Measurements of the low-frequency underwater channel features in a littoral environment using a plasma sound source

In the shallow water environment,the propagation features of the acoustic channel and its variability are important for many littorial applications,such as long-range underwater target detection and communication.In order to measure the low frequency(LF) channel characteristics,a towed plasma sound source(PSS) and a vetical received array were used in our shallow water acoustic experiment,performed in Sept.7,2008.Through the comparision of the measured data with the wideband channel simulation model outputs,based on the KRAKEN Program,we analysised the PSS and channel features,including the source's waveforms,directivities,energe transform efficiency and the channel multipath structure.Experiment results show that the numerial analysis is well comformed of the measurements and the used PSS system is suitable for the continuously mobile underwater channel measurements task,due to its good stability of sourse level,towed posture and consistency of pulse waveforms.