Advanced Digital Processing of Echo Sounder Signals for Characterization of Very Dense Submersed Aquatic Vegetation

摘要

Characterizing submersed aquatic vegetation (SAV) is important for a variety of purposes including ecological assessments, impact analyses of human activities, and planning control operations to manage nuisance aquatic plants. Until recently, the standard techniques for characterizing SAV distribution and conditions were by manual means (grab and rake samples, and diver observation and collection) and remote optical techniques (aerial photography and digital satellite image analysis). Manual techniques provided detailed and accurate information, but only for very limited areas. Remote optical techniques provide a large-area synoptic view of SAV distribution but only in limited detail. These techniques are limited by water clarity, commonly underestimating extent of SAV in deeper waters. Recently, an automated digital technique was developed that employs a digital echo sounder, global positioning system, and digital signal processing on a PC in near real time. This technique fills the void in methodology by rapidly providing high-resolution information on SAV canopy geometry from a small survey boat.