NORSAT-2 – Advanced Ship Tracking and VHF Data Exchange
NORSAT-2 is the fifth satellite to be constructed by the Space Flight Laboratory (SFL) for Norway. The Norwegian Space Centre (NSC) and Space Norway are leveraging the development of NORSAT-1 to enable this mission for advanced ship tracking and VHF data exchange. The NORSAT-2 satellite will carry a next generation Automatic Identification System (AIS) receiver from Kongsberg Seatex, along with a VHF data exchange (VDE) payload that will enable two-way communication at higher data rates than possible with AIS. One of the key challenges is to fit a directional VHF antenna on a small microsatellite, with NORSAT-2 being only 15 kilograms and roughly 20x30x40cm in dimensions (not including solar wings). SFL has developed a deployable crossed Yagi antenna for the satellite that allows for compact stowage during launch and simple release after ejection from the launch vehicle (Figures 1 and 2). SFL is also providing a high-speed S-band feeder uplink for the satellite, in addition to an S-band system for telemetry and command.
The VDE system (VDES) is needed to meet the growing demand for data exchange by providing additional capacity that is not available from existing AIS systems. While AIS provides for identification and position reporting/tracking of maritime vessels, VDES integrates AIS with Application Specific Messages (ASM), which are new channels with more capacity and better reliability of message delivery. Adding VDE satellite services effectively increases the range of ship to shore and ship to ship communication beyond direct line of sight. NORSAT-2 will be one of the first satellites with this capability (Figure 3).