Free Space Optical Communication for Ocean Surface Transceivers

Sonobuoy systems are used to detect and determine the location, course and speed of underwater vehicles such as submarines and Unmanned Underwater Vehicles (UUVs). Multiple sonobuoy transmit and receive pairs are typically deployed over a large area, nominally a 40 nautical mile diameter. Current systems rely on VHF radios to continuously offload data to overhead aircraft. While this approach has proved to be effective, the upload data rates are severely limited and the power consumption of the RF transmitter is a significant portion of the total system power, limiting the duration of these missions.To address these issues, SA Photonics has developed a concept design for NeptuneLite, a low cost, low power Free-Space Optical (FSO) communication system specifically designed to offload data from receive sonobuoys. During the Phase I program, we analyzed and developed a complete concept design to support sonobuoy FSO links. A thorough system analysis was performed to validate the performance of the communication link as well as the tracking and acquisition systems. The result was a concept design for a prototype system that will be developed on this Phase II program.