透地雷達(Ground Penetrating Radar,GPR)是一種具更高解析度的非破壞探測技術;其為一種地球物理探測方法。GPR因對不同地層界面間介電常數不同,造成GPR產生的電磁波在地層中的穿透與反射會有所不同,並藉此判斷GPR掃描下地下的情形。本研究利用400MHz透地雷達天線頻率配合 Curvelet Transform對透地雷達影像雜訊進行抑制,藉由測試地區的柔性鋪面下陷維護路段進行現地試驗、影像蒐集,最後判別路面下陷部位與施測時天線拖曳時,造成的雜訊是否可被有效地抑制。並經由實驗結果,我們可以知道Curvelet Transform在雜訊抑制上的效能比起Wavelet Transform更為有效。
Ground penetrating radar (GPR) is a nondestructive probing method with high-resolution. The principle of this geophysical probing technique uses the penetration and reflection characteristics of electromagnetic waves while the waves were propagating through ground layers. Therefore, the nondestructive GPR probing technique may solve problems in a quicker way, and improve survey quality. When the GPR electromagnetic waves struck different ground layer boundaries, the specific dielectric constant of each layer causes the reflective wave differ from the original incident wave,and it can be used to determine the circumstances under GPR scans the ground. In this study, we applied the GPR technique for the problem of flexible pavement subsidence at a section in the test area.The investigation used a 400 MHz transducer, an then, the captured GPR images were depressed the noise effects by introducing Curvelet Transform de-noising algorithm. The signal-noise-ratio was used to determine the effectiveness of noise reduction. With the experimental results, we can know Curvelet Transform performance on noise reduction is more effective than the Wavelet Transform does.