Between July 26 and August 3, 2002, research was conducted by Prof. William Aylward of the UW-Madison Classics Department, Dr. Jim Compton Tucker of the NASA Goddard Space Flight Research Center, and Jamon Van Den Hoek in partnership with the Troia Project by using a magnetometer linked with a global positioning system receiver (GPS) in the Troad of northwestern Turkey. The purpose was to locate and map the underground pipeline and conduit of the 1st c. A.D. Roman aqueduct that led into Ilion (Roman-era Troy). Though magnetometry was used in the research, other techniques could have been implemented in concert with or in replacement of magnetometric methods. The use of magnetic surveying in the summer of 2002 in the Troad is just one of many recent instances of applying subsurface remote sensing techniques and technologies in an archaeological context.
[...] In a setting such as northwestern Turkey in the fields surrounding Ilion where the ground is so dry that large, deep cracks result from the lack of water, the fact that dry soil enhances a signal rather than retards it would be very advantageous. GPR is also a more rapid approach to subsurface prospection than electrical resistivity methods. GPR equipment is most often hand-towed or pulled by a vehicle over the area to be surveyed at rates up to ten kilometers per hour (Conyers et al. [...]
[...] There, readings with the magnetometer were taken in agricultural fields, on top of a bituminous road, and in a playground with a concrete surface (Figure 6). July 27. Recorded GPS coordinates in preliminary survey of known portions of aqueduct pipes near the series of bridges in the Kemer River valley. Ground survey revealed large terracotta pipe fragments on both sides of the valley. July 29. Took magnetometric readings and GPS coordinates just east of Ilion in several agricultural fields (Figure 7). [...]
[...] As mentioned earlier, there was often a substantial amount of pipe fragments resting on top of the soil in the same areas that we had hoped to find buried sections of the aqueduct. The presence of terracotta on the surface presented a source of error in our measurements as the very material we were attempting to find underground was also aboveground in pieces up to 0.40 meters in length. Therefore the signature we were trying to find was often recorded whether or not the aqueduct was buried at that location. [...]
[...] However other fields such as Hydrogeology, Physics, and Civil Engineering (all of which were incorporated by the Troia Project during 2002) can play prominent roles in a project's findings. Remote sensing at Troia has been utilized since the first season of excavation of the modern campaign in 1988. The application of remote sensing has been used to such a wide extent that Manfred Korfmann, the current director of excavations at Troia, has stated that approximately 330,000 square meters of land in the Troad featuring settlement patterns have been researched through remote sensing without excavation (Ebert, 17). [...]
[...] The data gathered from last summer's research has been overlaid on top of the IKONOS geo-coded images provided by NASA resulting in a detailed view of all of the traverses made with the magnetometer and GPS (Figures 11). From this, an original and accurate graphic representation of portions of the path of Ilion's aqueduct can be extrapolated using IDL software. Magnetometry The magnetometer used in the research was a fluxgate magnetometer. Though fluxgate magnetometers have been used at Ilion before, they are not used in archaeological exploration as much as proton magnetometers which are perhaps used more than all other devices combined. [...]
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