測深光達原理、現有系統與服務

The Principles of the Bathymetric Lidar and the Current Systems and Services

史天元(Tian-Yuan Shih) ； 薛憲文(Shiahn-Wern Shyue) ； 王慧蓉(Hui-Jung Wang) ； 陳杰宗(Jie-Chung Chen) ； 陳佳勳(Jia-Hsun Chen)

《地籍測量：中華民國地籍測量學會會刊》 29卷1期 (2010/03) Pp. 44-58

https://doi.org/10.29609/YYWYLL.201003.0004

摘要

地形測量所使用之空載光達系統多使用紅外波段1064nm波長之雷射光，該波段對水體之穿透力低，若經倍頻後所得532nm波長之雷射光，則屬綠光波段，具有透水能力。使用綠光波段構建之光達系統，可用以進行水深與水底地形測量。與聲波測深系統之成果相比較，其成果雖然尚不能達到IHO規範之特級要求，但是由測試案例與國外實測經驗顯示，目前空載測深光達已可達IHO規範之一級要求。雖然精度並非超越聲波測深系統，空載測深光達具有近岸淺水與礁石區作業之方便性，與船測相較，安全度高，而且作業速度亦高。相較於陸域之空載光達，測深光達之產品成熟度尚低。本研究分析現有商業性儀器，就儀器而言有三種系統，加拿大Optech之SHOALS、澳洲Fugro-LADS (Tenix-LADS)之LADS、瑞典Airborne Hydrography AB 之Hawk Eye。而就研究性之系統而言，美國USGS 使用中之EAARL為一具有未來性之作業中系統。就服務之提供而言，除澳洲Fugro-LADS本身亦提供測深服務，實質進行專案承包外，美國Fugro-Pelagos使用Optech之SHOALS系統，歐洲BLOM則使用瑞典Airborne Hydrography AB 之Hawk Eye II，另一家歐洲公司，英國的Pelydryn則亦使用Hawk Eye II系統。本文謹就測深光達原理、現有系統與服務，歸納研究成果。

關鍵字

綠光雷射 ； 沙奇盤深度讀數

並列摘要

The most common wavelength of the laser beam used by airborne topographic lidar s ystems is 1064nm. This wavelength belongs to the infrared portion of the spectrum, which does not penetrate the water well. The 532 nm laser beam generated from the 1064 nm utilizing the double frequency process, has good water penetrating capability. The bathymetric lidar systems utilize the 532 nm laser, which can be used for the bathymetric survey and substrate mapping. Validated with the sonar based bathymetric systems, the bathymetric lidar may not reach the IHO special order, but can fulfill the IHO specification of first order. The airborne lidar is not superior in accuracy than the acoustic based systems. But, the airborne system has many advantages for the operation in the shallow water area. Studying the current systems available commercially, there are three, namely, Optech SHOALS from Canada, Fugro LADS from Australia, Airborne Hydrography AB Hawk Eye from Sweden. In the non-commercial sector, EAARL system operated by USGS of the States is featured with advanced designs. Fugro-LADS is the only company which provides both systems and services. Besides Fugro-LADS, Fugro-Pelagos of the States operates with an Optech SHOALS, and BLOM from Europe and Pelydryn from U.K. operate with Airborne Hydrography AB Hawk Eye II. This paper introduces the bathymetric lidar system, including the principle, the systems, and the services.

並列關鍵字

Green Laser ； Secchi Disc Depth