Space-based AIS
The automatic
identification system (AIS), which sends logistic and navigation data from
ships by radio, is an important system for monitoring global shipping by radio.
This data can be picked up by satellites and relayed to the ground for
evaluation. The benefit of having this information is that it is possible to
track global shipping for logistic planning purposes, e.g. loading and
unloading at ports. As well as this, it allows ocean regions and shipping
channels to be monitored. The main criterion for the efficiency of such a
system is the refresh rate and the time delay in sending AIS data to the user.
In the case of the satellite-based receipt of AIS data, data packets from
different ships may collide as the satellite can "see" a far greater number of
ships at the same time than a ground station on account of the satellite's
altitude of some 600 km. The challenge is therefore to avoid such collisions by
utilizing innovative antenna technology and processing either on the ground or
on board the satellite so that a little AIS data as possible is lost.
In Europe, ESA and the European Commission are engaged in various activities
for developing satellite-based AIS reception. In collaboration with other
companies, OHB-System is overseeing the main ESA study concerning the
definition and configuration of a European AIS satellite array. Similarly, it
is lead-managing a study for the design of a demonstration mission for
monitoring the oceans.
