The Galileo Constellation Simulator was produced by us for the European Space Agency (ESA). It fulfils three important roles within the Galileo programme, namely:
To provide a means of validating the theoretical performance of the candidate Galileo signals during the Galileo signal definition phase.
To support the development of receiver terminal equipment, prior to the availability of the signals in space – an essential prerequisite if the receiver developments are to meet the stringent Galileo system timescales.
To provide a means for the formal validation of receiver terminal equipment used for critical applications.
The Galileo Constellation Simulator is capable of generating at RF, simultaneously and in real-time, each of the three Galileo satellite signals for up to 16 satellites. The signals that are produced are identical to those that would be received from the orbiting satellites, and include the effects of:
Relative motion of the satellite and receiver platforms.
Ionospheric and tropospheric propagation effects.
Fading and multipath environment of the receiver.
Satellite clock offsets and drifts, incorporating the relativistic clock effect.
Gain and phase characteristics of both satellite and receiver antennae.
Modelling of these effects by the simulator is highly flexible and configurable, using a comprehensive windows-based GUI, to support the various test cases required for receiver development and validation. Furthermore, the design of the simulator is highly modular, and will allow future upgrades to support:
Simultaneous simulation of Galileo and GPS signals.
Simultaneous simulation of the signals received at two user locations, to support differential operation.