GOCE mission concept, error derivation and performances

GOCE is a gravity-measuring satellite under consideration by the
European Space Agency. The satellite carries a gravity gradiometer, a GPS
receiver and a system to compensate external -non gravitational- accelerations.
The detailed study of the errors affecting the mission needs complex computer
simulations, however a simplified logic for error evaluation and for the allocation
of derived requirements has been developed. This logic is based in the analysis of
the error sources and their classification as either probabilistic or deterministic.
A classification of the error sources has been performed. This analysis has been
used to derive ”worst case” and ”most likely” performances for the mission. This
simple approach avoids over-designing while still providing excellent scientific
performances.