西藏壁画空鼓病害的探地雷达检测

以高频脉冲电磁波在层状有耗色散介质中的传播规律为理论依据,在室内模拟试验的基础上,运用RAMAC GPR探地雷达对表面有涂层的西藏壁画进行壁面耦合式空鼓病害检测。实验表明,超宽带探地雷达方法适用于检测壁画内部的空鼓病害,配备中心频率1.6 GHz天线时的垂直分辨率约为5 mm。在壁画空鼓病害的定量检测方面做了有益的尝试,促进了我国壁画保护技术水平的提高。

Detection of Delamination in Tibetan Wall Paintings by Using Ground Penetrating Radar

In tradition, the diagnosis of delamination in either grotto wall paintings or palace wall paintings is achieved by identifying the sound when lightly knocking on the wall by hand, such experience is practical in determining the area and degree of delamination, but it depends on subjective sensation, lacking some theoretical principles. Focusing on the propagation of high frequency pulse electromagnetic waves in layered lossy and dispersive medium and after the physical forward modeling experiment, this paper tries to locate delamination in polished wall paintings in Tibet by wall coupling antennas using RAMAC ground penetrating radar. It is shown that the ultra-wide band ground penetrating radar is capable of detecting delamination in vertical resolution of about 5 mm when it is equipped with a transmitting antenna of 1.6 GHz central frequency. It is a quantitative attempt to detect delamination in wall paintings, the research results promote technical improvement for conservation of wall paintings.