ARTICLE
GOOGLE EARTH AS AN ARCHAEOLOGICAL
TOOL IN THE DEVELOPING WORLD
AN EXAMPLE FROM INDIA
Tilok Thakuria, Tosabanta Padhan, Rabindra Kumar Mohanty, and Monica L. Smith
Tilok Thakuria is in the Department of History and Archaeology, North-Eastern Hill University in Chandmari (tilothakuria@rediffmail.com).
Tosabanta Padhan is in the Department of Archaeology at the Deccan College Post-Graduate and Research Institute in Pune (tpadhan@gmail.com).
Rabinda Kumar Mohanty is in the Department of Archaeology at Deccan College Post Graduate and Research Institute in Pune (rabikm@rediffmail.com).
Monica L. Smith is in the Cotsen Institute of Archaeology and Department of Anthropology at UCLA (smith@anthro.ucla.edu).
he use of satellite imagery for archaeological research has
dramatically improved the study of ancient sites and landscapes. Providing an aerial view, satellite images are an
outgrowth of the discipline’s early use of aerial photography.
Archaeologists in the early twentieth century eagerly adopted
the bird’s eye perspective to identify and document patterns of
human activity that were otherwise invisible on the ground,
such as the crop marks that indicated the remains of Roman villas in England in the pioneering aerial photographs taken by
O.G.S. Crawford in the 1920s. Given the costs of generating
original aerial photographs, archaeologists in the past two
decades have turned to satellite imagery to acquire a vertical perspective on archaeological landscapes (for comprehensive
reviews, see Fowler 2004; Parcak 2009:ch. 2).
T
their use. Commercial satellite images could cost hundreds of
dollars per frame, and archaeological projects often required
several images to cover survey regions (particularly when the
area of interest was in the corner of an image, necessitating the
purchase of adjacent frames). CORONA images are relatively
inexpensive, but many of the photographs are marred by cloud
cover and in any case the digitized images require sophisticated
processing to georectify prior to use. By contrast, the advent of
Google Earth has dramatically democratized access to archaeological landscape information worldwide (Ur 2006; Zukerman
2011). In developing countries such as India, satellite images
available through Google Earth have provided the scope for
archaeologists at both the student and the professional level to
make use of aerial imagery.
Archaeologists utilize satellite images for a variety of research
and monitoring purposes. Images can be used to examine areas
of the world in which field research is impractical or inadvisable
due to factors such as warfare and insurgency, landmines, and
problems of logistical or political access (e.g., for Afghanistan
see Thomas et al. 2008; for Cambodia see Evans and Travaglia
2012; for Egypt see Parcak 2009; for Iraq see Stone and Zimansky 2005; for Saudi Arabia see Kennedy 2011). Historical data
from the earliest satellite programs, such as CORONA images
starting in the late 1950s, can be utilized to evaluate landscapes
that have subsequently changed, providing archaeologists with
a more comprehensive palimpsest of ancient activities prior to
modernization (e.g., Ur 2003). Satellite images of more recent
date can be used to monitor destruction and changes due to
warfare, looting, flooding, deforestation, construction encroachments, and other adverse impacts.
As in the case of crop marks revealed through aerial photography to be the plans of Roman villas, satellite-based reconnaissance can detect patterns of human activity that are very difficult
to discern solely from ground-based survey, particularly in areas
of dense vegetation and modern human activities such as agriculture. Large-scale landscape modifications in the form of
mounds, embankments, and ditches often blend in with their
surroundings, revealed only when they are viewed at a much
larger scale and from a vertical perspective.
Until recently, however, the price of satellite images limited
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The SAA Archaeological Record • January 2013
Finding Walled Settlements in Eastern India
We present here a case of the use of publicly available Google
Earth satellite imagery to locate and identify archaeological sites
in eastern India. The current site-location project was an outgrowth of ongoing research at the ancient site of Sisupalgarh,
located in the eastern Indian state of Odisha (formerly Orissa).
Sisupalgarh is an Early Historic settlement, with the earliest
ARTICLE
Figure 1. A: Google Earth image of the walled Early Historic settlement of Sisupalgarh in eastern India with topographic overlay by G. Greene. B. Google Earth
image of the walled site of Talapada C. Google Earth image of the walled site of Lathi.
occupation in the mid-first millennium BC and continuing
until the middle of the first millennium AD.
Sisupalgarh was initially excavated in 1948, constituting one of
independent India’s first major archaeological research projects
(Lal 1949). Incidentally, the 1948 project also made use of that
era’s most sophisticated aerial-survey technology to illustrate
the perfectly aligned ramparts and gateways, an outline that is
still preserved in Google Earth images today (Figure 1a). The
rampart, measuring 1.1 kilometers square, has two formal gateways on each side, further identifying the construction as one
that was planned and executed on a massive scale.
tive administration. But there are no documents or other historical records that indicate the scope and extent of the political territory of which Sisupalgarh was a part, nor of the relationships
sustained between Sisupalgarh and neighboring population centers that comprised the Kalinga domain. Archaeological survey
in the region has been limited, with the majority of survey projects initiated by students and faculty working with very limited
budgets and the majority of Indian government-sponsored projects concentrating on the region’s extensive Buddhist sites.
Sisupalgarh has again been investigated in recent years in
which geophysical surveys and excavations focused on the social
and economic aspects of urban life in the Early Historic period
(e.g., Mohanty and Smith 2008; Mohanty, Smith and Matney
2007; Smith 2008). Throughout these investigations, Sisupalgarh was considered to be unique among the many walled
urban centers of the Early Historic period because of the regularity of the rampart. The site also has significant historical
importance, being associated with the third-century BC Kalinga
War whose catastrophic effects are credited with inspiring the
invading Gangetic ruler Asoka to renounce violence and lend
political support to the nascent Buddhist tradition.
The potential for evaluating the region’s sociopolitical integration
in the Early Historic period has been made possible, however,
through the use of Google Earth satellite imagery. In conjunction
with a survey at the Neolithic site of Golbai Sasan located 40 kilometers southwest of Sisupalgarh, R. K. Mohanty’s team encountered the site of Talapada on the opposite side of the river whose
surface artifacts were of the Early Historic period. In order to
examine the newly discovered site’s potential relationship to Golbai Sasan, team members utilized a laptop computer equipped
with a portable Internet connection to make a startling discovery:
the site of Talapada has a rampart and gateway configuration
identical to that of Sisupalgarh, but at a one-quarter scale (Figure
1b). Measuring 500 meters on a side, the site of Talapada has one
formal gateway on each side of the rampart, providing a duplicate of Sisupalgarh in both planning and execution.
The historical record, along with the size and configuration of
Sisupalgarh, clearly indicates the presence of a strong and effec-
The presence of identical material culture types and a replica
design of the rampart leave no doubt that Sisupalgarh and Tala-
January 2013 • The SAA Archaeological Record
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ARTICLE
ence 2011). Google Earth provides imagery that can be easily
accessed through desktop computers, laptops, and even cellular
phones in a manner that enables both pre-field and in-the-field
examination of geographic anomalies. When used in its mobile
form, Google Earth can be used as a background against which
to mark and label ground-truthed commentary on the location
and size of archaeological sites. Google Earth images, like other
satellite images, also can be utilized to identify geographic features associated with archaeological sites such as lake and ocean
coastlines and riverine paleochannels.
Figure 2: T. Padhan utilizing Google Earth on mobile telephone during field
reconnaissance.
pada shared strong social and political connections. Given the
existence of one subsidiary site, the team then began to use
Google Earth to systematically examine satellite images elsewhere in the region. Through this process, the team did identify
another location at the village of Lathi on the outskirts of the city
of Berhampur, located 150 kilometers southwest of Sisupalgarh.
Lathi’s outline indicates that the site was built on the same pattern as Talapada, and constitutes another example of a smallscale replica of Sisupalgarh’s urban plan (Figure 1c). Preliminary
investigations of this site confirm the presence of a rampart and
gateways, with artifacts of the Early Historic period that indicate
the site’s contemporaneity with both Talapada and Sisupalgarh.
Satellite reconnaissance in conjunction with ground-truthing will
continue in hopes of identifying other such sites. With the two
emplacements of walled settlements in the style of Sisupalgarh
now having been identified at Talapada and Lathi, however, the
potential for interpreting Sisupalgarh’s ancient territorial expanse
is already well-established. The discovery of these sites provides
an exciting new scope for research on urbanism, political economy, and territorial interactions in the Early Historic period.
Discussion
Google Earth has the potential to revolutionize survey data collection and analysis, with a few hours’ work on Google Earth
enabling archaeologists to find sites at a scale that would take
years using traditional ground survey alone (for comparable
transformative effects using LiDAR see Chase et al. J. Arch. Sci-
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The SAA Archaeological Record • January 2013
Although Google Earth is not as sophisticated for data analysis
as other forms of GIS and data collection, its low cost of acquisition (essentially free to anyone with access to a computer and
the Internet) and its coverage makes it particularly useful to
archaeologists working abroad. As Michael Goodchild has noted
(2008:20–22), Google Earth’s precision surpasses many developing countries’ official mapmaking services whose budgetary
constraints as well as national-security concerns often limit
researchers’ access to data. More recent additions to the Google
Earth repertoire, such as the “history” feature that allows users
to look at a decade’s worth of images from a single location, provides data that can be used to understand ongoing site-formation processes as well as documenting recent natural and
human-caused changes to archaeological sites.
Google Earth’s capacity to illustrate road overlays also should
not be underestimated as a logistical aid to fieldwork (Figure 2).
In rural India, road networks and signage are limited, and the
most practical method of finding one’s way around the landscape is to stop and ask residents for the best pathway to a point
of interest. Google Earth images facilitate those conversations
by providing a landscape perspective that is highly intuitive,
along with suggested road links. The team was continually
impressed by the ease with which local villagers, even those
with little or no formal education, could immediately identify
topographic features on satellite images.
Using Google Earth, the costs of field survey including vehicle
rental and surveyor time can correspondingly be reduced. For
many archaeologists in developing countries, transportation to
the field is the single greatest expense of research; any increased
efficiencies in site location can make a significant difference in
the size, scale, and duration of regional survey projects. In addition to identifying the location of potential sites that can be visited, Google Earth also can provide some indication of where
sites might be hypothesized to exist but where ground-truthing
is impractical or prohibited (for example, on military bases or
other government installations). The location of these “missing”
sites are critical for understanding ancient trade routes and
other networks, in which even the identification of potential site
locations adds robusticity to an overall regional model.
ARTICLE
Figure 3: The western gateway at Talapada, showing a slight elevation that in Google Earth is further enhanced by the presence of vegetation at the top of the rise.
Google Earth and other forms of satellite imagery do have some
limitations that are worth noting here. As in all aerial prospection, ground-truthing is necessary to ascertain the presence of
ancient cultural remains. Modern effects, such as recent construction and dismantling of sites, also may post-date the most
recent satellite activity. Although Google Earth does have some
three-dimensional capacity, slight elevations characteristic of
many ancient sites may not be visible except at ground level.
Vegetation such as trees planted on embankments may exaggerate linear features, making them appear more prominent in
satellite imagery than they are on the ground (Figure 3).
Anomalies in satellite imagery also can be difficult to interpret:
linear anomalies may either represent lower topography (such
as ditches) or elevated topography (embankments), while dark
and light areas can be the result of water accumulation, stone
outcrops, areas of burned vegetation, or anthropogenic soils.
Some types of sites will be more easily recognized than others
and our project’s focus on the distinctive perimeter ramparts of
Early Historic settlements constitutes an optimal research question for Google Earth site discovery (for similar discoveries of
fortified settlements using satellite imagery, see Parcak 2009:50;
Vega et al. J. Arch. Science 2011).
When topographic, historical, or colonial maps are available
they can be used in conjunction with satellite imagery to add
information about the likely source and chronology of modern
landscape modifications. Historical maps can sometimes contain anomalies that are not immediately visible on Google Earth
and vice-versa; when the goal is to locate previously-unknown
sites, a combination of all available data types is helpful. At
Lathi, for example, topographic maps illustrated just one Lshaped embankment, while the Google Earth image clearly
depicted an entire rectilinear outline with a moat and rampart at
the location.
Although Google Earth is free to use, the acquisition of highquality images for publications does entail costs that are at pres-
ent prohibitively expensive for many researchers in developing
countries (currently $399 per user per year, with a slight bulk
discount available for multiple users within a single project).
Google Earth does however offer some grants for educators to
be able to access the advanced features of the program including GIS data import and high-resolution printing.
Conclusion
As seen in our team’s discovery of previously-unknown fortified
settlements in eastern India, satellite imagery provides a quick,
inexpensive, and effective method for identifying anomalies for
further investigation. In the case of Talapada, Google Earth
imagery enabled the research team to make sense of a pattern
of construction that was otherwise difficult to read from the
ground. In the case of Lathi, the identification of a potential site
was initiated through a search of Google Earth images to match
patterns of known type in the landscape.
The widespread availability of Google Earth in developing
nations is providing a powerful source of landscape data for
archaeological research. In many cases, topographic maps can
be difficult to acquire for both logistical and political reasons,
with government mapping agencies citing the sensitivity of
international boundaries and coastlines as a rationale for limiting the distribution of printed exemplars. By contrast, Google
Earth is widely available, regularly updated, and can be accessed
in a variety of ways including at any local Internet kiosk for a
very modest hourly rate. This availability has the potential to
provide a new generation of students and scholars with powerful tools for site discovery and interpretation.
Acknowledgments. We would like to thank the Archaeological
Survey of India for the opportunity to conduct this research.
Support for the investigations described in this paper has been
provided by the Deccan College Post-Graduate and Research
Institute, Pune, and the Cotsen Institute of Archaeology, UCLA.
January 2013 • The SAA Archaeological Record
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The SAA Archaeological Record • January 2013
IN BRIEF
IN BRIEF, from page 3 <
tion Strategies, Archaeological Applications of Airborne Laserscanning to Improve Your Productivity by Using tDAR.
Meeting Abstracts
Just a reminder that the abstracts will be available electronically
to all on the public side of SAAweb approximately one month
before the meeting. They will be posted in a pdf format.
As in the past few years, there will be an abstract viewing center
onsite at the convention center in Honolulu where you will be
able to browse the abstracts.
2013–A Phenomenal Year!
Even though the year has hardly begun, it is shaping up as an
extraordinary one for SAA. Three major initiatives will be
launching this year:
• The SAA Online Seminar Series will be launching. Watch
for topics and times.
• Current Research Online will be debuting on the web.
• Advances in Archaeological Practice, the new journal, will premiere in August 2013.
Keep an eye on your email and SAA for details on these exciting
new initiatives!
Staff Notes
A 10-hour per week position has been added to the staff team as
of January 2013. Elisabeth Herschbach will be joining the staff
as Editorial Specialist. Her primary responsibilities will revolve
around the new journal, but she will have assignments touching
all of the SAA’s publications.
After a dozen years, John Neikirk, manager, Publications left the
Society on January 18 for an opportunity at another organization. I know that the membership will join the staff in wishing
John the best and thanking him for the legacy he has left to the
publications program.
Eleanor Umali joined the staff as the new manager, Publications
on January 21. Eleanor is a seasoned publications professional
with well-honed production skills. We expect that the publications program will continue to thrive under her management.
The coordinator, Membership and Marketing position has been
reinvented into the coordinator, Membership and Meetings
position. Alyssa Barnett, the staffer, will be taking on more
responsibilities specifically tied to the annual meeting in addition to the volunteer program.