Extraction of signal signatures from ground penetrating radar data for archaeological investigation

Abstract

Archaeology is a study of ancient material remains and human activities through previously era. Various methods have been used in archaeological data detection purposes, such as magnetic, electromagnetic and earth resistance techniques. The basis of these techniques based on its ability as prospecting tool to determine position, generate images and underground mapping. Currently, the Ground Penetrating Radar (GPR) method has been applied in archaeological prospection to reveal the near surface composition of artefacts. However, the lacking of the analysis of GPR radagram and the used of conventional method which is time consuming and laborious for findings archaeology vestiges are still been applied. This research was conducted to evaluate the capability and effectiveness of GPR in archaeological prospection. The first objective of the study is to identify the signal properties of electromagnetic wave penetrations which are the velocity and dielectric permittivity on different subsurface sediment and object buried. The second objective is to analyse the power of reflectivity of archaeological vestiges at sites and the final objective is to generate three dimensional (3D) time-slices data of archaeological area. To achieve the aims of the study, data acquisition at three different test sites involving of simulation test bed at Universiti Teknologi Malaysia and two real sites at Sungai Batu, Merbok, Kedah and Pudu Jail, Kuala Lumpur with different artefacts have been performed using GPR. The real sites selected in this study were suggested by the archaeologist from the Department of National Heritage, Malaysia. For all sites, grid lines were established to aid in GPR scanning and this method is the best applied in the generation of 3D models of the scanned images. Accordingly, each transversal and longitudinal line was scanned with the aim of deriving the signal signatures to discover the existence of artefacts and the electromagnetic properties of the sediment and artefacts. Besides, 3D model and time-slices are generated for better interpretation of the results. Based on the fitted velocity results obtained, it were successfully derived the dielectric permittivity of the sediment of the three test sites with a value of 14.793-25.000, 4.000-6.250, and 4.000-18.367 respectively. The observed values are comparable to the published values provided in previous study. In addition, the dielectric permittivities of artefacts were derived with a value of 9.000-14.060, 5.325-18.367, and 7.438-11.111 respectively. Moreover, the 3D models and time slices of the GPR data radagram were generated to enhance the radargram analysis. As conclusion, the results from this study can facilitate archaeologists to identify buried archaeological artefacts for planning stage of archaeological prospection in Malaysia which largely contributes to the Department of National Heritage and to the knowledge for rest of the world.