Feasibility of wireless data transmission on ships

Abstract

This report will present the results of an investigation into the feasibility of several modes of wireless data transmission including: (1) radio frequency modems, (2) acoustic modems (using the ship's steel hull for a path with a "HullPhone"), (3) power line systems, such as X-lO units, and (4) possible power line utilization of telephone modems. There is a need for wireless data transmission on both Voluntary Observing Ships (VOS) and research ships for short-term installations. The availability of cables from remote areas on these ships is usually not good, and restrictions on installing cables prevent some useful measurements from being made. A case in point is the real time availability of measurements of sea surface temperature (SST) from VOS by sensors mounted inside the hull. Instruments for measuring SST are installed in sealed compartments that are near the waterline of the ship and often four decks below the main deck. Other applications include transmission of data from automated XBT launchers located on the aft deck to the science area and transmission of data from a cluster of meteorological instruments located at the bow of the ship to the bridge for interface to Service Argos or Inmarsat satellte links. Surveys of existing equipment have been made. Typical equipment has been purchased and tested in a ship environment, including the "HullPhone." The results of these tests are presented. Suggestions for system configurations to meet the applications noted above are made with note of the product development required.