The deployment of underwater networks allows researchers to collect explorative and monitoring data on underwater ecosystems.The acoustic medium has been widely adopted in current research and commercial uses,while th...The deployment of underwater networks allows researchers to collect explorative and monitoring data on underwater ecosystems.The acoustic medium has been widely adopted in current research and commercial uses,while the optical medium remains experimental only.According to our survey onthe properties of acoustic and optical communicationsand preliminary simulation results have shown significant trade-offs between bandwidth,propagation delay,power consumption,and effective communication range.We propose a hybrid solution that combines the use of acoustic and optical communication in order to overcome the bandwidth limitation of the acoustic channel by enabling optical communicationwith the help of acoustic-assisted alignment between optical transmitters and receivers.展开更多
Scattering phase function is assumed to be one of the most significant factors in the inherent optical properties （lOPs） of natural water. According to three criteria proposed for assessment, several commonly used e...Scattering phase function is assumed to be one of the most significant factors in the inherent optical properties （lOPs） of natural water. According to three criteria proposed for assessment, several commonly used empirical phase functions are compared with their related practical or theoretical scattering distributions in terms of fitting errors under the circumstances of typical seawater and single-component polydisperse systems. The optimal factors corresponding to the minimum fitting errors are also calculated. It is found that both the one-term Henyey-Greenstein （OTHG） and two-term Henyey-Greenstein （TTHG） phase functions agree well with the theoretical ones for small particles, while the Fouriner-Forand （FF） phase function can be used in the case of suspensions with large suspended particles. The fitting accuracy of OTHG is the worst, FF is better and TTHG is the best.展开更多
基金supported in part by the US National Science Foundation under Grant No. 1205757 Northrop Grumman Corporation
文摘The deployment of underwater networks allows researchers to collect explorative and monitoring data on underwater ecosystems.The acoustic medium has been widely adopted in current research and commercial uses,while the optical medium remains experimental only.According to our survey onthe properties of acoustic and optical communicationsand preliminary simulation results have shown significant trade-offs between bandwidth,propagation delay,power consumption,and effective communication range.We propose a hybrid solution that combines the use of acoustic and optical communication in order to overcome the bandwidth limitation of the acoustic channel by enabling optical communicationwith the help of acoustic-assisted alignment between optical transmitters and receivers.
基金supported by the National "863" Program (No. 2006AA09Z207)
文摘Scattering phase function is assumed to be one of the most significant factors in the inherent optical properties （lOPs） of natural water. According to three criteria proposed for assessment, several commonly used empirical phase functions are compared with their related practical or theoretical scattering distributions in terms of fitting errors under the circumstances of typical seawater and single-component polydisperse systems. The optimal factors corresponding to the minimum fitting errors are also calculated. It is found that both the one-term Henyey-Greenstein （OTHG） and two-term Henyey-Greenstein （TTHG） phase functions agree well with the theoretical ones for small particles, while the Fouriner-Forand （FF） phase function can be used in the case of suspensions with large suspended particles. The fitting accuracy of OTHG is the worst, FF is better and TTHG is the best.
