Determination of Grave Locations in Dedemezari Necropolis (Western Turkey) using Magnetic Field Derivatives A. BÛYÛKSARAC ¸ 1 * , M. O « . ARISOY 2 ,O « . BEKTAS ¸ 2 ,O « . KOC ¸AK 3 AND T. C ¸AY 4 1 Cumhuriyet University, Department of Geophysical Engineering,TR- 58140, Sivas,Turkey 2 Ankara University, Department of Geophysical Engineering, BesevlerTR- 06100, Ankara, Turkey 3 Selcuk University Faculty of Science and Letters, Department of History, Konya,Turkey 4 Selcuk University Faculty of Engineering and Architecture, Department of Geodesy and Photogrammetry, Konya,Turkey ABSTRACT The location ofthe studyarea for this research ofa Middle Bronze Age Necropolisis situatedin the west of Turkey near Afyonkarahisar. Magnetic surveying was carried out in two adjacent areas (Areas 4 and 5).Four trencheshave been excavated so farand graveswerelocatedin positionsinterpreted from a magnetic survey carried out in 2005. Initial excavations have shown that cist, pithos and simple graves were placed randomly and it is suggested that Dedemezari Necropolis is similar to the well known necropoleis of Gordion and Sariket. This paper compares the results of some phase-based filters which show improved performance as edge detectors in different ways.The filters are demon- strated on synthetic magnetic data and magnetic field data from Dedemezari Necropolis. Magnetic field derivatives, both vertical and horizontal, are common and useful tools for interpretation of the magnetic anomalies. Interpretation of magnetic field derivatives, separately or together, provide images of shallow bodies from magnetic data. The horizontal derivatives of the total magnetic field were computed in the space domain by means of finite-difference relationships, and the vertical derivative was computed in the frequency domain by using fast Fourier transform filtering. Derivatives of the magnetic anomalies have been used for detection of causative bodies. The analytic signal (AS), the enhanced horizontal derivative (EHD), tilt derivative (TD), theta map, hyperbolic tilt angle (HTA) and total horizontal derivative (THDR) methods were applied not only to synthetic anomalies but also to the measured magnetic anomalies of Areas 4 and 5. However, AS and EHD produced the best results as the other methods created edge effects.Copyright # 2008 JohnWiley & Sons,Ltd. Key words: Magneticanomalies; Dedemezari Necropolis; magneticfieldderivatives; pithosgrave; Middle Bronze Age; Turkey Introduction Geophysical methods effectively detect the locations of buried objects and features on archaeological sites. Some classic archaeological exploration methods such as trenching and drilling require an enormous expenditure of human energy and engender high costs. More- over, these classic methods are destructive for the archaeological sites. Developments in image processing and graphic representation of geo- physical data provide high-speed, non-destructive reconnaissance surveys for ancient human cultural Archaeological Prospection Archaeol. Prospect. 15, 267–283 (2008) Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/arp.338 * Correspondence to: A. Bu ¨ yu ¨ ksarac ¸, Cumhuriyet University, Department of Geophysical Engineering, TR-58140, Sivas, Turkey. E-mail: absarac@cumhuriyet.edu.tr Copyright # 2008 John Wiley & Sons, Ltd. Received 4 September 2008 Accepted 5 September 2008