| 講演要旨(和文) | | 著者らはRTK-GNSSとHS350と搭載したGPRシステムを用いて遺跡調査を始めた。我々は岩原双子塚古墳群の古墳をGPR探査を実施した。円墳内部には、遺体が埋葬された石棺が埋設されていると考えられており、GPRはそれを取り囲むように測定している。解析では、地形面で変わる電波の放射方向を計算し、頂上部を中心に放射状に360°配置した測線のデータを用いて3次元のディフラクションスタッキングを行った。解析の結果、墳丘の頂上部より深さ1.2〜1.7m付近に顕著な反射体が分布していることがわかった。この反射体周辺のみを対象に、水平方向のグリッドサイズを4cm、深度方向のグリッドサイズを5cmとして、詳細なイメージングを行った。反射体の形状を考察した結果、石棺の形状が複雑になっていることから、盗掘された跡である可能性を推定した。 |
|
|
| | 講演要旨(英文) | | The authors have started GPR survey for archaeology using GPR system combined with RTK-GNSS and HS350. The RTK-GNSS enables us to determine the horizontal position of the GPR antenna within 1cm and the vertical position within 1.5cm in real time. HS350 is the GPR antenna, made by GSSI in the US, adopted real-time sampling, and signal to noise ratio of the antenna is being improved by stacking the GPR waveform with several hundred times. Since both devices synchronize, we can achieve dense survey effectively. We conducted the GPR survey at Umamukazu burial mound where was located at the crowd of Iwabaru ancient burial mounds in Yamaga City, Kumamoto Pref. We measured 190 radial lines from the top to the bottom of the round burial mound with line-interval of 1.9 degrees. It was considered that a stone coffin which a dead body of regional powerful clan was placed was buried inside the round burial mound. And the survey lines of the GPR were arranged as surrounding the stone coffin from subsurface of the round burial mound. We calculated the emitted direction of radio waves if the surface of the round burial mound changed, and applied diffraction stacking method in three dimensional grids model using radially survey lines of 360 degrees. The results of the GPR imaging showed that remarkable reflections appeared in the depth range of 1.2m to 1.7m beneath the top of the round burial mound. Furthermore, we re-calculated focusing on the remarkable reflectors area with the 2cm grid size. Since the shapes of the remarkable reflectors considered as a stone coffin were complicated, we estimated that it might be traces after robbers excavated. |
|
|
|
| |
|