In the field of transport and logistics, cargo positioning and tracking plays an important role. A dedicated system called the Automatic Identification System (AIS) is used in the marine traffic to broadcast messages containing information about the vessel: id, payload, size, speed, destination etc. used primarily for ship collision avoidance. Due to geographical and physical reasons, AIS system is used regionally and it is not suited for traffic observation in areas far from the coast. Vessels broadcast AIS messages with different frequency rate depending on the current speed of movement. In areas with increased traffic density, packet collisions would appear. Such collisions are avoided using the Self-Organized Time Division Multiple Access technology implemented into the AIS. This principle ensures self-organization of broadcasted messages in a local area, but when observed from space, the collision of simultaneously transmitted messages is inevitable. Nano-satellites are small and cheap solution for research needs with very limited payload intended for a specific mission. Using a nano-satellite for AIS monitoring could provide data about vessel traffic in distant off-coast areas and give an insight into the collision of AIS messages in high density traffic areas. One of the problems is to build the payload for the satellite -a flexible and efficient AIS receiver system that meets low energy, size and weight requirements. Embedded platforms like Raspberry Pi and PandaBoard are a cheap alternative to traditional computing solutions with enough computing power to be suitable for advanced signal processing also meeting the requirements for low power usage in satellite systems. Easy software development and adaptation for the ARM architecture makes these boards an optimal platform for development. FUNcube Dongle, developed as a part of AMSAT-UK's FUNcube satellite project, is a very small software-defined radio receiver designed to make collecting of information from space available to anyone. In a combination with a small embedded platform like Raspberry Pi and a software for AIS decoding it can be used as the AIS receiver in a nanosatellite. GNU Radio is an open-source software development toolkit for software-defined radio solutions which combined with Linux operating systems like Debian or Angstrom and a control service create the base for generic software defined radio nano satellite system - easily adaptable and reconfigurable even in an orbital environment.
