Adaptive drop-deployable visible light communication-based underwater sensing probe
摘要
Covering under 0.1% of the ocean’s surface, coral reefs support about 30% of all marine life. Nevertheless, this fragile ecosystem is experiencing an extinction threat due to overexploitation and anthropogenically driven pressure. High-frequency and widespread observations are essential to safeguard this vital ecosystem, as well as to understand and help maintain the fragile balance. Classical acoustic sensors deliver kilometer-scale reach but suffer from low communication rates and high latency, while radio waves are severely attenuated in seawater. Underwater wireless optical communication (UWOC) has emerged as a promising technology to mitigate these drawbacks, but UWOC comes with its own challenges, such as alignment and power constraints. Herein, we report on an adaptive, drop-deployable underwater sensing probe with multi-faced visible‑light communication (VLC) receivers with simultaneous lightwave information and power transfer (SLIPT) capabilities. The proposed system was developed to overcome three major problems in UWOC systems: alignment, deployment, and long-term powering. Our proposed solution features a supported vector machine (SVM), enhanced communication with no processing penalties for the sensing probe, and embedded data compression for optimizing data storage for long-term deployment. A maximum throughput of 1.05 Mbps with a bit-error rate (BER) of 2.6 × 10−³ was achieved for uplink, equivalent to 21.7 days of continuous data recording transmitted per second, and 9.6 Kbps error-free for downlink. Simulation, experimental, and deployment results are presented in this work. A total of four sensors are used to assess environmental conditions regarding underwater temperature, light intensity, conductivity, sea current, and tidal patterns.