Edge detection for the buried archaeological structures with the geophysical image processing method in the Alabanda Ancient Cistern in Turkey

Abstract

Edge detection techniques are some of the most useful techniques to determine the lineaments of buried structures from magnetic data. In this context, many techniques have been designed by using the magnetic gradient tensor (MGT). In this work, eigenvalue analysis of the full MGT and a new normalized approach [normalized edge detector (NK)], which balances strong and weak amplitude anomalies simultaneously, was utilized to outline lineaments of the buried archaeological structures. Satisfactory results were obtained from noisy and noise free synthetic data which were generated from prism models. The techniques were implemented on the archaeological magnetic data acquired from a buried ancient cistern. In addition, three-dimensional (3D) electrical resistivity tomography (ERT) inversion sections and two-dimensional (2D) magnetic inversion section and tilt angle methods were used to compare them against the results of edge detection analysis. The results of the normalized eigenvalue analysis agreed closely with all techniques in detecting the lineaments of the buried archaeological structure. NK detected the lineaments of the buried structure more clearly than the tilt angle and had better resolution. All of the results have shown that eigenvalue analysis of the full MGT and especially the newly introduced approach NK can provide important information for archaeological studies.