Derivative based algorithms and their applications for archaeomagnetic data

The application of geophysical methods to archaeological sites has made it easier to locate and protect the buried remains. Archaeological studies conducted with the help of archaeogeophysical methods prevent unintentional damages to the remains and provide to determine the location, depth and status of the archaeological remains. In addition, it provides great advantages in terms of planning and guiding the archaeological excavations. One of the most frequently applied geophysical methods in archaeological sites is the magnetic method. Due to its mathematical nature, boundary/edge determination techniques play an important role in the application of magnetic method which includes many data processing techniques. In this study, magnetic data collected by gradient measurements in Amorium ancient city in Emirdağ district of Afyon were used. Directional derivative based techniques were applied to magnetic data to determine possible structure boundaries. In addition, these techniques were applied to the data produced with the help of theoretical models before the real data applications. The advantages of edge determination techniques such as vertical derivative, second vertical derivative, total horizontal derivative, analytical signal, profile curvature, tilt angle, theta angle and normalized standard deviation were investigated. In the applications, firstly magnetic data were transformed to pseudogravity data and then directional derivative based operators were applied. In the theoretical study, it was observed that the boundaries of the model structures were determined more successfully in total horizontal derivative, profile curvature, theta angle and normalized standard deviation anomaly maps, while the most successful results were obtained through the total horizontal derivative operator in the real data applications. It is thought that the high amplitude traces observed in the resultant anomaly maps may be the remains of archaeological structures and archaeological excavations are recommended in these areas.