  High-quality time series provided by space instrumentation such as CoRoT and
Kepler, allow us to measure modulations in the light curves due to changes in
the surface of stars related to rotation and activity. Therefore, we are able
to infer the surface (possibly differential) rotation rate. However,
instrumental perturbations can also produce artificial modulations in the light
curves that would mimic those of truly stellar origin. In this work we will
concentrate on Kepler observations in order to review an optimal way to extract
reliable surface rotation rates.
