Combination of bathymetric and terrestrial survey in one system

Two technologies, Multibeam Echosounder Systems (MBES) and Laser Bathymetry and Topography Systems (LBTS), will meet the majority of tomorrow's survey needs in the coastal zone. Both systems provide full bottom coverage. The area coverage for a MBES is direct proportional to the water depth while the area coverage for the LBTS is independent of depth. LBTS have been used in shallow waters down to a maximum depth of around 70 metres, and are showing a capability to meet IHO Order 1 standards to depths beyond 30 metres. The depth capability of laser systems depends heavily on the water quality. Turbid, or unclear, water will reduce penetration. In the areas where LBTS can be used it has the following advantages: cost efficiency. The cost compared to MBES surveys can be of the order of one tenth or less for very shallow waters (0-20 metres); topographic survey of coastlines. Both water depth and topography can be surveyed in the same mission in the same geodetic framework; rapid transit and completion; better safety for crew and equipment in unknown or hazardous waters; and detection of the waterline. The economic and operational advantages of integrating survey systems such as MBES and LBTS in a hydrographic programme for coastal waters offer Hydrographic Offices and Agencies a better solution than reliance solely on ship borne surveys. Combining a below and above water survey capability in the same mission goes further towards meeting the many different needs of customers in the coastal zone than traditional, separated, land and sea surveying does.