Mapping Ancient Egyptian Sites With GPS and Imagery

Hundreds of viper trails covered the sand before them. The Egyptologists could only hope that the serpents themselves were long gone as they made their way off the ancient desert road towards the limestone cliffs.

First to reach the wall, Dr John Coleman Darnell of Yale University, was surprised to find the surface covered with rough hieroglyphic inscriptions in apparently random patterns. What did they mean?

His past experience in the field led Darnell to think the markings were graffiti. The wall was close enough to an ancient campsite to serve as the common latrine for drivers, merchants and guards. The inscriptions, over 500 counted so far, were the ancient equivalent of writing on the bathroom wall. Darnell was the first person to see that graffiti in possibly 5000 years.

Using standard archaeological methods to measure, record and interpret the inscriptions on this wall could be the work of an entire career, by itself. But Professor Darnell’s plan wasn’t to use conventional techniques in this survey. His team was packing a technological edge that would make quick work of this fascinating new find.

When most people think of Egypt, the Great Pyramids, the Sphinx, Queen Cleopatra, King Ramses II and, of course, the boy king Tutankhamen, spring to mind. In the popular imagination, thanks to explorers like John Carter and classic films such as The Ten Commandments and Cleopatra, Egypt is renowned as an ancient land of mystery whose roots run back to the foundations of human civilisation. It is the Egyptologists who dedicate themselves to uncovering the hidden past of this glorious land.

An author of several books on Egyptology, including Tutankhamun’s Armies, with Colleen Manassa (J. Wiley and Sons, 2007), Professor Darnell is the co-director of the joint Thebian Desert Road Survey and Yale Toshka Desert Survey.

Darnell’s team is working in a harsh environment in the Western Desert, which lies to the west of the Nile in Egypt, Libya and north western Sudan. About 700,000 square km in area, the temperature can rise to over 40 degrees in the midday heat and drop towards zero at night.

The varied terrain includes shifting sand dunes in the Great Sand Sea that can reach hundreds of metres high, and vast, featureless plains of rock and stony plateaux, some reaching 2000 metres.

Although easy to lose yourself in the vastness of the Western Desert, modern satellite imaging and mobile GPS locators mean it is very unlikely to stray completely off ‘mapped’ terrain. However, Professor Darnell says the archaeological map for the region is still quite bare.

Archaeologists are the most meticulous and versatile of explorers, covering vast distances in a few days or mere inches in a month. Their discoveries can vary from massive temples or burial sites to shards of pottery scattered across an endless desert plain. With enough patience, they might be able to construct a complete urn.

A good archaeologist has lots of patience. Although often backbreaking work on hands and knees with shovels and trowels, or lying on the ground for hours searching for tiny shards of pottery amidst pebbles, bits of bone and offal cast away millennia ago, it can provide a goldmine of information about a past world.

The measuring and recording of sites is one the most tedious jobs for an Egyptologist. Typical methods take an inordinate amount of time and meticulous record keeping, both on-site and in the office. Intensive surveys, for example, involve teams of archaeologists walking slowly side-by-side across a site marking each find with a small flag. Each one is then individually recorded and described in detail. The records are then sent off for later review and interpretation.

The on-site work is only part of the vast machine that records, analyses, and archives thousands of observations, measurements and locations. A massive web of record keeping work surrounds each field expedition and binds them together with the larger archaeological record. Without this detailed work, pieces of the puzzle could be misplaced or misinterpreted resulting in whole sites lost in the vastness of the desert.

A few archaeological expeditions have turned up finds that cannot be placed in the historical record because of unclear record keeping. On the other hand, searching through even the most meticulous of records can be a daunting project.

One such example is the legendary City of Troy records of the Heinrich Schliemann, Wilhelm Dörpfeld, and Carl Blegen expeditions, where new date is still being found since its discovery over 70 years ago.

Archaeologists have to think in three dimensions, which make things more difficult. Generally, the deeper into the ground you go, the further back in history you are seeing. For centuries that work has been accomplished with the same basic technologies: rulers, plum-bobs, photographs and maps.

Lost sites have been rediscovered years later, most recently the King Menkauhor pyramid, relocated after 166 years (German archaeologist Karl Richard Lepsius’ reported discovery in 1842 went unconfirmed.)

Darnell was hoping industrial GPS technology could help speed up the process and accuracy of their work.

One logical concern was the learning curve. The professors and their graduate students needed to be able to use the equipment with limited support in the field, as they are the ones who have spent the majority of their lives learning about former cultures and ‘dead’ languages. They’re not professional engineers or surveyors, however their fieldwork does require a specialised understanding of surveying techniques.

In the event, the team went into the field with a Topcon GPT-2005 reflectorless total station. Professors and students underwent training essential to prepare the group for their upcoming expedition.

The team uses the equipment in three ways. First, a lot of time is spent mapping the ancient desert caravan roads that run from Thebaïd to Kharga Oasis. But surveying the road doesn’t only involve drawing lines on the map.

There are ancient campsites and military outposts, some dating back 5000 years, to be identified. That means finding buildings and lots and lots of potshards. Darnell explains: ‘Broken pots were seldom recovered by their original owners, as they were un-reusable. They left them where they fell.’

With the total station, Darnell’s team could place-capture potshards almost instantly. There was no more need for the meticulous record keeping on-site, with GPS technology, a simple point-and-shoot process replaced an immense record keeping apparatus and allowed the Egyptologists to get results very quickly.

They also used the total station to situate the ancient graffiti site – which they named Kom Hefaw, meaning ‘mound of serpents’ – and the specific inscriptions at the sites (over 500 inscriptions so far).

The ability to produce a 3D record, again with a simple point-and-click, saved countless hours of measuring, situating and recording the inscriptions. And they can find their way back to an exact inscription easily.

The total station transformed the archaeologists’ efforts, from laborious manual measurements with tape and plum-bob, allowing for precise measurements in a fraction of the time. They were able to lay in their own specific grid pattern of the site. Even more significantly, the site could be revisited at any later date. This allowed for future expeditions to carry on with the efforts of previous groups.

Darnell has facilitated computerised surveying equipment since 2003. In 2007, he began using a total station – a GPT-7005i – that provides a digital image to correspond with points shot on the ground or a vertical surface, such as a building. It became possible to combine digital imagery and measurement for the first time.

On the ground, the difference was obvious immediately. At Tudenab, the team located an ancient deep well and could produce a 3D digital plan of it practically on-site.

The well was not a complex project, but they had another surprise coming. After assembling their data from the Ghueita Temple site, they were able to generate a 3D model of the temple that could be examined from any angle, whilst sitting in a hotel room in Cairo.

‘We were really surprised,’ said Darnell. ‘We knew it was possible to use the software that way but really never imagined it would be so easy. In the models, you can “walk” right through the building and see the placements of all the major architectural elements. It’s really impressive.’

Using the 3D images – combined with satellite linkages and other technologies – archaeologists from around the world will soon be able to work simultaneously ‘on-site’ from any internet connection.

In the future, Darnell hopes that the GPS technology will continue to help us understand our past and, in so doing, better understand ourselves.(source)