Effective 3D GPR survey and its application to the exploration of old remains

Since the buried cultural relics are three-dimensional (3D) objects in nature, 3D survey is more preferable in archeological exploration. 3D ground penetrating radar (GPR) survey based on very dense data in principle, however, might need much higher cost and longer time of exploration than other geophysical methods. We developed a small-scale continuous data acquisition system which consists of two sets of GPR antennas and the precise positioning device tracking the moving-path of GPR antenna automatically and continuously. Besides this hardware system, we adopted a concept of data acquisition at arbitrary locations not along the pre-established profile lines, since the high cost of field work may be partly attributed to establishing many profile lines. Using the developed system, we performed 3D GPR survey to investigate the possible historical remains of Baekje Kingdom at Buyeo city, South Korea, prior to the excavation. Owing to the newly devised system, we could obtain 3D GPR data of this survey area having a real extent over about 17,000 m² within only six-hours field work. Although the GPR data were obtained at random locations not along the pre-established profile lines, we could obtain high-resolution 3D images showing many distinctive anomalies, which could be interpreted as old agricultural lands, waterways, and artificial structures or remains. This case history led us to the conclusion that 3D GPR method is very useful not only to examine a small anomalous area but also to investigate the wider region of the archeological interests.