Collection of Weather Observations via Shipboard Automatic Identification System (AIS)

Obtaining weather observations on the high seas is critical for forecasting weather, especially severe storms. However, it is difficult and expensive to obtain these observations through fixed stations such as buoys. Currently ships voluntarily submit weather observations to NOAA via the Voluntary Observing Ship (VOS) program. However, this data is submitted infrequently, typically four times per day and is a manual process. One method being explored to automate and increase the frequency of data submittal is by using the Automatic identification System (AIS).

Most commercial ships that sail on the high seas are required to carry a Class A AIS transceiver. An AIS message 8 (broadcast binary message) may be transmitted by these devices simply by sending the transceiver an appropriately formatted sentence. Weather data, either automatically or manually collected, can be embedded in an AIS message 8 (an Application Specific Message) and transmitted by the ship automatically. This transmission will be received by terrestrial base stations (when in range) or by satellite AIS receivers. The AIS weather data can then be converted into the appropriate format and forwarded for use by weather forecasters automatically. By leveraging this installed base of AIS transmitters, the volume of deep-sea weather observations could be greatly increased.

The US Army Corps of Engineers (USACE), Maritime Administration (MARAD), and NOAA National Weather Service (NWS) have been exploring the feasibility of this concept. Following several lab tests, an initial proof-of-concept was tested aboard a moored vessel in Baltimore in October 2018. After this successful demonstration, a prototype was installed on the Massachusetts Maritime Academy training ship during her training cruise in Jan-Feb 2019. During this cruise, weather data was transmitted via the ship’s AIS transceiver at 3-minute intervals. Several different ASM formats were tested, including two developed specifically for this test to improve satellite reception. In mid-2019, equipment was installed aboard several commercial vessels sailing in the Pacific and Atlantic oceans. This report will discuss the concept, the demonstrations, and the results to date including the efficacy of the various ASM formats in delivering weather observations via terrestrial and satellite based AIS receiver networks.