An adaptive multi-user multi-antenna receiver for satellite-based AIS detection

In the field of maritime surveillance, the space-based detection of Automatic Identification System (AIS) communications enables ship tracking and fleet monitoring with a global coverage. SAT-AIS is a joint initiative from the European Space Agency (ESA) and the European Maritime Safety Agency (EMSA) to define a sustainable space-based system that will provide AIS data to institutional organisations and other entities. The AIS communication system was not originally designed for a capture from space. As a consequence, a space-based AIS receiver faces severe technical issues, in particular a drastic amount of co-channel interferences. Astrium is working under ESA contract on an affordable SAT-AIS solution with a strong emphasis on a high-performance AIS payload and processing chain. We propose a multi-antenna AIS receiver coupled with an adaptive multi-user processing solution suited to maximize the detection of AIS messages. The proposed algorithm implements a number of diversity techniques to take advantage of the variability of received signal characteristics, especially the Direction of Arrival (DOA), incident polarization, Doppler spread, signal strength and path delay.