High Frequency electronics, July 2017, Design and Development of an On-Board System in Satellite-Based Automatic Identification Systems (AIS) Roopa Narayan Naik. Sambasiva Rao, V.

The Automatic Identification System (AIS) is mainly used to enhance the ability to identify ships and improve sailing safety. In the existing AIS, the allocation of message slots is self-coordinated only within each organized area. When several organized areas are covered during a pass of the satellite, AIS messages sent in the same time slot from different organized areas will reach the satellite simultaneously, colliding with one another. Special algorithms are required to extract the mixed signals. The main aim of this paper is to configure a system which receives mixed signals from different ships and sends them to the ground station. To process these received mixed signals, first signals are sent to satellite on board, where analog signals are converted to digital signals, stored on the Onboard System, modulated and sent to the ground station for further processing. In ground stations, demodulation is performed using special algorithms to obtain the original signals. In this pa