62 Proceedings Spring 2025 produced three technical reports, including a technology roadmap and two summary reports on each field test respectively. The reports provided Coast Guard stake- holders with early insights on the potential adoption of VDES in the future. Current Testing and Future Outlook of VDES Ranging Mode Field Evaluation The RDC team is currently evaluating another significant feature of interest to the Coast Guard called R-Mode. In support of this testing, the RDC team established three static base stations in 2024 to form a triangular coverage area within the greater New London area and its sur- rounding waters to transmit and receive VDES R-Mode data messages. The RDC team also established VDES R-Mode “mobile” stations on local test vessels to facili- tate continuous data collection within the overlapping coverage area formed by the three base stations. The RDC team plans to use these mobile sites located within the overlapping coverage area to collect data through the end of 2025 to assess the initial implementation and performance of R-Mode signals in VDES. VDES Satellite The RDC team also plans to evaluate one of the last major components of the system in 2025, VDE-SAT, which recently achieved initial operating capability with the launch of several VDES capable “test” satellites. More launches are planned in the future to increase global cov- erage. The project seeks to evaluate the capabilities and limitations of using VDE-SAT to communicate ASM and MSI with vessels operating in polar regions, offshore, or other inshore regions with limited to no VHF coverage, like the Western Rivers. VDES represents the next generation of AIS. Besides operating on the four AIS channels, it will provide 12 additional digital communication channels—two for ASM, four for VDE-TER, and six for VDE-SAT—greatly increasing marine VHF-FM data communications. With the recent launch of several VDES satellites, the VDE-SAT component may offer an effective means for the Coast Guard to broaden STEDS communication and extend its range beyond terrestrial coverage, including areas like the polar regions, with limited to no coverage. VDE-SAT may improve the ability of both the Coast Guard and mariners to exchange MSI seamlessly across maritime boundaries to promote safe and efficient navigation and to enhance the Coast Guard’s maritime domain aware- ness in remote areas. A successful evaluation of VDE-SAT will demonstrate the capabilities and limitations of transmitting MSI on the satellite channels, as compared to the current AIS channels, and other communications alternatives. The evaluation will provide Coast Guard decision-makers with supplementary information on VDE-SAT to help inform a decision on potential implementation of VDES as a whole and future implications for the maritime industry. An evaluation of VDE-SAT will also allow the Coast Guard to continue to strengthen its collabora- tion with international partners and industry to further develop and understand VDES. As the maritime domain continues to present naviga- tional challenges, the Coast Guard remains committed to ensuring maritime safety and domain awareness. The RDC’s historical and ongoing AIS and VDES research continues to grow the body of knowledge about these technologies and maximize their utility as next-genera- tion MDA tools. These efforts demonstrate a commitment to driving innovation and advancements in maritime communication technology to enhance MDA and meet the evolving needs of maritime stakeholders. By embrac- ing VDES and its associated benefits, the Coast Guard can continue to safeguard the vast maritime expanse and maintain the highest standards of maritime safety and security. About the authors: LCDR Ryan Cassidy is a 2010 graduate of the U.S. Coast Guard Acad- emy. A career MH-65 pilot, he served as an aircraft commander and instructor pilot in both the search and rescue and rotary wing air inter- cept missions. He holds master’s degrees in information systems and business administration from the University of Maine and is the project manager for the Coast Guard Research and Development Center’s evalu- ation of VDES effort. James Spilsbury has been a project manager and physical scientist at the Coast Guard Research and Development Center for five years. He holds a bachelor’s degree in marine science from the University of Maine and master’s degrees in oceanography and business administration from the University of Rhode Island. He is also a Coast Guard-licensed boat captain 100 ton, inland. Sean Lester is a career Coast Guard MH-60 pilot and a 1991 graduate of the U.S. Coast Guard Academy. He served a tour underway on the CGC Gallatin as the navigation officer. After flight school, Lester flew tours in Clearwater, Florida, and Sitka, Alaska. He began his career in research as an active-duty lieutenant commander assigned to the Coast Guard Research and Development Center, where he extended tours and retired from active duty. He now he serves as the aviation branch chief focusing on uncrewed aerial systems and autonomy research. References: E-navigation. (n.d.) https://www.imo.org/en/OurWork/Safety/Pages/eNavi- gation.aspx#:~:text=The%20e%2Dnavigation%20concept%20is,having%20 global%20remit%20for%20shipping Gonin, I. M., Johnson, G. W., Spilsbury, J. D., Ordell, S., & Wurl, M. A. (2020). Very High Frequency Data Exchange System (VDES) Technology Roadmap. U.S. Coast Guard Research and Development Center. Retrieved August 1, 2024, from https://bit.ly/VDESRoadmap Cassidy, R. C., Johnson, G. W., Spilsbury, J.D. (2023). VDES Technology Roadmap and Evaluation Plan. U.S. Coast Guard Research and Development Center. Retrieved August 1, 2024. Lester, S. F., Johnson, G. W., Berube, K (2017). Automatic Transport of SAR Patterns
