空載測深光達具備的安全性與高效能的作業方式,使其成為淺海潮間帶三維地形圖資測繪有利的工具。然由於水體與水底材質分屬性質不同的介質體及反射體,為獲得正確的水底地形,須先掌握空載測深光達的正確雷射脈衝往返行經路徑,並從波形分析中分別偵測碰觸水面及水底之時間點,此兩時間觀測量精度攸關水底三維地形測繪品質。理論上,空載測深光達技術能有效執行淺海潮間帶水底三維地形測繪,然現階段對於水面波形幾何以及偵測水面時間點相關研究仍顯薄弱,此部份實亦關聯水底地形測繪品質的不確定性。本研究主要工作在了解雷射脈衝至水面之交互作用,在水面波形方面考量局部變異顯著的毛細波及重力波。除了藉由改變掃描幾何與氣象因素探討對水面回波波形在幾何與能量上之影響以外,亦歸結在特定掃描幾何及氣象因素下較適當的波形時間偵測法。
Airborne LiDAR bathymetry has been proven an ideal technique in both safety and efficiency concerns for 3-D topographic surveying in both shallow water and tidal flat areas. Yet the crucial challenge for acquiring terrain of water bottom is to precisely capture the trajectory of laser pulse when travelling between different medium, air and water. Therefore, the quality of mapping 3-D bottom terrain would depend on how well the waveform analysis on determining the timing hitting water surface and water bottom can be designated. The goal of this research is to comprehend the reaction of laser pulse on water surface, mainly wind- induced capillary-gravity wave facets. In particular, laser scanning geometry and the meteorological factor that shape the waveform geometrically and radiometrically are analyzed and thus the better timing detection method can be advised. In additional to gaining better understanding of laser-to-water interaction, this work may contribute to highlighting the significance of water surface detection which current airborne LiDAR bathymetric systems overlook.