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Well, my original aim with the Pavlopetri Project was to record it in as much detail
as possible. It was first surveyed back in 1968 by a team from the University of Cambridge
using measuring tapes and just snorkels on the surface, and they did a fantastic job.
But the reason we've gone back 40 years later was to use new technology, and to use the
cutting edge of technology of the year and it's developing so quickly that each year
almost we've used different techniques.
Probably now Pavlopetri is the most surveyed bit of sea bed in the world and we've applied
probably more techniques to it than, you know, than anywhere else, and every year I think
this is the best survey technique, no actually this is the best survey, oh no now we've cracked
it.
But now actually I honestly believe that we have a technique which is going to, I think
revolutionise the way people do underwater survey. It doesn't just work in shallow water,
it works in very deep water as well and what it gives you is a photo realistic impression
of the seabed. I mean just as the seabed looks. I mean when I started the project I couldn't
have hoped for the technique that we've now got.
Essentially it's a technique that's been developed by the Australian Centre for field robotics
and it's a stereo photogrammetry technique and what that means is it's a, it's a system
that uses stereo photo cameras over the site to create a map, a photo map of the site,
but not only that it adds 3D into it for the two different perspectives from the cameras.
Equally they can attach a multi-beam system to this equipment which is like an acoustic
system, which will give you a 3 dimensional impression of the seabed. So, basically you
mesh the photographs together with the, the 3D mesh and you've got a 3D photo realistic
surface. You can go down and you can, you can examine individual shards in the seabed
and the resolution is such that you can actually identify them and then you can pull out to
then look at the full sight in over eight hectors.
So really it's, it's for me it's just phenomenal. And the nice thing about the Pavlopetri Project
is we've used lots and lots of different techniques so we have lots of comparisons to assess how
accurate a particular technique is and the base level that we used was simply using a
total station. That's a laser method, it's a machine that shoots a laser out to a prism
out in the water and it's exactly the sort of thing you'll see people surveying motorways
with, or you know doing building surveys with, you'll see them, you know in every city in
the UK.
We use that in the water using just a slightly longer pole and divers out in the water but
that's given us a baseline, a very accurate baseline, to within about five centimetres
as a level of error, for the whole plan and that's given us a plan of the city but it's
vector lines. It's just lines like you know you would draw, with a big, if you imagine
a big digital pen. It's a two dimensional plan but it's also got the 3D information,
so you can look at it in 3D, but it's just lines.
And what this new technique has given us is the actual photo realism which we can overlay
onto that and check the accuracy of it because we've also used other techniques. We've used
acoustic techniques which work a wee bit like laser scanners and you get point clouds. So
you get 3 dimensional point clouds underwater.
We used a technique called Sector Scan Survey developed by a company called Kongsberg Mesotech
and it was a group from America, a nautilus marine group who came and did that for us
last year. And that was fantastic and very, very quickly you can get a 3D point cloud
of what's under water. So you can find things, you can get two-dimensional maps from it very,
very quickly, but the reason the new technique is so good is because it's photo realistic.
People can look at it straight away and go 'Oh wow that's a, you know that's a submerged
city!' you know.
What's been exciting about working with the BBC and bringing them on board, is this year
we managed to work alongside CGI movie professionals. These are people who normally work on films
like Star Wars. Prime Focus they're called and they are actually working on Star Wars
Episode One, making it into 3D at the moment.
Anyway, so we were actually able to work alongside these people in the field. I mean normally
what would happen when there's a reconstruction, is the archaeologists will go and do the work,
and then the TV people will make the reconstruction. There would be no connection between the two,
but what we were able to do because we were getting this 3D photo realism in the field
was actually, at the same time, have the guys from the CGI company build the walls and work
with the archaeologists.
So for I think, for amongst probably the first time we have a, we have a, a data-driven reconstruction.
It's based on the archaeology and it's produced by a team that worked with the archaeologists.
Well essentially what we're doing is bringing a 3000 year old city back to life. You know
something that hasn't existed for 3000 years and that's the exciting part of it. It makes
you change your view of the city, in a way that you wouldn't have done just working on
it. Because we had these guys working with us and I was looking at walls and I was thinking,
well this this room could be something different this is, this is a house, but this is a building
of a slightly different function and when you start building the walls and start looking
at it in a way that you don't see it underwater you can come away, above it, you can look
at it you know you can really examine it.
I began to kind of change my interpretation of certain buildings and you know the, the
CGI team became part of the research process and there was quite an exciting synergy between
the CGI guys and the archaeologists in the field.
Well this is the third year of what we hope is going to be a five year project and we're
in the process now of applying for the next permits to start excavations on the site.
This year we carried out a couple of quite small test trenches, just to see if there's
deposits surviving on the site.
Thankfully what we found was there's actually still quite a lot of deposit to be excavated.
For example, we're finding the top of storage vessels, the top of pithos storage vessels,
which we think were imported from Crete interestingly enough, but showing networks of contact throughout
the eastern Mediterranean. But the top sitting in the, in the seabed implies there's a meter
to a meter and a half of deposit still to be excavated underwater.
So I think the next phase is when it gets really exciting, that's when we start to really
start finding the material, and hopefully because the site is a submerged site, because
it's underwater, we should be getting organic items, wooden items. The kind of things that
don't survive on land because it's a, you know because underwater is a site, it's an
area that lacks oxygen, and particularly when things are covered up with sand you get a
nice oxygen-free environment: organic food remains can survive, you know rope could survive,
baskets could survive from the Bronze Age which would be a really thrilling find.
We'll use the stereo photogrammetry to record the trenches in three dimensions as we're
excavating them, and we trialled this, this year as well. The idea that you, you excavate
a level, a layer, and then you do the stereo photogrammetry technique in 3D. Then you excavate
the next layer, you do it again and then the next layer and the idea is that you can go
back and almost re-excavate the site.
And we're recording exactly what we're doing in three dimensions as we go through the deposits.
So we're creating a record that other people can then go back and use, and can go back
and analyse, and perhaps even re-interpret.