of ideas derived from both cultural-historical and
processual archaeology. The most characteristic trait of these publications
works was the application of various methods (without theoretical reflection),
also derived from processual archaeology (a phenomenon specifically typical
of cultural-historical archaeology). In effect, despite the application
of methods borrowed from processual archaeology, the final conclusions
were formulated in the spirit of traditional archaeology.
The picture of British archaeology
in the 1970s and 1980s, i.e. in the period when processual archaeology
was developing, is not uniform. Aerial archaeology had many “faces” at
that time. The tradition of collectors and antique dealers was still continued;
there were many works closely related to the cultural-historical trend
and some works and activities inspired by processual archaeology.
Processual archaeology directed researchers’
attention towards theory and this must be considered its great merit. Paradoxically,
it became the source of serious criticism of its main assumptions. By applying
various philosophical theories born within a wide stream called postmodernism,
archaeologists registered the limitations of processual archaeology. Modern
theoretical and philosophical inspirations in postprocessual archaeology
are so varied that they cannot be linked into a uniform theory.
Postprocessual archaeologists have
shown little interest in aerial archaeology. It seems however that there
is a hidden potential in it which entitles it to a broader participation
in scientific discussion. Postmodern thought can help us discover new layers
of scientific issues and fields of study in aerial archaeology. Aerial
archaeology must take a stand on the problems which are discussed by postprocessual
archaeology – the questions like a picture being text, the language of
aerial archaeology, and the problems of power and the concept of landscape.
In a traditional vision of the world
it is undisputable that we can only believe in what we see. “Pure” visual
perception is one of the canons of empiricism which is the dominating trait
of positivism. In postmodern thought, however, there is a belief that what
we see and what we do to perceive does not constitute part of innate and
natural abilities but rather is interrelated with the methods societies
shape knowledge forms, power strategies and systems of needs.
The essence of a photograph is to
confirm what it is depicting. One may have an impression that photography
(including aerial photography) is an ideal medium for an archaeologist.
It gives a direct image of the past and, outwardly, enables direct contact
with the past. But a photograph also immobilises our thinking of the past
and imposes a certain framework one can hardly avoid. We must also be aware
that aerial photographs are of a specific nature and they must be looked
at from that perspective. It is important to stress out that aerial photographs
do not (!) offer direct contact with the past understood as the reality
of past societies which are studied by the archaeologist. The past recorded
on the photograph is the past of air reconnaissance, a “fixed”, historical
image of soilmarks, cropmarks and shadows.
The complexity of photographing
processes and photograph interpretation can be looked upon from the perspective
suggested by R. Barthes. A photograph may be interpreted on the phenomenological
or semiotic plane. From the phenomenological point of view, the ability
of a photograph to authenticate is more important than the ability to depict.
A photograph is an image without codes and therefore it can be analysed
on the level of perception. However, the photograph is read through codes
which are culturally formed. The cultural functioning of a photograph is
only possible when it has been read. This is where the semiotic plane comes
in. Photographs do not include any “neutral” parts or elements which are
deprived of meaning. According to J. Piaget, there is no perception without
instant categorisation. A photograph is verbalised/narrativised at every
stage of perception. Moreover, it is perceived through verbalisation. It
means that a photograph is entangled in linguistic categories and this
statement has far-reaching consequences. One has to abandon the long-lasting
belief of cultural and theoretical “neutrality” of an aerial photograph.
Barthes’s views point to the cultural-social context of aerial photographs.
The social implications of aerial photographs are related to: (1) the stage
of taking photographs (especially oblique photographs), (2) interpretation
of the contents (both oblique and vertical photographs), (3) the use of
photographs (or rather their contents) to address research problems, (4)
the realisation of conservation policy and archaeological heritage protection
programmes, and (5) dissemination of the knowledge about the past.
Aerial photographs are closely connected
with text, in fact they are text. Their role as archaeological sources
(record) must be redefined. There is a need to create a special language
to analyse and interpret aerial photographs. This “language” is constituted
socially and changes in time and cultural context. One can say that “the
language of aerial archaeology” has been created since the times of Crawford.
Crawford was the first to tie the changeability of phototones in photographs
with the presence of archaeological sites on ground and then transformed
the information onto a map. This marked the beginning of the “language”
which has been undergoing constant changes since then and has been enriched
with new elements. This “language” constitutes our “reading” of the photographs.
Postprocessual archaeology has noticed
the social context of the archaeologist, his/her entanglement in his/her
own culture and his/her influence on the image of the past. The division
between the subject and the object of study has been questioned. Archaeologists
became interested in the relation between the past and their thinking of
the past. Since the notion of “truth” has also been questioned one could
not apply the criteria used by academic archaeology usurping the right
to form the only “correct” knowledge of the past. For a recipient, the
“true” image of the past is the one which is convincing and generally concurrent
with his/her ideas on the past.
Can aerial archaeology offer its
own “alternative” version of the past? It seems plausible. As far as popular
science is concerned, the output of aerial photography is considerable.
The market for popular books on the past has exploded and aerial archaeology
has found a niche for itself in the book trade. Aerial photographs are
the most valuable elements of such books enhancing the beauty of landscape
and historical monuments. They appeal to readers’ imagination. A photograph
seems to convey a neutral and objective message. In addition, it represents
reality and for the recipient it is the reality of past societies. As a
kind of archaeological source (record), it offers metaphorical contact
with past reality.
Let us conclude this review of the
methods of treating aerial photographs in different trends of archaeology
by answering the question of theory and method in archaeology. The examples
shown so far indicate that the concept of theory and method being independent
of each other must be rejected. There is a relation between theory and
method and this relation is not symmetrical. Research problems are formed
on the basis of theory and the problems are solved by means of different
methods. Thus, theory has a major influence on the place method takes in
research process. The questions we ask about method (inspired by our theoretical
knowledge) also influence the answers we receive. A method introduced to
archaeological studies at a certain point in time undergoes constant modifications.
It becomes more “specialised” and starts “living its own life”. Still it
is burdened with theory and practice it was “born” with. Many assumptions
remain deeply concealed. A certain model of interpretation is created from
the very beginning and hardly ever changes. Though method (and its results)
may occasionally influence theoretical assumptions, it is theory which,
to a much greater extent, governs the ways and the scope of method application.
Method cannot impose any theoretical approach but rather strengthen the
existing attitude or help develop a new one.
It seems necessary to analyse the
research process within archaeology. The process has changed through years
but it has shaped some standards of practising the science which, in turn,
are based on theoretical foundations (accepted more or less knowingly).
An analysis of theses processes may help us understand why scientific practice
has evolved the way it has evolved. It may lead to the deconstruction of
existing ideas, tasks and methods and may become the basis on which new
ideas, tasks and methods are formed. This can be called “metaarchaeology”
– a study of the discipline, its theories, methods and objectives. Methodological
selfreflection and deconstruction of existing standards are not synonymous
with negation. “Metaarchaeology” may rather widen our horizons by removing
limitations. We can enrich our understanding of the past by applying various
trends within archaeology. Cultural-historical, processual and postprocessual
archaeologies open up new fields of scientific exploration and deliver
multi-faceted images of the past. Nothing should make us think about the
past in the same and obligatory way. We must, however, understand the methodological
and theoretical foundations which influence our research processes. This
includes a careful selection of methods and adequate interpretation of
data we acquire.
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