| Dr.
Marco Giardino
Chief Technologist, Engineering &
Science Directorate,
NASA's Stennis Space Center, Mississippi
Using high-tech remote sensing methods, a collection of artifacts
has been unearthed at Stennis Space Center near Bay St. Louis,
MS. The objects uncovered during archeological excavations conducted
over the past 11 years were found at the site of the 19th century
Hancock County seat on the Pearl River, which is now part of
the space center. Dr. Giardino was one of the archeologists
involved in the dig.
NASA Tech Briefs: Why is NASA conducting archeological
excavations?
Dr. Marco Giardino: The site is part of the
space center's buffer area and is therefore one of the cultural
resources that we are mandated to manage in line with federal
and state legislation. It is a preservation and conservation
effort on the historic resources that we own.
NTB: How was NASA technology utilized during
the excavation?
Dr. Giardino: While the ground-penetrating
radar was not developed at NASA, the application of it is innovative
from NASA’s point of view. We combine high-resolution
satellite and aerial imagery with a series of non-destructive
ground remote-sensing technologies, which includes the ground-penetrating
radar. In addition, we innovated the ability to take historic
documents, typically surveys and plats [chart or map of a piece
of land], and co-register them to modern imagery. The combination
of these three sets of data – the data satellite airborne
imagery, ground-penetrating radar, and the historically registered
plat documents – give us a much better indication of where
to dig, what to preserve, and what to avoid.
NTB: How was the remote-sensing technology
more beneficial than other archaeological methods?
Dr. Giardino: For a site that normally has
not been investigated, you have to do a sub-surface survey using
an auger or a shovel, and dig a hole every so many feet or meters.
In large areas, like the town, this is a very expensive and
time-consuming effort. Utilizing the three layers of data mentioned
before, it becomes much easier (especially when equipped with
a GPS) to go out into the site and identify those areas of particular
interest for investigation. For instance, we know from old newspaper
articles and an old plat where the hotel was located. The hotel
is of significance because of the person who owned it and the
artifacts that could be found in it. Once you have that information
on your computer screen, in terms of all those different sensors
used together, you just load up your GPS, get the coordinates
off of the screen, and basically walk up to whatever part of
the site you want to start excavating. Obviously this saves
a lot of time and effort, and really focuses where one has to
invest to do the research.
NTB: What are some new research methods that
resulted from the excavations?
Dr. Giardino: We were really impressed by
two things: We started this process by translating the diary
entries into geographical locations. We were amazed at how accurate
the surveyors were at the time using such crude instrumentation.
The same revelation occurred to us when we started to get these
early British and French documents and registering them to our
map. The first insight was that these surveyors were no slouches.
The second approach was that we were able to do a lot of non-intrusive
work with these instruments. We partnered with the University
of Mississippi to bring on other geophysical prospecting tools.
One of the things that immediately became evident was that we
were able to cover large areas of ground and then take the results
and put them in a 3D virtual rendering environment. This allowed
us to perform analysis in an immersive environment where, in
fact, you could peal off the radar signals layer by layer and
immerse yourself in a “test pit” and be able to
look in all four cardinal directions and see what the radar
had seen. You could overlay that information with the actual
excavation and you can match signals with the real strata in
the excavation. This not only helps with the analysis and the
research, but also from the outreach and education point of
view where you can load these virtual renderings on to a geo-wall
or in a large theater setting and allow the public to experience
both the archeology and the recreation of the town, which we
have been able to do from old photographs and the like. This
way a person, without coming on site, can virtually tour the
old town of Gainesville and pick any period they might want
to tour – early prehistoric, French, or most recent historic
period (1850’s and 60’s).
NTB: Could these methods be used in other
fields?
Dr. Giardino: I’ll start from the simplest
to the most complex uses of the technologies in other applications:
the ground-penetrating radar is used in civil engineering to
look for voids under highways or to identify buried pipe or
those types of things. The next step up would be to use it in
conjunction with a GPS so that data can be dumped right into
a program, such as a geographical information system (GIS),
or anything that allows for the development of maps with accurate
coordinates.
The employment of NASA satellite technology, especially remote
sensing technology, while not used as frequently is beginning
to be used for instance you have thermal channels that could
determine underground leaks or anything that has a temperature
gradient, such as very cold or very hot liquids. Because of
the way the signal from the satellite often matches the one
from the ground-penetrating radar, once they are understood
either one could be used instead of the other which means that
any commercial institution that wanted to do that type of work
does not have to buy both.
The most advanced effort going on now is the visualization or
rendering of the signals and data in a way that is understood
by the public. For example, an electric company that wants to
find underground pipes or conduits would run simulations virtually
and immerse their technicians in that environment to allow them
to switch components and parts, run currents through, see what
the impact is, and therefore save a lot of time and effort,
rather than digging first.
With the environment that we’re in here in Mississippi
after hurricane Katrina, there are a lot of applications for
just finding buried gas pipes because the features on the surface
are pretty much gone. The combination of the methods that we
are using could be applicable to their recovery and rebuilding
efforts.
NTB: What is the future of this program?
Dr. Giardino: The Gainesville site is set
aside and preserved, and sometimes we run teacher workshops
down there when they’re interested in history and archeology.
The methodology has been exploited by other NASA centers because
one of the things that we do is combine all of the data that
we talked about and then develop GIS predictive models for the
entire site. For example, knowing the parameters that define
the location of known sites, you enter those parameters for
the rest of the area and then define high- and low-probability
areas for additional sites. Other centers, like Kennedy and
Marshall, that have large land holdings can benefit from this.
We also have expanded from the historic village to the 30+ NASA
historic landmarks that include our test stands, the Apollo
I test stand, and wind tunnels and such. We are now purchasing
some very accurate laser equipment the render the buildings
as they are today and manipulating them virtually to recreate
the environment of when they were historically significant.
The Apollo I test stand at Kennedy, for instance, is basically
just a metal frame now, but in this virtual environment you
can recreate it accurately to what it was when it was active.
All of NASA’s holdings that have historic relevance are
or will soon be experimenting with this approach.
For more information, please contact Dr. Marco Giardino at marco.j.giardino@nasa.gov.
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