Edge Detection of Archaeomagnetic Data: a Study from the City of Pisidia Antiocheia, Turkey

摘要

Magnetic survey is one of a number of methods used in archaeological geophysics for detecting and mapping archaeological artefacts and features. Recent magnetic instruments have become both faster and more sensitive as a result of technological and industrial developments. Hence, magnetic methods are becoming an accepted part of archaeological projects. Mapping the edges of magnetic sources is a problem of fundamental importance in magnetic interpretation. Commonly used edge-detection filters are considerably affected by the presence of noise because this requires the computation of horizontal and vertical derivatives of the magnetic data. Archaeomagnetic data are often dominated by large-amplitude anomalies thatmostly originate from the presence of noise and other environmental effects. Prior to application of the edge-detection filters, an upward continuation of the archaeomagnetic anomaly or low-pass filtering may be used to reduce environmental effects. Another useful approach is to apply edge-detection filters to the pseudogravity-transformed data. This paper compares the results of common edge-detection filters applied to the original and pseudogravity-transformed archaeomagnetic data. In the concept of edge detection, the feasibility and capability of the pseudogravity transformation is demonstrated using a real archaeomagnetic dataset from the ancient city of Pisidia Antiocheia in the province of Isparta (central part of Turkey).