Geophysical exploration of Location and course of the Herodian city wall under the present-day Christian quarter of the Old City of Jerusalem: Confirmation of a new hypothesis

• Applicants: Dr.-Ing. Jürgen Sachs; Professor Dr. Dieter Vieweger
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Egyptology and Ancient Near Eastern Studies
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 267888325

The archaeological goal of the project is to close a 150 year period of unsuccessful search of the city wall of Jerusalem from the time of Herod the Great by confirming its existence and thus to permit the reconstruct of its correct location and arrangement. The many times controversial discussed course of the building – referred to as the "Second Wall" by the Jewish historian Josephus Flavius – is of paramount importance for the historical topography of Jerusalem from the Herodian period until the destruction of the city in August 70 AD. The question of the Herodian city expansion also has a serious impact on the reconstruction of the Jewish and Christian topography of Jerusalem (Herodian city and descriptions of Flavius Josephus), especially on the localization of the Via Dolorosa described in the New Testament and the crucifixion place Golgotha.In face of the extremely strong exploration restrictions in Jerusalem due to disputed ownership, complete urbanization and UNESCO constraints, the intensely over decades discussed key question on Urban Development of Jerusalem has to be solved by geophysical prospection via Ground Penetrating Radar (GPR). For this purpose, sounding waves in the frequency band of 30 ... 200 MHz are used to ensure good penetration into the soil while simultaneously achieving good distance resolution. Therefore a new GPR concept has to be implemented in order to meet the limitations through the urban measurement environment (antenna size, interference with radio communication).The special challenge of the task is the unusual measuring conditions and the complex propagation conditions of the electromagnetic sounding waves. These result both from the housing density and the spatial limitations of the test area. An original assumption was based on the fact that the wall was located near an excavation site below the Church of the Redeemer. This assumption has not yet been confirmed. On the other hand, the already performed GPR measurements in the urban area of Jerusalem have given new indications for a slightly modified wall course. This must be confirmed by further measurements. For this purpose, the exploration area is expanded correspondingly so that now also alleys with a stairs-like structure have to be included in the investigations. The narrowness of the streets, their stepped course and the sewage system are major challenges for a GPR measurement. This is to be taken into account with a novel device concept and various scanning methods. The principle of the GPR-device is primarily based on a combination of ultra-wideband pseudo-noise technology with the concept of "Large Current Radiator". It enables an efficient feeding of the transmitting antenna which is of very compact size.

• DFG Programme: Research Grants