April 5th 2012: Hannah Pethen
In the surveying team (see attached photo of the Surveying Team) our main job is to make sure everything found on the site can be easily located on the geographic information system (GIS) computer program that will allow us to locate things precisely in future. At the end of last week we undertook a traverse to determine the coordinates of three new survey stations that were cemented into position in September 2011. The stations will provide secure fixed reference points for topographic and archaeological survey of the site, and it is therefore important that the coordinates we have for them are as accurate as possible. The traverse allows us to determine the coordinates of the stations with a high degree of accuracy, and although it took two days, it was certainly worth it.
For the last week we have been tidying up the site survey, plotting the locations of various finds and undertaking a topographic survey of the site. We don't generally find particularly exciting things (like kilns) during our daily work, but its great to see the topography of the site slowly appear in our computers. The topographic survey was begun last September, when I covered the area of the Harem Palace itself, the area of the tell to the north east and part of the wadi to the west. I used the survey to create a model of the landscape and the results looked very promising. The aim for this year is to complete as much of the main area of the site and extend it northwards towards the north tombs. I was delighted to find the markers I had left at the end of last year's survey were still in place and I could continue this year's survey from the exact location without looking it up on the GIS. I have also been excited to use a new piece of kit, called a Robotic Total Station. A Total Station is essentially a modern form of computerised theodolite that is also able to measure height and can therefore provide a reading in three dimensions. It fires a laser at a prism on a staff, which must be located on the point which is to be measured. Last year's survey was also undertaken using a Total Station, but it required two people; one to aim and operate the Total Station itself and another to carry the staff with the prism to the points. A Robotic Total Station only requires one person to operate it. The prism is carried by the operator, who also has a remote control for the Total Station, they are therefore able to give the Total Station instructions on when to fire at the prism. The Total Station is capable of automatically following the prism and of searching for it if necessary. This has given several team members a surprise as they walked up to the Total Station only to have it rotate round and look at them as it follows the prism. It is really quite creepy to have a machine apparently working by itself, even if you know that a colleage is controlling it from a distance.
Despite its slightly alarming behaviour, it is a fantastic piece of kit. During the 11 days of last year's season, I was able to take 5829 points, with each point approximately 5m from the last one. So far this year, in the six days I've been surveying for the topographic survey, I've taken 3189 points at the same 5m interval. I'm hoping that now the system is set up, and barring any further sandstorms, I'll be able to get 1000 points surveyed each day for the rest of the season. The attached picture, called 'Gurob survey 2011-12' shows the area covered by last year's survey (in red) and this year's survey (in blue) against a background of the aerial photograph of the site.