Experimental Characterization of Underwater Visible Light Channels for Photo-Acoustic Underwater Communication

到目前为止，大部分水下无线通信都归因于使用声频，因为声频的吸收比射频（RF）低得多。通过可见光通信（VLC）的概念在使用光进行通信方面的持续进展使得光学无线与推进水下无线通信系统中的最新技术水平相关。由于低信号吸收水平，光谱呈现出用于水下通信的有利模式，特别是在紫外、紫色、蓝色和绿色波长中。以前在水下VLC方面的工作主要是理论性的，这项研究采取了一种激进的高风险方法，在现实世界的配置和设置中为水下VLC开发经验模型。本研究采用变革性的方法，探索声、光无线通信方式共存互补的光声混合通信。 光声水下通信模式可以帮助推进包括水下导航，勘探，传感和战术通信在内的众多应用。这项研究通过在现实世界条件下进行广泛的实验，弥合了构建逼真水下光声系统的知识差距，并创建了丰富的开放公共数据集，从而推进了水下网络领域。这项研究与格鲁吉亚亚特兰大附近的格温内特县水创新中心保持战略合作，从而扩大了这项工作的范围，并利用先进的设施推进水下研究。除了通过出版物传播研究成果外，该研究还涉及大学Girls-Who-Code（GWC）分会的女性学生团体进行水下研究数据收集和实验。这项研究的智力价值来自沿着两个推力在2年时间轴内执行：推力1 -水下VLC通道的经验建模。该项目的重点是在实验室和现实世界的水下场地进行广泛的水下通道建模实验和数据收集。这些数据点被用来执行经验建模的水下VLC通道沿着各种空间维度（水平，垂直，视线，非视线），沿着不同的物理参数（盐度，浊度，温度和含油量），并在移动的场景。推进2 -光声水下通信可行性研究。这一推力的重点是集成的硬件和软件的光学无线（紫外线和VLC），与声学系统的可行性。该研究在光声通信和传感的不同用例中进行实验，特别是导航和跟踪以及设备-设备通信。总之，这项研究的主要成果包括水下VLC信道的经验模型，光声通信可行性实验研究的见解和水下VLC的开放数据集。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Much of underwater wireless communication, so far, has been attributed to the use of acoustic frequencies due to the significantly low absorption than radio frequencies (RF). Ongoing advances in using light for communication through the concept of visible light communication (VLC) make optical wireless relevant to advancing the state--of--the-- art in underwater wireless communication systems. The optical spectrum presents a favorable mode for communicating underwater due to the low signal absorption levels, particularly in the ultraviolet, violet, blue and green wavelengths. Prior work in underwater VLC has largely been theoretical and this research takes a radical high-risk approach to develop empirical models for underwater VLC across real-world configurations and settings. The research takes a transformative approach and explores photo-acoustic hybrid communication in which acoustic and optical wireless communication modes co-exist and complement each other. Photo-acoustic underwater communication modalities can help advance plethora of applications including underwater navigation, exploration, sensing and tactical communications. This research advances the field of underwater networking by bridging the knowledge gap in building realistic underwater photo-acoustic systems through extensive experimentation in real-world conditions and creates a rich open public dataset. This research maintains a strategic collaboration with the Gwinnett County Water Innovation Center near Atlanta, Georgia, thus expanding the outreach of this work and advancing underwater research using advanced facilities. In addition to dissemination of research outcomes through publications, the research involves female student groups from the university Girls-Who-Code (GWC) chapter in underwater research data collection and experiments.The intellectual merits of this research are derived along two thrusts executed over a 2-year timeline: Thrust 1 - Empirical Modeling of Underwater VLC Channels. This thrust focuses on extensive underwater channel modeling experimentation and data collection in lab and real-world underwater sites. The data points are used to perform empirical modeling of underwater VLC channels along various spatial dimensions (horizontal, vertical, line-of-sight, non line-of-sight), along different physical parameters (salinity, turbidity, temperature and oiliness), and in mobile scenarios. Thrust 2 - Photo-Acoustic Underwater Communication Feasibility Studies. This thrust focuses on the feasibility of integrating the hardware and software of optical wireless (UV and VLC), with acoustic systems. The research conducts experiments across different use-cases for photo-acoustic communication and sensing, particularly for navigation and tracking and device-device communication. In summary, the key outcomes of this research include empirical models for underwater VLC channels, insights from photo-acoustic communication feasibility experimental studies and open datasets for underwater VLC.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.